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Tytuł:
The application of CFD in the assessment of the patency of the upper respiratory tract
Autorzy:
Marków, Magdalena
Janecki, Daniel
Misiołek, Maciej
Warmuziński, Krzysztof
Powiązania:
https://bibliotekanauki.pl/articles/1401684.pdf
Data publikacji:
2016
Wydawca:
Index Copernicus International
Tematy:
computational Fluid Dynamics
air flow
larynx
Opis:
Computational Fluid Dynamics is a rapidly developing instrument with a number of practical applications. CFD simulations have been used for years in aerodynamics, engineering, hydraulics, meteorology, construction, and many other fields. In medicine it was used primarily in pulmonology and cardiology, the areas in which the dynamic properties of the gas and liquid play an important role in the proper functioning of the body. In laryngology, Computational Fluid Dynamics (CFD) is a useful method, which allows calculation and visualization of the changing parameters of air flow in the upper respiratory tract.
Źródło:
Polski Przegląd Otorynolaryngologiczny; 2016, 5, 3; 24-27
2084-5308
2300-7338
Pojawia się w:
Polski Przegląd Otorynolaryngologiczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of 3D flow solver in education of students
Autorzy:
Kosowski, K.
Powiązania:
https://bibliotekanauki.pl/articles/1931592.pdf
Data publikacji:
2002
Wydawca:
Politechnika Gdańska
Tematy:
computational fluid dynamics CFD
CFD
education
Opis:
The development of 3D numerical methods enables the estimation of flow parameters in any section of the channels and in this way the complex phenomenon of generation of losses can be investigated. Application of 3D solver helps in better understanding of flow behaviour in turbine stages, while basing on the results of calculations of stages of different geometries, it is possible to show the effect of different design parameters on the turbine stage output and its efficiency. The paper presents the examples of application of modern computer programs for teaching turbomachinery problems, for research flows in turbine stages and for solving design tasks. Some examples of students' projects are also included.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2002, 6, 4; 621-629
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical analysis of the steam flow past the turbine blade stage
Autorzy:
Rogowski, K.
Pawlicki, J.
Powiązania:
https://bibliotekanauki.pl/articles/99392.pdf
Data publikacji:
2017
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
computational fluid dynamics
steam turbine
turbulence model
Opis:
The steam flow past a last stage (the eleventh stage) of the high pressure part of the TK120 steam turbine was investigated using computational fluid dynamics (CFD). The simulations are performed using the unsteady compressible Navier-Stokes equations. Viscous steam flow has been analyzed using the Spalart-Allmaras turbulence model. The paper presents distributions of instantaneous flow parameters around turbine blades as well as instantaneous aerodynamic blade loads. Flow parameters such as: velocity and static pressure are presented as contour maps whereas aerodynamic loads, axial and circumferential, are given as functions of time. Theoretical power of the examined turbine stage is 4.11 MW. Based on the numerical investigations the power of the analyzed stage is evaluated to be 3.5 MW. All presented in this paper results have been performed using the ANSYS Fluent solver.
Źródło:
Journal of Machine Engineering; 2017, 17, 2; 102-110
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Computational prediction of the resistance of the the floatplane at various trim angles
Autorzy:
Sulisetyono, Aries
Fadhlurrohman, Ihsan
Ali, Baharudin
Zubaydi, Achmad
Powiązania:
https://bibliotekanauki.pl/articles/2086974.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
resistance
floatplane
trim angle
computational fluid dynamics
Opis:
The prediction of the total resistance occurred during operation of a floatplane on the water surface is an important aspect in developing the floater as well as the engine power required. Theoretically, the trim angle of the floater may affect the total resistance. This paper intends to find the optimal trim angle for the take-off operation using the computational fluid dynamics (CFD) software. The floater set up under a fixed trim angle includes 2◦, 5◦ and 10◦ taken in simulation at five different speeds between 9.21 m/s and 15.87 m/s. In one case of 2◦ trim angle, the floater model test has been carried out in a tow tank laboratory to validate the accuracy of the numerical result. Comparison of both results has a good fit with an average error of 2.27%. In the final simulation results, the optimum trim angle is 5◦, which produces the total resistance less than 2◦ and 10◦ of the trim angle with average differences of 9.21% and 50.46% for all speeds, respectively.
Źródło:
Journal of Theoretical and Applied Mechanics; 2022, 60, 2; 267--278
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hydrodynamic Analysis of Trimaran Vessels
Autorzy:
Javanmardi, M. R.
Jahanbakhsh, E.
Seif, M. S.
Sayyaadi, H.
Powiązania:
https://bibliotekanauki.pl/articles/258654.pdf
Data publikacji:
2008
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
trimaran
resistance
maneuvering
computational fluid dynamics (CFD)
Opis:
Trimaran vessels are developed for different applications and hydrodynamic behavior of such vessels is different than usual mono-hulls. In this paper hydrodynamic resistance and maneuvering of a trimaran with Wigley body form are investigated. The effects of outriggers position in four different longitudinal and two transverse locations are studied. For hydrodynamic simulations a CFD code has been developed and used. This code is capable for simulating three dimensional, time dependent, two phases, viscous flow coupled with rigid body motion. Formulation and solution algorithm are described in detail. Different case studies have been performance and numerical results have shown good agreement with experimental data. Based on resistance and maneuvering simulation of the trimaran vessels different conclusion are made. The results show that positions of outriggers have great effect on resistance and maneuverability of trimaran. The present method can be further employed to investigate other hydrodynamic qualities of trimaran vessels.
Źródło:
Polish Maritime Research; 2008, 1; 11-18
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A CFD Study of the Aerodynamic Characteristics of Twardowsky and FOK Rockets
Autorzy:
Sahbon, Nezar
Murpani, Siddharth
Michałów, Maciej
Miedziński, Dariusz
Sochacki, Mateusz
Powiązania:
https://bibliotekanauki.pl/articles/36452599.pdf
Data publikacji:
2022
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Lotnictwa
Tematy:
computational fluid dynamics
sounding rockets
aerodynamics
modeling
Opis:
Stability and performance are crucial characteristics for aerospace vehicles. The ability to investigate the aerodynamics and performance of rockets gives an insight into their stability before flight and the potential for design and performance enhancements. For the past 13 years, the Rocketry Division within the students’ Space Association of Warsaw University of Technology has been developing sounding rockets of different designs and mission profiles. Two rockets have been chosen for the CFD (Computational Fluid Dynamics) campaigns, FOK and Twardowsky. This paper describes the mathematical model of aerodynamic loads used by the Division for sounding rocket simulation, followed by CFD campaigns for the two rockets. The results of the CFD analysis are then used to calculate the rockets’ aerodynamic derivatives according to a previously defined mathematical model.
Źródło:
Transactions on Aerospace Research; 2022, 1 (266); 35-58
0509-6669
2545-2835
Pojawia się w:
Transactions on Aerospace Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical simulations of gap flow above rotating disk
Autorzy:
Wasilczuk, F.
Flaszyński, P.
Doerffer, P.
Powiązania:
https://bibliotekanauki.pl/articles/1938643.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska
Tematy:
computational fluid dynamics CFD
internal flow
flow control
Opis:
A rotating disk can be considered a basic configuration for the investigations of the impact of various conditions on the flow through the clearance between the shrouded turbine blade and the casing. Numerical calculations using Fine/Turbo Numeca were conducted to examine the influence of the rotational velocity and the pressure difference across the disk on the flow conditions, especially the mass flow through the clearance. The results were validated using the experimental data. Moreover, the flow field was investigated to reveal the vortices induced in the flow. The calculations showed a significant drop of the mass flow with a rise of the rotation velocity. Additionally, the vortex created upstream of the disk at higher rotation velocities was observed. The phenomenon of separation at the edge of the disk was investigated.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2015, 19, 2; 89-100
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A complete design of ship propellers using the new computer system
Autorzy:
Koronowicz, T.
Krzemianowski, Z.
Tuszkowska, T.
Szantyr, J. A.
Powiązania:
https://bibliotekanauki.pl/articles/258618.pdf
Data publikacji:
2009
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
ship propellers
design methods
computational fluid dynamics (CFD)
Opis:
The computer system presented in this article is composed of several program blocks for the complete design of ship propellers. The design calculations are based on a combination of the modified lifting line theory and on the vortex lifting surface theory. The system enables solution of the following design problems: - calculation of the scale effect on the ship wake velocity field, including the influence of the propeller and rudder on this field at the propeller location - maximization of the propulsive efficiency - optimization of the propeller blade geometry on the basis of the compromise between the cavitation and blade strength requirements - optimization of the number of propeller blades and blade geometry on the basis of the acceptable level of induced pressure pulses and unsteady shaft bearing forces - calculation of the blade spindle torque for the controllable pitch propellers. The computer system is equipped with many numerical options for graphical visualization of the input data, including an easy possibility of their correction and control of the intermediate and final results of calculations.
Źródło:
Polish Maritime Research; 2009, 1; 29-34
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On general-purpose turbulence models in CFD
Autorzy:
Pozorski, J.
Powiązania:
https://bibliotekanauki.pl/articles/175545.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
computational fluid dynamics
turbulence modeling
Reynolds-averaged approaches
Opis:
The computational fluid dynamics (CFD) tools for various flow problems have become widespread nowadays, yet their use still needs attention and care. In particular, turbulence models are often a crucial part of flow computations undertaken with various software packages, either commercial, open-source or in-house. In the paper, an overview of available model categories is provided, together with some discussion of their advantages or drawbacks with respect to flow cases of interest.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2015, 127; 45-62
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An estimation of conditions inside construction works during a fire with the use of Computational Fluid Dynamics
Autorzy:
Sztarbała, G.
Powiązania:
https://bibliotekanauki.pl/articles/201986.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
computational fluid dynamics (CFD)
fire
buildings
ventilation systems
Opis:
The aim of this paper is to present the application of Computational Fluid Dynamics (CFD) to the assessment of conditions inside construction works during a fire. The CFD method is now commonly used to support the design process of fire safety in construction works. This method is very useful at the preliminary stage of design because it is possible to check the internal environment during a fire and evaluate whether requirements of fire safety are met.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2013, 61, 1; 155-160
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical model to study the combustion process and emissions in the Wartsila 6L 46 four-stroke marine engine
Autorzy:
Lamas, M. I.
Rodriguez, C. G.
Powiązania:
https://bibliotekanauki.pl/articles/259746.pdf
Data publikacji:
2013
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
marine engine
emissions
combustion
CFD Computational Fluid Dynamics
Opis:
The aim of the present paper is to develop a computational fluid dynamics (CFD) analysis to study the combustion process in a four-stroke marine diesel engine, the Wärtsilä 6L 46. The motivation comes from the importance of emissions from marine engines in the global emissions, particularly for nitrogen oxides (NOx) and sulfur oxides (SOx). The pressure and temperature fields were obtained, as well as the exhaust gas composition. In order to validate this work, the numerical results were satisfactory compared with experimental ones, which indicates that this model is accurate enough to reproduce the fluid pattern inside the cylinder during the combustion process. Accordingly, the aim of future works is to use this numerical procedure to optimize the performance and reduce the emissions of the new marine engine designs.
Źródło:
Polish Maritime Research; 2013, 2; 61-66
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Turbulent flow modelling using EARSM on parallel computers
Autorzy:
Sillen, M.
Powiązania:
https://bibliotekanauki.pl/articles/1955800.pdf
Data publikacji:
2001
Wydawca:
Politechnika Gdańska
Tematy:
aviation
computational fluid dynamics CFD
aerodynamics of airplanes
Opis:
The compressible Navier-Stokes equations are solved numerically for turbulent transonic aerospace applications on parallel computers. The turbulence is modelled by an Explicit Algebraic Reynolds Stress Model (EARSM). Expressing the EARSM as an extension of an eddy-viscosity model makes the implementation straightforward in a flow solver with existing two-equation eddy-viscosity models. The k-w transport equations are used as a platform for the model. The EARSM approach significantly improves the shock position for transonic flow over wings without substantial increase in computational cost. Industrial use of advanced flow modelling requires a short turn-around time of computations. This is enabled through the use of parallel computers. To achieve good parallel performance the computational load has to be evenly distributed between the processors of the parallel machine. A heuristic algorithm is described for distributing and splitting the blocks of a structured multiblock grid for a good static load balance. Speed-up results are presented for turbulent flow around a wing on a number of parallel platforms.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2001, 5, 2; 247-260
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Gas dynamics of the exhaust diffusers: computational aspects
Autorzy:
Solodov, V. G.
Powiązania:
https://bibliotekanauki.pl/articles/1967649.pdf
Data publikacji:
2001
Wydawca:
Politechnika Gdańska
Tematy:
gas dynamics
diffusers
exhaust devices
CFD
computational fluid dynamics CFD
Opis:
Some recent advances in computational gas dynamics of exhaust diffusers are presented. The compressor/turbine axial-radial exhaust diffusers and outlet devices of compressor/turbine units, exhaust hoods for power steam turbines are considered. The peculiarities of gas dynamics of the above mentioned devices are discussed. The formulations of problems for CFD analysis of these devices are discussed including the coupling procedure for joint operation of the last stage and exhaust hood. The numerical method and the implementation of a differential turbulence model are described. The new approach to the description of computational domain and parallel numerical solution of transport equations based on the unstructured set of structured grid blocks is also presented.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2001, 5, 4; 495-517
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental study and numerical simulation of the water entry of a ship-like symmetry section with an obvious bulbous bow
Autorzy:
Wang, Qiang
Yu, Pengyao
Zhang, Boran
Li, Guangzhao
Powiązania:
https://bibliotekanauki.pl/articles/1955603.pdf
Data publikacji:
2021
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
water entry
bow-flare sections
slamming
Computational Fluid Dynamics
Opis:
A bulbous bow is a typical ship structure. Due to the influence of the bulbous bow, complex flow separation and gas capture phenomena may appear during the water entry of ship-like sections. In this paper, experimental and numerical studies on the water entry of a ship-like section with an obvious bulbous bow are carried out. Two thin plates are installed at both ends of the test model to ensure that the flow field during the impact process is approximately twodimensional. The free-fall drop test is carried out in the test rig equipped with guide rails. By changing drop heights, impact pressure on the model surface with different initial impact velocities is measured. A numerical model for simulating the water entry of the ship-like section is established by using the Computational Fluid Dynamics (CFD) method, based on the Navier-Stokes equations. Reasonable time steps and mesh size are determined by convergence analysis. Four different flow models are used in the numerical analysis. It is found that the K-Epsilon turbulence model can present the most reasonable numerical prediction by comparing numerical results with the experimental data. Furthermore, the influence of the bulbous bow on the impact loads is numerically studied by using the validated numerical model. It suggests that the bulbous bow has little effect on the impact force acting on the bow-flared area but, in the position near the bulbous bow, the pressure will be affected by the second slamming and the air cushion.
Źródło:
Polish Maritime Research; 2021, 3; 16-34
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical investigation of the secondary flow development in turbine cascade
Autorzy:
Doerffer, P.
Rachwalski, J.
Magagnato, F.
Powiązania:
https://bibliotekanauki.pl/articles/1955810.pdf
Data publikacji:
2001
Wydawca:
Politechnika Gdańska
Tematy:
turbines
computational fluid dynamics CFD
secondary flow
wind turbines
Opis:
The results represent the first attempt of the numerical analysis of 3-D secondary flows formed in the linear turbine cascade wind tunnel. Numerical simulations were carried out by means of the SPRC code. It was possible to make presented here calculations thanks to the cluster of PC's providing sufficient computational resources. In order to be able to verify the obtained results the case considered is the workshop test case (D.G.Gregory-Smith 1994 Turbomachinery Workshop Test Case No.3 116). It has been shown that the obtained results are in a very good agreement with experiment. It gave confidence in the results and several important conclusions concerning the development of streamwise vortices could be made thanks to the work carried out.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2001, 5, 2; 165-178
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical Analysis of Flow Structure in Reciprocating Compressor
Autorzy:
Demircan, Tolga
Yaman, Ali Burak
Powiązania:
https://bibliotekanauki.pl/articles/1165510.pdf
Data publikacji:
2018
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
CFD
Reciprocating compressor
computational fluid dynamics
inlet input angle
Opis:
In line with current rapidly developing technology, mechanization in industry is increasing. In this case, all components that form a machine are becoming important. Compressor plays an important role in operations of numerous machineries. They are used for increasing pressure by compressing gas. Compressors have various types and especially in industries such as automotive, textile, and manufacturing, reciprocating compressors are frequently used. Reciprocating compressors consist of cylinder, piston, and crank and connecting rod mechanism. These components work by narrowing the volume inside the cylinder and increasing gas pressure inside. In this study, flow structure inside a reciprocating compressor was numerically analysed. For this purpose, models were created for 2 different crank angles of a reciprocating compressor. Simulations were made for different pipe angles of inlet pipe and outlet pipe. Valve openings were kept constant at 6 mm. Input and output angles of inlet and outlet pipes to cylinder was changed as 0°, 30°, 45°, 60° and 90°. As a result, it was determined that as the angle of inlet and outlet pipes changed, general flow structure inside the cylinder changed as well. Especially, there were differences in velocity vectors plotted for input and output of the flow from valve to cylinder.
Źródło:
World Scientific News; 2018, 107; 160-170
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation of fluid flow with interacting particles
Autorzy:
Górecki, R.
Mars, M.
Alda, W.
Fioretti, L.
Rybicki, J.
Powiązania:
https://bibliotekanauki.pl/articles/1964083.pdf
Data publikacji:
2001
Wydawca:
Politechnika Gdańska
Tematy:
computational fluid dynamics CFD
particle methods
porous media
sedimentation
Opis:
In the paper a method for modeling flows in the presence of interacting particles is briefly presented. The method is based on merging classical, continuous approach of numerical solution of Navier-Stokes equations on the 2D mesh with discrete particles interacting with the fluid and among themselves by means of central and friction forces. Several sample simulations have been described presenting the flow through porous medium and convection flow driven by sedimentation.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2001, 5, 1; 59-69
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
CFD computation of the savonius rotor
Autorzy:
Rogowski, K.
Maroński, R.
Powiązania:
https://bibliotekanauki.pl/articles/280680.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
vertical axis wind turbine
simulation
computational fluid dynamics (CFD)
Opis:
In this paper, Computational Fluid Dynamics (CFD) analysis of a two-dimensional two- -bucket Savonius rotor, using ANSYS Fluent solver, is presented. Computational methods of fluid dynamics are used to estimate the aerodynamic forces acting on the rotor, the torque and the power extracted by the Savonius rotor. In addition, an analysis of the results for different turbulence models is performed. Numerical investigations are compared with the experiment of the Sandia National Laboratories.
Źródło:
Journal of Theoretical and Applied Mechanics; 2015, 53, 1; 37-45
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical analysis of the intake vortex formation in the case of a double fuselage shielded inlet
Autorzy:
Kozakiewicz, A.
Frant, M.
Powiązania:
https://bibliotekanauki.pl/articles/281631.pdf
Data publikacji:
2014
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
turbine jet engine
inlet intake vortex
computational fluid Dynamics
Opis:
The paper raises a very important problem, concerning the work of turbine-jet engines, that is the intake vortex. A phenomenon which is relevant to all engines of this type. The article demonstrates literature data determining the influence of the airflow direction and zone on the possibility of vortex formation, taking into consideration the influence of basic geometrical data. The outcomes of calculations related to the formation of the inlet vortex for a given fuselage shielded inlet constructional system are shown. The studies are concerned with determination of the influence of angles and the gust speed value on forming of the vortex in this kind of intake.
Źródło:
Journal of Theoretical and Applied Mechanics; 2014, 52, 3; 757-766
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Flow analysis of hydraulic poppet control valve by means of computional fluid dynamics
Autorzy:
Łazowski, J.
Krasucki, J.
Powiązania:
https://bibliotekanauki.pl/articles/248062.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
poppet control valve
computational fluid dynamics (CFD)
flow characteristics
Opis:
The poppet control valve is one of the most widespread hydraulic components. The paper purpose is the evaluation of flow characteristics of poppet valve by means of a complete numerical analysis. The aim of this analysis is to evaluate the valve fluid dynamic performance, exploiting computational fluid dynamics (CFD) techniques, in order to give the reliable indications needed to define the valve design criteria and avoid expensive experimental tests. The numerical analysis was performed by using the commercial code of CFD, and the numerical results show the complete flow field inside the valve. Axisymmetric as well as three-dimensional valve model was considered and the simulation results also are verified with experimental results. The results have confirmed the good accuracy of the simplified CFD analysis based on 2D axisymmetric valve model being more efficient than full 3D approach and show this method as very useful to forecast flow characteristics of poppet control valves. Hydraulic control poppet valve, distribution of the velocity in layers of the fluid, computational grid in the modelled geometry, pressure distribution for axisymmetric and three-dimensional mode for different flow rate, fluid velocity distribution in valve metering section for axisymmetric and three-dimensional model for different flow rates, the example of streamlines, the comparison of flow characteristics are contained in the publication.
Źródło:
Journal of KONES; 2012, 19, 1; 251-259
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical model to study the valve overlap period in the Wärtsilä 6L 46 four-stroke marine engine
Autorzy:
Lamas, M. I.
Rodríguez, C. G.
Rebollido, J. M.
Powiązania:
https://bibliotekanauki.pl/articles/259055.pdf
Data publikacji:
2012
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
four-stroke engine
computational fluid dynamics (CFD)
marine engine
Opis:
In this paper, a CFD (Computational Fluid Dynamics) analysis was carried out to study the Wärtsilä 6L 46 medium-speed, four-stroke marine engine. For the purpose, the commercial software ANSYS Fluent 6.3 was employed. The aim is to analyze the scavenging of gases, especially during the valve overlap period. Particularly, the pressure, velocity and mass fraction fields were numerically obtained. In order to validate the CFD results, the in-cylinder pressure was successfully compared to experimental measurements for the exhaust, intake and compression strokes of the cylinder operation. This model can be used in future works to improve the performance of these engines because the information provided is very useful to identify regions in which the pressure, velocity or distribution of gases are inadequate. Besides, to compute the quantity of burnt gases which remain inside the cylinder, fresh charge which is expelled through the exhaust valves and study the influence of parameters such as the exhaust and intake pressures, engine speed, cam profile design, etc.
Źródło:
Polish Maritime Research; 2012, 1; 31-37
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Steady and unsteady analysis of NACA 0018 airfoil in vertical-axis wind turbine
Autorzy:
Rogowski, K.
Hansen, M. O. L.
Maroński, R.
Powiązania:
https://bibliotekanauki.pl/articles/279244.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
airfoil characteristics
vertical-axis wind turbine
computational fluid dynamics
Opis:
Numerical results are presented for aerodynamic unsteady and steady airfoil characteristics of the NACA 0018 airfoil of a two-dimensional vertical-axis wind turbine. A geometrical model of the Darrieus-type wind turbine and the rotor operating parameters used for numerical simulation are taken from the literature. Airfoil characteristics are investigated using the same mesh distribution around the airfoil edges and two turbulence models: the RNG k-ε and the SST Transition. Computed results for the SST Transition model are in good agreement with the experiment, especially for static airfoil characteristics.
Źródło:
Journal of Theoretical and Applied Mechanics; 2018, 56, 1; 203-212
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
CFD analysis of the influence of flaps extension on the aerodynamic characteristics of the M-28 Bryza aircraft
Autorzy:
Szczepaniak, R.
Konopka, B.
Zahorski, T.
Bąbel, R.
Stryczniewicz, W.
Powiązania:
https://bibliotekanauki.pl/articles/243831.pdf
Data publikacji:
2016
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
M-28 Bryza
aerodynamic characteristics
flap
Computational Fluid Dynamics
Opis:
The paper presents a modelling procedure of the M-28 Bryza wing with extended flaps and Computational Fluid Dynamics (CFD) simulations results preformed in order to assess the performance of the investigated wing for various flap extension rates. The M-28 Bryza is a two-engine high-wing aircraft used in the Polish Air Force for short distance airlift of people and equipment. The aim of this work was to determine the aerodynamic characteristics of the investigated wing. The CFD simulations were performed in order to investigate the influence of flap extension on lift and drag coefficients at various angles of attack. In order to validate the results of two different commercial CFD packages were used. The findings are presented in the form of flow visualization and aerodynamic characteristics. The typical and non-standard extension rates were investigated for low, moderate and high angles of attack. The results correlated with the limitations specified in the aircraft manual. The outcome of the presented work confirmed the feasibility of the presented methodology for its use as a supportive tool for providing additional information about airplane performance in standard and non-standard conditions of flight such as landing with one engine working. The results of work might prove useful for M-28 Bryza pilots and maintenance personnel as well as for educational purposes.
Źródło:
Journal of KONES; 2016, 23, 1; 353-360
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Temperature Error Correction Method for a Thermometer Screen
Autorzy:
Yang, J.
Liu, Q.
Powiązania:
https://bibliotekanauki.pl/articles/1032598.pdf
Data publikacji:
2017-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
temperature error
surface air temperature
computational fluid dynamics
screen
Opis:
Due to solar radiation exposure, air flowing inside a thermometer screen may produce a measurement error of 0.8°C or higher. To improve the air temperature observation accuracy, a temperature error correction method is proposed. The correction method is based on a computational fluid dynamics method and a genetic algorithm method. The computational fluid dynamics method is implemented to analyze and calculate the temperature errors of a screen under various environmental conditions. Then, a temperature error correction equation is obtained by fitting the computational fluid dynamics results using the genetic algorithm method. To verify the performance of the correction equation the screen and an aspirated temperature measurement platform are characterized in the same environment to conduct the intercomparison. The aspirated temperature measurement platform serves as an air temperature reference. The mean temperature error given by measurements is 0.77°C, and the mean temperature error given by correction equation is 0.79°C. This correction equation allows the temperature error to be reduced by approximately 97.5%.
Źródło:
Acta Physica Polonica A; 2017, 132, 4; 1301-1305
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Short review of the CFD activities in Poland
Autorzy:
Kazimierski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1953991.pdf
Data publikacji:
1998
Wydawca:
Politechnika Gdańska
Tematy:
computational fluid dynamics CFD
CFD activities
universities
scientific centres
Opis:
Computational fluid dynamics is being developed at several universities and scientific centres in Poland. These centres are considered and a general description of CFD activities is provided. It should be emphasised that the centres mentioned are only the best known ones. The information provided has been prepared in co-operation with the responsible scientists and is authorised by them. Therefore the form of topics description is not uniform.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 1998, 2, 2; 199-204
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Computational fluid dynamics simulation of heat transfer from densely packed gold nanoparticles to isotropic media
Autorzy:
Radomski, Piotr
Ziółkowski, Paweł
de Sio, Luciano
Mikielewicz, Dariusz
Powiązania:
https://bibliotekanauki.pl/articles/1954995.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
heat transfer
gold nanoparticles
glasses
polymers
computational fluid dynamics
Opis:
This work aims to determine and compare heat generation and propagation of densely packed gold nanoparticles (Au NPs) induced by a resonant laser beam (532 nm) according to the Mie theory. The heat flux propagation is transferred into the materials, which here are: silica glass; soda-lime-silica glass; borosilicate glass; polymethyl methacrylate (PMMA); polycarbonate (PC); and polydimetylosiloxane (PDMS). This analysis aims to select the optimum material serving as a base for using photo-thermoablation. On the other hand, research focused only on Newtonian heat transfer in gold, not on non-Fourier ones, like the Cattaneo approach. As a simulation tool, a computational fluid dynamics code with the second-order upwind algorithm is selected. Results reveal a near-Gaussian and Gaussian temperature distribution profile during the heating and cooling processes, respectively. Dependence between the maximum temperature after irradiation and the glass thermal conductivity is observed confirming the Fourier law. Due to the maximum heating area, the borosilicate or soda-lime glass, which serves as a base, shall represent an excellent candidate for future experiments.
Źródło:
Archives of Thermodynamics; 2021, 42, 3; 87-113
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Computational fluid dynamics analysis of several designs of a Curtis wheel
Autorzy:
Koprowski, Arkadusz
Rządkowski, Romuald
Powiązania:
https://bibliotekanauki.pl/articles/1955026.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
steam turbines
curtis stage
computational fluid dynamics
partial admission
Opis:
In small steam turbines, sometimes the efficiency is not as important as the cost of manufacturing the turbine. The Curtis wheel is a solution allowing to develop a low output turbine of compact size and with a low number of stages. This paper presents three fully dimensional computational fluid dynamics cases of a Curtis stage with full and partial admission. A 1 MW steam turbine with a Curtis stage have been designed. The fully admitted stage reaches a power of over 3 MW. In order to limit its output power to about 1 MW, the partial admission was applied. Five variants of the Curtis stage partial admission were analyzed. Theoretical relations were used to predict the partial admission losses which were compared with a three-dimensional simulations. An analysis of the flow and forces acting on rotor blades was also performed.
Źródło:
Archives of Thermodynamics; 2021, 42, 3; 197-208
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Introduction to non-linear Thermal-FSI on the example of transient load of a thin-walled container
Autorzy:
Kraszewski, B.
Powiązania:
https://bibliotekanauki.pl/articles/1818166.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
thermal-FSI
CFD
computational fluid dynamics
CSD
computational solid dynamics
non-linear mechanics
Opis:
This paper presents the problems associated with the transient thermal load of structures exhibiting a non-linear relationship between load and strain. The mathematical model required to comprehensively describe the relationship between fluid and solid has been shown from different perspectives. In addition, the Newton-Raphson method has been referred to as a way of solving nonlinear equations. The article also presents the assumptions and results of numerical analysis of thin-walled container thermally loaded by contact with hot water. The conclusions drawn emphasize the importance of Thermal-FSI tools, especially in the power engineering sector.
Źródło:
Zeszyty Energetyczne; 2018, 5; 1--13
2658-0799
Pojawia się w:
Zeszyty Energetyczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fluid solid interactions – a novelty in industrial applications
Autorzy:
Ochrymiuk, Tomasz
Banaszkiewicz, Mariusz
Lemański, Marcin
Kowalczyk, Tomasz
Ziółkowski, Piotr J.
Hyrzyński, Rafał
Stajnke, Michał
Bryk, Mateusz
Kraszewski, Bartosz
Kruk-Gotzman, Sylwia
Froissart, Marcin
Badur, Janusz
Powiązania:
https://bibliotekanauki.pl/articles/2091370.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
computational fluid dynamics
computational solid dynamics
arbitrary agrangian eulerian description
fluid-solid interaction
micromechanics
nanomechanics
Opis:
The article deals with a current state-of-art of fluid solid interaction (FSI) – the new branch of continuum physics. Fluid-solid interaction is a new quality of modeling physical processes of continuum mechanics, it can be described as the interaction of various (so far treated separately from the point of view of mathematical modeling) physical phenomena occurring in continuous media systems. The most correct is the simultaneous application of the laws of the given physical disciplines, which implies that fluid solid interaction is a subset of multi-physical applications where the interactions between these subsets are exchanged on the surface in interconnected systems. Our purpose is to extend the fluid solid interaction aplications into new phenomena what follow from the industrial needs and inovative thechnologies. Selecting the various approaches, we prefer the arbitraty lagrangean-eulerian description within the bulk of fluid/solid domain and a new sort of advanced boundary condition on a surface of common contact.
Źródło:
Archives of Thermodynamics; 2022, 43, 2; 75--96
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Computational Fluid Dynamics Modeling of Residence Time Distribution in a Field-Scale Horizontal Subsurface Flow Constructed Wetland with Palm Kernel Shell as Substrate
Autorzy:
Okoye, Nelson Mbanefo
Madubuike, Chimaobi Nnaemeka
Nwuba, Ifeanyi Uba
Orakwe, Louis Chukwuemeka
Ugwuishiwu, O. Boniface
Powiązania:
https://bibliotekanauki.pl/articles/1163287.pdf
Data publikacji:
2018
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
COMSOL
Computational Fluid Dynamics
Constructed Wetland
Simulation Modelling
Wastewater Treatment
Opis:
The hydraulic performance of constructed wetlands is often compromised by hydraulic problems. Therefore, the development of an appropriate simulation model to reliably predict how various modifications of bed design and configurations might affect performance will facilitate the design of efficient systems. The aim of this research work is to determine distribution of residence time in a field-scale horizontal subsurface flow constructed wetland with Palm Kernel Shell as substrate. The governing equations of flow in porous media and transport of diluted species were solved using COMSOL Multiphysics 5.3a. The result was validated using experimental data and the model result showed good agreement with a correlation coefficient of 0.99. Alternative wetland designs were assessed for the same flow conditions. The results revealed that a two cell wetland improved short-circuiting flow paths.
Źródło:
World Scientific News; 2018, 109; 60-70
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wind turbine operation parameter characteristics at a given wind speed
Autorzy:
Kamiński, Z.
Czyż, Z.
Wendeker, M.
Powiązania:
https://bibliotekanauki.pl/articles/103129.pdf
Data publikacji:
2014
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
wind turbine
renewable energy
computational fluid dynamics (CFD)
numerical analysis
Opis:
This paper discusses the results of the CFD simulation of the flow around Vertical Axis Wind Turbine rotor. The examined rotor was designed following patent application no. 402214. The turbine operation is characterised by parameters, such as opening angle of blades, power, torque, rotational velocity at a given wind velocity. Those parameters have an impact on the performance of entire assembly. The distribution of forces acting on the working surfaces in the turbine can change, depending on the angle of rotor rotation. Moreover, the resultant force derived from the force acting on the oncoming and leaving blades should be as high as possible. Accordingly, those parameters were individually simulated over time for each blade in three complete rotations. The attempts to improve the performance of the entire system resulted in a new research trend to improve the performance of working turbine rotor blades.
Źródło:
Advances in Science and Technology. Research Journal; 2014, 8, 22; 75-82
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical simulation of 3D viscous turbomachinery flow with high-resolution ENO scheme and modern turbulence model
Autorzy:
Yershov, S. V.
Rusanov, A. V.
Powiązania:
https://bibliotekanauki.pl/articles/1967653.pdf
Data publikacji:
2001
Wydawca:
Politechnika Gdańska
Tematy:
CFD
computational fluid dynamics CFD
turbomachinery
Navier-Stokes equation
turbulence
Opis:
This paper presents the basic principles of construction of numerical models for 3D viscous turbulent flows through multi stage turbomachines. The great attention is given to such properties of the methods as accuracy, linear and non-linear stability, robustness and computational efficiency. It is shown that these properties can be guaranteed if the implicit Godunov’s type ENO scheme is used. A 3D code FLOWER has been developed within this concept. Using the code the numerical results are obtained for flows through high loaded compressor cascades, a turbine stage, a low-pressure multi stage turbine and a centrifugal compressor stage. The results of optimisation of a low-pressure turbine last stage are presented.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2001, 5, 4; 459-476
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Jet and droplet breakup modelling approaches
Autorzy:
Kapusta, Ł. J.
Jaworski, P.
Kowalski, J.
Powiązania:
https://bibliotekanauki.pl/articles/245813.pdf
Data publikacji:
2015
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
spray
modelling
simulation
breakup
injection
CFD
computational fluid dynamics (CFD)
Opis:
Three-dimensional computational fluid dynamics (CFD) plays important role in engines development. The mixture formation in a direct-injection piston engines poses a huge challenge in successful simulations of the engine processes. It is due to the fact that the spray as a two-phase flow complicates the computational process. Moreover, this multiphase flow is not uniform. Three main zones, depending on the distance from the nozzle exit are visible when a liquid is injected. Very dense so called “thick” in a direct vicinity of the injector hole, than “thin” as a result of pri-mary breakup downstream the injector and finally in the certain distance from the injector appears “very thin” region as a result of secondary breakup. It is important to take into account that the liquid phase in various regimes behaves differently and is under influence of different phenomena. The modelling approach needs to take in to consideration all those elements. This paper focuses on presentation of the theory and numerical models for primary and secondary breakup phenomena. The primary breakup is a process that results from a combination of three mechanisms: turbu-lence within liquid phase, implosion of cavitation’s bubbles and aerodynamic forces acting on a liquid jet. Secondary breakup regime occurs mainly due to the aerodynamic interactions between the liquid and the gaseous phase.
Źródło:
Journal of KONES; 2015, 22, 3; 83-90
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A complete design of ducted propellers using the new computer system
Autorzy:
Koronowicz, T.
Krzemianowski, Z.
Tuszkowska, T.
Szantyr, J. A.
Powiązania:
https://bibliotekanauki.pl/articles/258682.pdf
Data publikacji:
2009
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
ship propellers
ducted propellers
design methods
computational fluid dynamics (CFD)
Opis:
The computer system for the completed design of the ducted ship propellers has some common blocks and procedures with the analogical system for open propellers that has already been presented in detail in the Polish Maritime Research [1]. This article describes only these blocks and procedures which are specific for the design of ducted propellers. These new blocks concern first of all the procedures for the design calculation of ducted propellers and for the analysis of the ducted propeller operation in the non-uniform velocity field behind the ship hull. The comparative analysis of computation results for different types of ducts is also presented.
Źródło:
Polish Maritime Research; 2009, 2; 34-39
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Badania numeryczne możliwości intensyfikacji wymiany ciepła z wykorzystaniem zjawiska streamingu akustycznego
Autorzy:
Machaj, Krystian
Malecha, Ziemowit
Powiązania:
https://bibliotekanauki.pl/articles/37217970.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
konwekcyjna wymiana ciepła
streaming akustyczny
Computational Fluid Dynamics
efekt barokliniczny
Opis:
W pracy przeprowadzono badania numeryczne streamingu akustycznego, wywołanego ścianą drgającą z częstotliwością 20 kHz oraz 40 kHz w kanale o przekroju prostokątnym. Częstotliwość oscylacji ściany dostosowano do długości kanału tak, aby wytworzyć sinusoidalną falę stojącą. Uśredniono przepływ w kanale i pokazano strukturę przepływu będącego streamingiem akustycznym. Dodatkowo wprowadzono różnicę temperatur między górną i dolną ścianą kanału. Pokazano, że streaming akustyczny intensyfikuje wymianę ciepła między ścianami kanału oraz że jego intensywność zwiększa się wraz z różnicą temperatury między ścianami. Wskazano również na potencjalne wykorzystanie badanego zjawiska do chłodzenia elektroniki w warunkach braku grawitacji (braku konwekcji naturalnej).
Źródło:
Zeszyty Energetyczne; 2020, 7; 355-372
2658-0799
Pojawia się w:
Zeszyty Energetyczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design of the natural ventilation system for the fishing vessel by the CFD methods
Autorzy:
Sugalski, K.
Powiązania:
https://bibliotekanauki.pl/articles/358991.pdf
Data publikacji:
2014
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
fishing vessel
stern trawler
aerodynamics
ventilation
computational fluid dynamics (CFD)
Opis:
In this paper, application of the computational fluid dynamics has been presented in the process of design natural ventilation system for the fishing vessel. There are two main types of ventilation systems: natural ventilation which is used on small fishing vessels and sport craft boatsand, and forced ventilation. This type of ventilation is a common solution on all types of merchant ships. In this paper, solution of the velocity filed in the cargo hold space of the fishing vessel had been presented. Natural ventilation system has been validated using the CFD (Computational Fluid Dynamics). All calculations had been performed in the free CFD software called OpenFOAM.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2014, 40 (112); 23-26
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study on the effect of the descent rate of a helicopter in the Vortex Ring conditions
Autorzy:
Surmacz, K.
Kowaleczko, G.
Powiązania:
https://bibliotekanauki.pl/articles/248016.pdf
Data publikacji:
2016
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
Vortex Ring State
helicopter descent
computational fluid dynamics
flow simulations
Opis:
One of the limiting factors for a helicopter operation is the Vortex Ring State (VRS). This aerodynamic phenomenon, known as the VRS or “Settling with Power”, is characterized by the formation of circulating air stream moving along a ring shaped track around the main rotor of a helicopter. Conditions, conducive to development of the vortex ring state, occur in the vertical or nearly vertical descent. This leads to decrease in thrust and thus rapidly increasing the rate of descent. This phenomenon occurs for an appropriate combination of induced velocity and the velocity of the stream of airflow from the bottom to the rotor. The rates of change of velocities delimit dangerous areas of flight. The objective of this work was to investigate the influence of the descent rate of a helicopter on the vortex ring formation process and determinants of the occurrence of vortex rings. For better understanding of the nature of this state, a computational method was applied. Series of three-dimensional (3D) unsteady analysis was carried out using Computational Fluid Dynamics tools (CFD). Simulations were realized using geometry and performance of the W-3 “Sokol” helicopter. The paper presents results of a helicopter operation in axial and non-axial descent conditions. Three calculation cases of vertical flight of a helicopter with different rates of velocity changes were considered. A simulation of non-axial descent was based on the measured flight test data for the W-3 helicopter. The results provide information about the changing nature of the flow in the course of the movement of a helicopter and show the influence of the rate of descent during initiation on the development of VRS. Results of the calculations provide guidelines for helicopter pilots.
Źródło:
Journal of KONES; 2016, 23, 1; 345-352
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of the rans flow model for the analysis of the motion of floating objects in waves
Autorzy:
Kraskowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/248052.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
computational fluid dynamics (CFD)
ship
drilling platform
mooring
model tests
Opis:
The present paper describes a proposal of the method for simulating the motion of freely floating and moored objects in waves, based on the RANS (Reynolds Averaged Navier-Stokes Equations) flow model. Attempts on using this model for simulating the floating body dynamic started quite recently due to its large requirements for the computer power. Only in the past few years such analyses became more common, however, no unique approach can be observed due to large variety of existing possibilities, numerical methods etc. The paper includes the description of the proposed method, which consists in mesh generation technique, efficient wave generation method, and the mooring system module, as well as two samples of marine applications: analyses of the motion of fishing vessel in head waves and the motion of moored semi-submersible drilling platform. The results were verified basing on the towing tank experiments, conducted by Centrum Techniki Okrętowej (Ship Design and Research Centre) S.A. Generating the waves by prescribed wave motion on both ends of the domain, generating the waves by prescribed wave motion and suppressing them in the damping zone, sliding mesh example, mooring system scheme, forcedisplacement characteristics of the mooring chain, fishing vessel in head waves, heave motion history, outline of the semi-submersible are presented.
Źródło:
Journal of KONES; 2012, 19, 1; 199-206
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fishing vessel hull design and towing resistance calculation by the CFD methods
Autorzy:
Sugalski, K.
Powiązania:
https://bibliotekanauki.pl/articles/360672.pdf
Data publikacji:
2014
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
fishing vessel
stern trawler
resistance calculation
computational fluid dynamics (CFD)
Opis:
Hull resistance and propulsion calculations are the basis of every ship design. In this paper, application of the computational fluid dynamics are presented together with the results of towing resistance of the model of stern trawler. The practical use of CFD in the preliminary vessels' design process were presented at the stern trawler vessel type.All calculations had been performed in the free CFD software called OpenFOAM. This is set of C++ programming language libraries, designed to solve Navier-Stokes equations.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2014, 40 (112); 27-30
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical analysis of influence of selected elements on effectiveness of streamline rudder
Autorzy:
Abramowski, T.
Szelangiewicz, T.
Powiązania:
https://bibliotekanauki.pl/articles/258696.pdf
Data publikacji:
2010
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
streamline rudder
improvement of rudder effectiveness
computational fluid dynamics (CFD)
Opis:
During designing steering gear for large fast transport ships (e.g. container carriers), shipowners usually put forward strong demands concerning ship manoeuvrability. It means that streamline rudders should be characterized by a high effectiveness, i.e. fast increasing values of lifting force in function of rudder angle and large values of lifting force related to rudder area. As gabarites of streamline rudder depend on a form and draught of stern part of ship’s hull, an improvement of rudder effectiveness can be reached by an appropriate selection of rudder profile and application of additional elements to rudder blade. This paper presents results of numerical investigations (by using CFD methods) of hydrodynamic forces acting on rudder blades of the same gabarites but based on different profiles. Such calculations were also performed for selected rudder blades fitted with additional elements intended for the improving of rudder effectiveness.
Źródło:
Polish Maritime Research; 2010, 3; 3-7
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Critical review of propeller performance scaling methods, based on model experiments and numerical calculations
Autorzy:
Bugalski, T.
Streckwall, H.
Szantyr, J. A.
Powiązania:
https://bibliotekanauki.pl/articles/258844.pdf
Data publikacji:
2013
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
propeller scale effects
open water tests
computational fluid dynamics (CFD)
Opis:
The article presents the results of experimental and numerical investigation of propeller scale effects, undertaken in co-operation of the Hamburg Ship Model Basin (HSVA), Germany, and Ship Design and Research Centre (CTO SA), Poland. The objective of the investigation was to test the adequacy of the methods currently used to account for the propeller scale effect and to develop possible improvement of the methods. HSVA has conducted model experiments in the large cavitation tunnel together with panel method and CFD calculations. CTO SA has performed model experiments in the towing tank, together with lifting surface and CFD calculations. Both institutions have suggested different new approaches to the problem and different new procedures to account for the propeller scale effects. In the article the procedures are presented together with the description of the underlying experimental and theoretical research.
Źródło:
Polish Maritime Research; 2013, 4; 71-79
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical analysis of volatile organic compounds concentration in A C segmnet vehicle interior – diesel engine exhoust pollution
Autorzy:
Dudycz, A.
Górniak, A.
Janicka, A.
Rodak, M.
Skrętowicz, M.
Trzmiel, K.
Włostowski, R.
Woźniak, J.
Zawiślak, M.
Powiązania:
https://bibliotekanauki.pl/articles/2073654.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
computational fluid dynamics CFD
volatile organic compounds (VOCs)
diesel engine
Opis:
In large cities the number of inhabitants constantly increases. It is caused by economic issues. The evergrowing populations causes more intense traffic and in consequence increase of air pollutions. Topology and roads configuration is conducive to the accumulation of toxic substances. Harmful substances accumulates inside the vehicles interiors which significantly deteriorate microclimate within the cabin. The study aimed to determine the amount of harmful substances getting into the interior of vehicles and their distribution have been presented in this paper.
Źródło:
Journal of Polish CIMEEAC; 2015, 10, 1; 45--52
1231-3998
Pojawia się w:
Journal of Polish CIMEEAC
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Computational fluid dynamics simulation of gas–liquid multiphase flow in T-junction for CO2 separation
Autorzy:
Wrzesień, Sylwia
Madejski, Paweł
Ziółkowski, Paweł
Powiązania:
https://bibliotekanauki.pl/articles/37215646.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
Computational Fluid Dynamics
CFD
Multiphase Flow
Numerical Simulations
T-junction
Opis:
The article presents the results of a computational fluid dynamics (CFD) analysis of gas-liquid multiphase flow. The simulation was conducted using CFD code and the Euler–Euler approach. The presented study relates to the non–reactive, steady-state, turbulent flow of water and carbon dioxide mixture in a 3D pipe. Separation phenomenon between phases is observed. The solution was obtained using a mixture model. Different values of carbon dioxide volume fraction were taken into account in the analysis of the results. The analysed cases were compared thanks to the obtained calculations results. The main purpose of the simulations was to show streamlines, velocity, pressure, and volume fraction distribution that could be useful in developing pipeline systems in many industrial applications, especially for CO2 separators.
Źródło:
Zeszyty Energetyczne; 2020, 7; 403-414
2658-0799
Pojawia się w:
Zeszyty Energetyczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Computational Fluid Dynamics (CFD) innowacyjne narzędzie do symulowania procesu wędzenia oraz modelowania elementów konstrukcji komory wędzarniczo-parzelniczej
Computational Fluid Dynamics CFD as an innovative tool for stimulating the smoke drying process and for modeling the construction elements of a smoke-drying chamber
Autorzy:
Kubiak, M. S.
Jakubowski, M.
Dolata, W.
Powiązania:
https://bibliotekanauki.pl/articles/93904.pdf
Data publikacji:
2014
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
Computational Fluid Dynamics
CFD
model symulacyjny
komora wędzarnicza
wędzenie
konstrukcja
dysza zasilająca
computational fluid dynamics (CFD)
simulation model
smoking chamber
smoking
power nozzles
construction
Opis:
Omówiono Computational Fluid Dynamics (CFD) w praktyce inżynierskiej jako integralną część postępu w całej inżynierii procesowej wędzenia z uwzględnieniem rozwoju technik i metod przeprowadzania obróbki wędzarniczej. Wykorzystanie narzędzi związanych z modelowaniem CFD pozwoliło na uzyskanie istotnych informacji dotyczących przeprowadzanego procesu wędzenia dla asortymentu o kształcie geometrycznym zbliżonym do szynki (myszka). Komora jednowózkowa stanowiła konstrukcję bazową dla rozwiązań proponowanej modyfikacji elementów zasilających (dysz), jak również geometrię modelu komputerowego samej konstrukcji komory pustej i z wsadem. Dyskretyzacja została wykonana w programie ANSYS Mechanical APDL 12.1 i na jej podstawie stworzono model o proponowanym rozwiązaniu konstrukcji dysz zasilających i rozprowadzających mieszaninę dymu wewnątrz komory wędzarniczej. Na podstawie modeli symulacyjnych i uzyskanych z nich wyników można jednoznacznie stwierdzić, że osiągnięto korzystniejsze warunki rozprowadzenia mieszaniny dymu w komorze wędzarniczej. Przeprowadzone w warunkach rzeczywistych badania z wykorzystaniem zmodyfikowanych dysz zasilających w porównaniu z klasycznym układem potwierdzają zależności uzyskane z symulacji.
This paper elaborates upon the use of Computational Fluid Dynamics (CFD) tools in the engineering practice as an integral part of progress of the chemical engineering of smoke-drying taking into consideration the technical progress and smoke-drying methods. The use of tools connected to CDF modeling allowed collecting crucial information concerning the performed process of smoke-drying for the assortment geometrically shaped similarly to a piece of oval ham. A single truck chamber was a base construction for solutions of the suggested modification of the powering elements (nozzles) as well as for the computer model geometry of the construction of an empty chamber and a full chamber itself. Discretization has been made in the ANSYS Mechanical APDL 12.1 software and on this basis a model of the suggested solution for construction of power nozzles as well as nozzles spreading the smoke substance inside the smoking chamber has been prepared. On the basis of simulating models and received feedback we can unequivocally say, that more advantageous conditions of spreading the smoke substance in the smoking chamber had been found. The tests performed in the real conditions with the use of modified power nozzles in comparison to the classical arrangement confirm dependences obtained during simulation.
Źródło:
Agricultural Engineering; 2014, 18, 1; 73-81
2083-1587
Pojawia się w:
Agricultural Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling of influence of turbulent transition on heat transfer conditions
Autorzy:
Bochon, K.
Wróblewski, W.
Dykas, S.
Powiązania:
https://bibliotekanauki.pl/articles/1943251.pdf
Data publikacji:
2008
Wydawca:
Politechnika Gdańska
Tematy:
laminar-turbulent transition
Conjugate Heat Transfer (CHT)
computational fluid dynamics CFD
Opis:
This article deals with the turbulent transition phenomenon modelling and its influence on heat transfer. The purpose of the analyses was to verify the transition modelling implemented in the ANSYS CFX 11 commercial code for popular test cases (low flow speed) described in literature, and then use it for verification of the in-house CFD code (created for compressible flows). The inhouse CFD code has been extended lately for the Conjugate Heat Transfer modelling (CHT) as well, taking into account important flow effects, especially the turbulent transition. A Wilcox k-omega turbulence model with the Low-Reynolds modification was used in the in-house code. The calculations in ANSYS CFX were made using an SST turbulence model and a gamma-theta transition model. A fully turbulent flow was modelled by means of both codes, and the results were compared with the available experimental data. Then, the turbulent transition for several test cases was analysed with ANSYS CFX. Afterwards, the in-house CFD code was verified by means of ANSYS CFX for a higher flow speed (Mach numbers). The CHT modelling was analysed by means of both codes and the results were compared and discussed. The conducted analyses show that the results obtained by means of both codes are comparable, but the turbulence model used in the in-house CFD code is simpler and requires less computation time. A modification of two equations turbulence models can be an alternative for design problems in more developed laminar/turbulent flows.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2008, 12, 3-4; 173-184
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Feasibility study of RANS in predicting propeller cavitation in behind-hull conditions
Autorzy:
Zhang, Yuxin
Wu, Xiao-ping
Lai, Ming-yan
Zhou, Guo-ping
Zhang, Jie
Powiązania:
https://bibliotekanauki.pl/articles/1573849.pdf
Data publikacji:
2020
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
RANS
Computational Fluid Dynamics (CFD)
propeller cavitation
turbulence model
grid sensitivity
Opis:
The propeller cavitation not only affects the propulsive efficiency of a ship but also can cause vibration and noise. Accurate predictions of propeller cavitation are crucial at the design stage. This paper investigates the feasibility of the Reynolds-averaged Navier–Stokes (RANS) method in predicting propeller cavitation in behind-hull conditions, focusing on four aspects: (i) grid sensitivity; (ii) the time step effect; (iii) the turbulence model effect; and (iv) ability to rank two slightly different propellers. The Schnerr-Sauer model is adopted as the cavitation model. A model test is conducted to validate the numerical results. Good agreement on the cavitation pattern is obtained between the model test and computational fluid dynamics. Two propellers are computed, which have similar geometry but slightly different pitch ratios. The results show that RANS is capable of correctly differentiating the cavitation patterns between the two propellers in terms of the occurrence of face cavitation and the extent of sheet cavitation; moreover, time step size is found to slightly affect sheet cavitation and has a significant impact on the survival of the tip vortex cavitation. It is also observed that grid refinement is crucial for capturing tip vortex cavitation and the two-equation turbulence models used – realizable k-ε and shear stress transport (SST) k-ω – yield similar cavitation results.
Źródło:
Polish Maritime Research; 2020, 4; 26-35
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Three - dimensional numerical simulations of the combustion chamber of the rotating detonation engine
Autorzy:
Folusiak, M.
Swiderski, K.
Kobiera, A.
Lukasik, B.
Wolanski, P.
Powiązania:
https://bibliotekanauki.pl/articles/245644.pdf
Data publikacji:
2013
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
rotating detonation engine (RDE)
RDE
computational fluid dynamics (CFD)
CFD
REFLOPS
Opis:
From 2010 Warsaw University of Technology (WUT) and Institute of Aviation (IoA) jointly implement the project under the Innovative Economy Operational Programme entitled ‘Turbine engine with detonation combustion chamber’. The goal of the project is to replace the combustion chamber of turboshaft engine GTD-350 with an annular detonation chamber. During the project, the numerical group that aims to develop computer code allowing researchers to simulate investigated processes has been established. Simulations provide wide range of parameters that are hardly available from experimental results and enable better understanding of investigated processes. Simulations may be also considered as a cheap alternative for experiments, especially when testing geometrical optimizations. In this paper the analysis of simulation results of the combustion chamber of the Rotating Detonation Engine (RDE) investigated at the IoA in Warsaw is presented. Primarily, REFLOPS USG which has become a fundamental numerical tool in the research of the RDE at the IoA is briefly described and governing equations and numerical methods used are shortly presented. Some aspects of numerical simulations of the RDE, related to selection of combustion mechanism, and an initiation of rotating detonation are provided. Secondly, results of simulations of inviscid gas with numerical injectors of hydrogen are compared with available experimental results. Three different wave patterns are identified in numerical solution and briefly described. Results of simulations are compared to experimental results in combustion chamber. Results presented in this paper are part of the project UDA-POIG.01.03.01-14-071 ‘Turbine engine with detonation combustion chamber’ supported by EU and Ministry of Regional Development, Poland.
Źródło:
Journal of KONES; 2013, 20, 1; 83-88
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical analysis of influence of ship hull form modification on ship resistance and propulsion characteristics. Part I. Influence of hull form modification on ship resistance characteristics
Autorzy:
Szelangiewicz, T.
Abramowski, T.
Powiązania:
https://bibliotekanauki.pl/articles/258900.pdf
Data publikacji:
2009
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
ship hull geometry
computational fluid dynamics (CFD)
resistance
wake
propeller efficiency
Opis:
After signing ship building contract shipyard’s design office orders performance of ship resistance and propulsion model tests aimed at, apart from resistance measurements, also determination of ship speed, propeller rotational speed and propulsion engine power for the designed ship, as well as improvement of its hull form, if necessary. Range of ship hull modifications is practically very limited due to cost and time reasons. Hence numerical methods, mainly CFD ones are more and more often used for such tests. In this paper consisted of 3 parts, are presented results of numerical calculations of hull resistance, wake and efficiency of propeller operating in non-homogenous velocity field, performed for research on 18 hull versions of B573 ship designed and built by Szczecin Nowa Shipyard.
Źródło:
Polish Maritime Research; 2009, 4; 3-8
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical analysis of influence of streamline rudder on screw propeller efficiency
Autorzy:
Abramowski, T.
Handke, J.
Szelangiewicz, T.
Powiązania:
https://bibliotekanauki.pl/articles/259235.pdf
Data publikacji:
2010
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
Streamline rudder, improvement of screw propeller efficiency
computational fluid dynamics (CFD)
Opis:
During designing the ship its designer tends to obtain as high as possible efficiency of ship propulsion system. To this end on certain ships additional elements such as: nozzles, half-nozzles or suitably profiled fins attached to underwater part of ship’s hull before screw propeller, are applied (sometimes they are intended for the mitigating of vibration resulting from operation of screw propeller). Another device which affects operation of screw propeller is streamline rudder capable of improving its efficiency (most of the transport ships is fitted with single screw propeller and streamline rudder placed behind it). In this paper the influence of streamline rudder on screw propeller efficiency has been examined with the use of numerical methods of fluid dynamics (CFD).The obtained results indicate a very favourable influence of the rudder on screw propeller efficiency. Research in this area is continued and its results concerning impact of particular geometrical parameters of rudder on screw propeller efficiency, will be presented in the future.
Źródło:
Polish Maritime Research; 2010, 2; 18-22
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A complete design of contra-rotating propellers using the new computer system
Autorzy:
Koronowicz, T.
Krzemianowski, Z.
Tuszkowska, T.
Szantyr, J. A.
Powiązania:
https://bibliotekanauki.pl/articles/259381.pdf
Data publikacji:
2010
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
ship propellers
contra-rotating propellers
esign methods
computational fluid dynamics (CFD)
Opis:
The computer system for the complete design of the contra-rotating propellers presented in this article has several common blocks and procedures with the systems for design of single propellers and tandem corotating propellers, presented in detail in the Polish Maritime Research No.1 and No.4 of the Volume 16, 2009. In this article only the blocks and procedures developed specially for the contra-rotating propellers are described. The system is based on the lifting line and lifting surface models and on the Computational Fluid Mechanics methods. The comparative analysis of the contra-rotating propellers and the tandem corotating propellers is included.
Źródło:
Polish Maritime Research; 2010, 1; 14-24
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-50 z 214

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