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Tytuł:
Numerical simulation of 3D flow in axial turbomachines
Autorzy:
Yershov, S.
Rusanov, A. V.
Gardzielewicz, A.
Lampart, P.
Świrdyczuk, J.
Powiązania:
https://bibliotekanauki.pl/articles/1953978.pdf
Data publikacji:
1998
Wydawca:
Politechnika Gdańska
Tematy:
numerical simulation
axial turbomachines
3D flow
3D viscous compressible flow
Navier-Stokes equation
ENO reconstruction
computational efficiency
computational fluid dynamics CFD
Godunov-type upwind differencing
Opis:
The paper is intended to describe a method for the calculation of 3D viscous compressible (subsonic or supersonic) flow in axial turbomachines described in the form of thin-layer Reynolds-averaged Navier-Stokes equations. The method draws on Godunov-type upwind differencing and ENO reconstruction suggested by Harten (1987), so as to assure monotonicity preservation and high accuracy of computational results. The computational efficiency is achieved thanks to the implementation of a simplified H-type multi-grid approach and delta -form implicit step. Turbulent effects are simulated with the help of a modified algebraic model of Baldwin-Lomax (1978). This method was at the foundation of a computer code-a complex software package to calculate 3D flow in multi-stage turbomachines that allows us to obtain local characteristics, like temperature, pressure, density or velocity distributions, as well as global characteristics, such as flow rates, stage reaction, flow efficiency for the considered turbine/compressor stage. The paper also gives selected results of computation of a number of turbomachinery cascades, showing that these results agree reasonably well with the available experimental data.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 1998, 2, 2; 319-347
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multiblock parallel computation of an incompressible 3D flow in turbomachines
Autorzy:
Papierski, A.
Rabiega, M.
Powiązania:
https://bibliotekanauki.pl/articles/1954540.pdf
Data publikacji:
1999
Wydawca:
Politechnika Gdańska
Tematy:
numerical simulations
turbomachinery
incompressible flow
3D Navier-Stockes solver
Navier-Stokes solver
parallel computing
Opis:
A finite volume numerical method for the prediction of a fluid flow in complex geometries such as turbomachinery channels has been parallelized using a domain decomposition approach. A mathematical formulation of a 3-D incompressible steady flow has been presented on the basis of the N-S equations in a grid-oriented co-ordinate system with contravariant velocity components. A parallelized pressure-based implicit algorithm with discretization on a staggered grid has been developed. A message exchange system with a boundary exchange, developed by the authors, has been described. Exemplary calculations have been carried out for a laminar flow through a curved duct and for an inviscid flow through a stage of the centrifugal pump. A good agreement has been obtained in both the cases. Despite considerable simplification that has been introduced in the flow through the pump stage, the computations have shown nearly the same pressure rise in the stage as the measurements. Further directions of numerical investigations of a flow through turbomachines, including in particular those devoted to pressure losses related to the rotor-stator interaction, have been mentioned.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 1999, 3, 1; 39-52
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The analysis of separation and methods of three-dimensional flow structure detection in the boundary layer shock wave interaction
Autorzy:
Czerwińska, J.
Powiązania:
https://bibliotekanauki.pl/articles/1954539.pdf
Data publikacji:
1999
Wydawca:
Politechnika Gdańska
Tematy:
shock wave boundary layer interaction
flow separation
3D flow structures
numerical simulations
Opis:
The normal shock wave turbulent boundary layer interaction still draws a great deal of attention as a flow phenomenon. This is due to its profound importance to numerous applications. The understanding of phenomena is crucial for future aims connected with the interaction control. Experimental investigations of the interaction have been carried out since the 1940s. They were aimed however at the determination of such general flow features as: pressure distribution, shock wave configuration or oil visualization of separation structures. In order to better understand the phenomenon, measurements of the entire field are required. At present, such measurements do not exist. A great help is expected from numerical simulations in this respect. There is enough experimental data to check the general features of the flow obtained from calculations. This thesis presents numerical simulations of flow that is assumed: steady, three-dimensional, compressible, viscous and turbulent. Its general aim is to present to what extend the modern numerical methods are able to predict the flow in shock wave turbulent boundary layer interaction including shock induced separation structures. These structures are very sensitive to channel geometry and may be useful in the understanding of separation's development. In order to illustrate the abilities of numerical simulations, one aim of the presented thesis is to investigate the effect of the span-wise depth of the nominally two-dimensional test section. The presented results cast some light on the common problems experienced by typical comparisons of two-dimensional simulations to wind tunnel tests having a three-dimensional nature. The first Chapter presents the basic theory of elementary structures. Considerations of elementary structures of the flow along with their dependencies are necessary for a better understanding of the separation flow structures induced by the boundary layer shock wave interaction. The classification of elementary structures will be presented. In addition, the possible occurrence of bifurcation will also be studied. The second Chapter will be devoted to studying specific cases of transonic turbulent flow. The analysis of numerical results will be bounded to the shock wave structure. Studies shall include: the influence of the numerical scheme, three-dimensional effects connected with the changing width of the channel, a comparison to experiment and the influence of the symmetric boundary condition on the flow prediction in the channel. Finally, the boundary layer influence on the 1-foot structure will also be presented. Chapter three will present the separation structures. Here too a comparison to experiments will be done. Changes in separation structures connected with the width of the channel will be studied. The influence of the symmetry boundary condition will be shown. Finally, the specification of the basic flow structures will be done.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 1999, 3, 1; 53-140
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical simulation and modification of 3D flow phenomena in an axial flow fan
Autorzy:
Elhadi, E. E.
Keqi, W.
Powiązania:
https://bibliotekanauki.pl/articles/1954658.pdf
Data publikacji:
2003
Wydawca:
Politechnika Gdańska
Tematy:
axial flow fan
vortex
stagger angle
numerical simulation
3D
Opis:
This work aims to study and analyze the behavior of flow in an axial flow fan using numerical simulation based on solving Reynolds-averaged Navier-Stokes equations coupled with a modified Spalart-Allaras turbulence model. In the present work, different flow phenomena occuring in an axial flow fan were presented and interpreted at different design conditions and at different regions, with special concern to the rotor exit and stator regions. Large vortices and reverse flow at the stator suction side were observed under high loading conditions. These are mainly due to radial and centrifugal effects in the fluid due to a decreasing flow rate. To avoid this type of flow, the stator flow pattern has been modified using a new stator blade. This blade was designed by changing the stator stagger angle by 10o in the radial direction. This study indicates that the flow in the modified stator region behaves well and gives better performance than that obtained when using a baseline stator, especially under high loading conditions. This study also indicates that the stator stagger angle has a significant effect on modifying the fan performance.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2003, 7, 2; 199-213
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A turbulence model for 3-d flows with anisotropic structure of turbulence
Autorzy:
Czernuszenko, W.
Rylov, A.
Powiązania:
https://bibliotekanauki.pl/articles/241364.pdf
Data publikacji:
2005
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
3D flow
mathematical model
numerical simulation
open channel flow
turbulence model
Opis:
A new turbulence model for flows in open channels with compound cross-sections is presented. The structure of turbulence in these channels can be anisotropic. This structure is described by the turbulent stress tensor that is presented here as the sum of two tensors, namely, normal and shear stress tensors. The normal and shear turbulent stresses are expressed by the turbulence intensities and the mixing length tensor (MLT), respectively. The turbulence intensities can be learned from measurements or another suitable approaches. One such approach that allows calculating the main component of the normal stresses is presented in the paper. The components of MLT are defined based on a new concept of generic mixing length (GML). The generic mixing length is assumed to depend on both distances; from the nearest wall and from the water surface. To demonstrate how the new model works the basic hydrodynamic equations (parabolic approximation of Reynolds equations) together with the turbulence model are solved. The well-known Patankar and Spalding (1972) algorithm was used when solving these equations. A series of numerical simulations were performed for different components of MLT and different channel geometries.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2005, 52, 4; 303-320
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza pola prędkości w wyrobiskach przewietrzanych przez dyfuzję
Airflow patterns inside a short blind heading
Autorzy:
Branny, M.
Filipek, W.
Karch, M.
Powiązania:
https://bibliotekanauki.pl/articles/350184.pdf
Data publikacji:
2010
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
wentylacja przez dyfuzję
3D symulacja przepływów
metody CFD
ventilation of blind headings
3D flow fields simulation
CFD methods
Opis:
Rozważa się proces przewietrzania krótkiego wyrobiska ślepego realizowany wyłącznie pod wpływem działania wentylatorów głównych. Analizowano obrazy pól prędkości w komorze przy różnych prędkościach przepływu w opływowym prądzie powietrza wynoszących od 0,65 m/s do 2,1 m/s. Obliczenia 3D pól prędkości wykonano przy użyciu metod CFD. Testowano dwa modele turbulencji: standardowy k- i RNG k- oraz dwa sposoby opisu warunków brzegowych: przy pomocy funkcji ściany oraz stosując dwuwarstwowy model warstwy przyściennej. Wyniki obliczeń numerycznych porównywano z pomiarami.
Ventilation of short blind heading caused by through road air velocity is considered. A series of numerical tests was performed to determine the effect of different through air velocities on airflow patterns. The velocities ranged between 0,65 m/s and 2,1 m/s. 3D velocity fields was calculated using a finite-volume CFD computer code FLUENT 6.1. Two turbulence models (standard k- and RNG k-) as well as two near-wall models (wall function and enhanced wall treating) were tested. Numerical results were compared with experimental data.
Źródło:
Górnictwo i Geoinżynieria; 2010, 34, 1; 41-51
1732-6702
Pojawia się w:
Górnictwo i Geoinżynieria
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Biolex Beta-HP on phagocytic activity and oxidative metabolism of peripherial blood granulocytes and monocytes in rats intoxicated by cyclophosphamide
Autorzy:
Wojcik, R
Powiązania:
https://bibliotekanauki.pl/articles/32265.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
beta-1,3-1,6-D-glucan
cyclophosphamide
rat
phagocytic activity
oxidative metabolism
granulocyte
monocyte
flow cytometry
peripheral blood
immunosuppression
blood neutrophil
Opis:
The objective of this study was to determine the effect of ß-l,3/l,6-D-glucan (Biolex-Beta HP) on the phagocytic activity and oxidative metabolism of peripheral blood granulocytes and monocytes in rats intoxicated by cyclophosphamide. The experimental material comprised 40 adult Wistar rats aged 14 weeks, divided into two equal groups, a control group and an experimental group, each of 20 adult rats, including 10 males and 10 females. In the course of 3 successive days, 20 rats from the experimental group were administered cyclophosphamide intramuscularly at a dose of 50 mg/kg body weight/day. On the 8th day of the experiment, 10 control group (K) rats and 10 experimental group (C) rats were sacrificed. Arterial blood samples were collected and diluted with heparin to determine and compare the phagocytic activity (Phatogest) and oxidative metabolism (Bursttest) of peripheral blood granulocytes and monocytes by flow cytometry. Starting on the 8lh day of the experiment, the feed of the remaining 10 rats from the experimental group (C+G) and 10 rats from the control group (G) was supplemented with Biolex-Beta HP at a dose of 50 mg/kg body weight/day for 14 consecutive days. On day 22, arterial blood samples were collected from all (C+G) and (C) group rats, diluted with heparin to determine and compare the phagocytic activity and oxidative metabolism of peripheral blood granulocytes and monocytes by flow cytometry. The results showed that Biolex-Beta HP modulated the phagocytic activity and oxidative metabolism of blood neutrophils and monocytes suppressed by cyclophosphamide in rats. The immunorestoring activity of Biolex-Beta HP was observed in this study.
Źródło:
Polish Journal of Veterinary Sciences; 2010, 13, 1; 181-188
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design Model and Data Management for 3D IC Development
Autorzy:
Grunewald, W.
Hahn, K.
Bruck, R.
Powiązania:
https://bibliotekanauki.pl/articles/398005.pdf
Data publikacji:
2012
Wydawca:
Politechnika Łódzka. Wydział Mikroelektroniki i Informatyki
Tematy:
integracja 3D
zarządzanie danymi
projekt modelu
przebieg procesu
3D integration
data management
design model
process flow
Opis:
The development of 3D systems is a highly complex procedure. Next to a huge variation of possibilities on how to vertically integrate two or more dies, a lot of aspects regarding cost, design and application specific selection of technology have to be considered. Therefore a design model will be presented, that considers the mutual influence of design and process technology during the integration flow development. The design model has been implemented in a software system. To be able to develop integration flows, complex technology information is needed, which results in the necessity of a data management with usage of a technology database.
Źródło:
International Journal of Microelectronics and Computer Science; 2012, 3, 3; 88-94
2080-8755
2353-9607
Pojawia się w:
International Journal of Microelectronics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical Analysis of Solid Particles Flow in Liquid Metal
Autorzy:
Szucki, M.
Goraj, T.
Lelito, J.
Suchy, J. S.
Powiązania:
https://bibliotekanauki.pl/articles/382986.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
numerical analysis
solid particle
particle flow
metal matrix composite
FLOW-3D software
analiza numeryczna
cząstka stała
przepływ cząstki
kompozyt metalowy
oprogramowanie FLOW-3D
Opis:
The aim of the study was to determine the influence of the solid particles density and size on their distribution in the solidified cast. As part of the work, a series of numerical simulations of filling and solidification process were made with the use of FLOW-3D software. The analysis was performed on pure aluminum and six chosen types of particles with different size and density. Obtained results may help to understand the behavior of solid particles in liquid metals.
Źródło:
Archives of Foundry Engineering; 2013, 13, 3 spec.; 161-166
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical Studies on a Three-dimensional Flow Field in Four-Roller Compact Spinning with a Guiding Device
Badania numeryczne trójwymiarowego pola przepływu w czterowałkowym aparacie rozciągowym przędzarki kompaktowej wyposażonej w urządzenie prowadzące
Autorzy:
Liu, X.
Xie, C.
Su, X.
Mei, H.
Powiązania:
https://bibliotekanauki.pl/articles/233593.pdf
Data publikacji:
2013
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
four-roller compact spinning
guiding device
3D flow field
numerical simulation
fluent
kompaktowy układ czterorolkowy
urządzenie prowadzące
pole przepływu 3D
symulacja numeryczna
analiza pola przepływu
Opis:
Research on the flow field in the fibre-converging zone is always the emphasis and difficulty of compact spinning. Therefore in this work numerical studies on the three-dimensional flow field in four-roller compact spinning with a guiding device were carried out using Fluent software. First a three-dimensional physical model of the fibre-converging zone was obtained using AutoCAD software. Then numerical simulations of the three-dimensional flow field in four-roller compact spinning with and without a guiding device were presented, respectively, using Fluent software. It was shown that the negative pressure is chiefly concentrated near the air-suction flume, and the velocity reaches the maximum on the centre line. Comparing with the flow field in compact spinning without a guiding device, the effective range of negative pressure in four-roller compact spinning with a guiding device increases significantly and negative pressure use efficiency improves accordingly. Furthermore the optimal installation position of the guiding device was studied, and it was shown that the optimal installation position is closely related to the linear density of the spun yarn. Finally the theoretical results obtained were illustrated by experiments.
Podstawową trudnością w przędzeniu kompaktowym jest analiza pola przepływu strumienia włókien, którą przeprowadzono korzystając ze specjalnego oprogramowania – Fluent Software. Wstępnie opracowano model fizyczny procesu korzystając z systemu AutoCAD. Wykazano, że podciśnienie jest głównie skoncentrowane w pobliżu kanałów zasysających i prędkość osiąga swoje maksimum w centrum układu. Wykazano korzyści z zastosowania układu czterorolkowego w porównaniu do układu klasycznego i optymalne pozycje rozmieszczenia ściśle uzależnione od masy liniowej produkowanej przędzy. Uzyskane obliczenia teoretyczne porównano z wynikami praktycznymi.
Źródło:
Fibres & Textiles in Eastern Europe; 2013, 6 (102); 50-57
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Use of information bases for the application of operational aviation regulations
Autorzy:
Šála, J.
Němec, V.
Novák, A.
Powiązania:
https://bibliotekanauki.pl/articles/393529.pdf
Data publikacji:
2013
Wydawca:
Polskie Stowarzyszenie Telematyki Transportu
Tematy:
3D modelling
traffic flow
electronic regulation
information basis
modelowanie 3D
przepływ ruchu
regulacja elektroniczna
baza informacyjna
Opis:
Text of the article describes the application of information bases as a tool for safety in air transport. By converting these rules into the base allows easier and quicker orientation in regulatory requirements. The following paragraphs provide information about the whole concept and demonstrate key concepts needed to understand the software.
Źródło:
Archives of Transport System Telematics; 2013, 6, 4; 42-45
1899-8208
Pojawia się w:
Archives of Transport System Telematics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numeryczna analiza przepływów w wybranych fragmentach układów wlewowych stosowanych przy wytwarzaniu odlewów wielkogabarytowych
Numerical Analysis of Flows in Selected Parts of the Gating Systems Used in Large-size Castings Production
Autorzy:
Goraj, T.
Szucki, M.
Lelito, J.
Suchy, J. S.
Powiązania:
https://bibliotekanauki.pl/articles/380475.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
analiza numeryczna
układy wlewowe
odlewy wielkogabarytowe
pęcherze gazowe
FLOW-3D
numerical analysis
large-size castings
filling system
Opis:
Niniejsza praca zawiera analizę przepływów dwufazowych (ciekły metal - gaz) w wybranym fragmencie układów wlewowych, stosowanych przy produkcji wielkogabarytowych odlewów ze stopów żelaza, w oparciu o symulacje komputerowe wykonane w programie FLOW-3D. W ramach publikacji dobrano układy modelowe oraz parametry symulacji numerycznych. Na podstawie uzyskanych wyników badań szczegółowo przestudiowano rozkład prędkości i ciśnienia w tych układach oraz wskazano obszary narażone na erozję materiału ceramicznego i miejsca kumulowania się gazów.
Current work includes an analysis of the two-phase flows (liquid metal - gas) in a selected parts of the gating systems, used in large-size iron castings production. The studies were carried out with the use of FLOW-3D software. Within the paper a model system and the parameters of numerical simulations were selected. Based on the obtained results, the velocity and pressure profile in the model systems were analyzed as well as the areas susceptible to erosion of the ceramic material and gas entrainment were indicated.
Źródło:
Archives of Foundry Engineering; 2014, 14, 4 spec.; 25-30
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Doświadczalna weryfikacja symulacji procesu odlewania odśrodkowego w formach ceramicznych
Experimental verification of the simulation of centrifugal casting in ceramic moulds
Autorzy:
Leśniewski, W.
Wieliczko, P.
Małysza, M.
Powiązania:
https://bibliotekanauki.pl/articles/391743.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Odlewnictwa
Tematy:
odlewanie odśrodkowe
symulacja komputerowa
Flow-3D
modele woskowe
siła odśrodkowa
siła Coriolisa
centrifugal casting
computer simulation
wax models
centrifugal force
Coriolis force
Opis:
W artykule przedstawiono wyniki prac związanych z ustaleniem rzeczywistego przepływu ciekłego metalu w formie podczas procesu odlewania odśrodkowego w indukcyjnym piecu próżniowym firmy SuperCast Linn HighTherm. W procesie odlewania odśrodkowego wykorzystywany jest wpływ siły odśrodkowej na przepływ ciekłego metalu w formie, a następnie powodowany nią wzrost ciśnienia ciekłego – krzepnącego metalu. Dla prędkości wirowania formy równej 250 rpm i odległości formy wynoszącej 0,2 m od osi obrotu wartość siły odśrodkowej działającej na ciekły metal jest 14 razy większa od siły grawitacji. Mimo tak dużej siły często obserwowano w odlewach wykonanych w indukcyjnych piecach odśrodkowych niedolewy, których przyczyny były niewyjaśnione. Działająca w tym przypadku siła grawitacji nie ma istotnego znaczenia na przepływ metalu w wirującej formie. Podczas wykonywania odlewów w piecu odśrodkowym na powierzchni tygla pozostaje pewna ilość metalu wskazująca, że podczas odlewania na ciekły metal muszą oddziaływać minimum dwie siły. Jedną z nich jest siła odśrodkowa wymuszająca przepływ metalu równolegle do promienia wodzącego wirującej formy. Zwrot drugiej siły jest skierowany prostopadle do kierunku promienia wodzącego, na co wskazuje pozostałość zakrzepniętego metalu w kanale wylewowym tygla. Wykorzystując specjalnie dobraną geometrię zestawu odlewniczego, przeprowadzono serię doświadczeń, umożliwiającą zaobserwowanie sposobu przepływu i wypełniania formy. Analiza uzyskanych wyników wskazuje, że podczas symulacji komputerowej prowadzonej w nieinercjalnych układach odniesienia uwzględnienie siły Coriolisa wyjaśnia przepływ metalu podczas odśrodkowego zalewania formy. Przeprowadzone obliczenia komputerowe potwierdziły zgodność z wynikami przeprowadzonych doświadczeń.
This paper presents the results of work on the determination of actual molten metal flow in a mould during centrifugal casting in the SuperCast induction vacuum furnace manufactured by Linn HighTherm. The centrifugal casting process uses the effect of centrifugal force on the flow of liquid metal in the mould with a resulting increase of the liquid and solidifying metal pressure. At the mould rotational speed of 250 rpm and the mould distance of 0.2 m from the rotation axis, the centrifugal force acting on the liquid metal is 14 times higher than the force of gravity. Despite a high force, misruns of unexplained origin have been found in castings from centrifugal induction furnaces. Here the action of gravity is insignificant to the flow of metal within the rotating mould. When casting in centrifugal forces, a certain amount of metal remains on the crucible surface, indicative of a minimum two forces present and acting on the liquid metal during the process. One is the centrifugal force, which prompts the flow of metal in parallel to the radius vector of the rotating mould. The sense of the other force is directed perpendicularly to the radius vector direction, as suggested by the residues of solidified metal in the crucible spout. A specially designed geometry of the casting system has been used in a series of experiments to observe the way in which the flow and casting filling occur. The analysis of produced results suggests that the inclusion of the Coriolis force in the computer-aided simulation of non-inertial reference systems explains the metal flow during centrifugal pouring. The computer calculations have proven the results of the said experiments.
Źródło:
Prace Instytutu Odlewnictwa; 2015, T. 55, nr 1, 1; 23-29
1899-2439
Pojawia się w:
Prace Instytutu Odlewnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental and computational studies of stall on a helicopter rotor airfoil
Autorzy:
Surmacz, K.
Powiązania:
https://bibliotekanauki.pl/articles/246413.pdf
Data publikacji:
2016
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
3D flow
CFD
wind tunnel test
oil visualization
stall phenomenon
Opis:
In the case of forward flight of a helicopter, the flow field around rotating blades of a rotor is highly threedimensional and very complex. Helicopter blades work across a wide range of angles of attack and airspeed. The stall occurs on the retreating blade in forward flight and causes dissymmetry of lift on a rotor disc. The investigation of the stall phenomenon has been performed using experimental and computational methods. Experimental analysis was made at the Ohio State University 6’’x 22’’ unsteady transonic wind tunnel. Research in the wind tunnel was performed using two methods: oil visualization (over a wide range of alpha and Ma) and pressure measurements. Computational part of the research has been done using Computational Fluid Dynamics tool. 2- and 3-dimensional calculations performed using ANSYS FLUENT software. In both experimental and computational cases, the 3D flow around a section of a rotor blade based on the SSC-A09 airfoil was analysed. The test article of the research was a section, which was located in the tip region of the main rotor blade of UH-60M Black Hawk helicopter. The research was conducted for a wide range of angles of attack and at several velocities. The most interesting part of the analysis concerned on unsteady flow conditions corresponding to stall.
Źródło:
Journal of KONES; 2016, 23, 3; 511-517
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical simulation of 3D flow in VKI-Genoa turbine cascade including laminar-turbulent transition
Autorzy:
Yerschov, S.
Derevyanko, A.
Yakovlev, V.
Gryzun, M.
Powiązania:
https://bibliotekanauki.pl/articles/1938601.pdf
Data publikacji:
2016
Wydawca:
Politechnika Gdańska
Tematy:
numerical simulation
3D flow
turbine cascade
laminar-turbulent transition
turbulence kinetic energy
secondary flows
losses
Opis:
This study presents a numerical simulation of a 3D viscous flow in the VKI-Genoa cascade taking into account the laminar-turbulent transition. The numerical simulation is performed using the Reynolds-averaged Navier-Stokes equations and the two-equation k-ω SST turbulence model. The algebraic Production Term Modification model is used for modeling the laminar-turbulent transition. Computations of both fully turbulent and transitional flows are carried out. The Mach number contours, the turbulence kinetic energy, the entropy function as well as the limiting streamlines are presented. Our numerical results demonstrate the influence of the laminar-turbulent transition on the secondary flow pattern. The comparison between the present computational results and the existing experimental and numerical data shows that the proposed approach reflects sufficiently the physics of the laminar-turbulent transition in turbine cascades.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2016, 20, 1; 43-61
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 24

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