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Wyszukujesz frazę "Szulc, O." wg kryterium: Wszystkie pola


Tytuł:
Rotorcraft thickness noise control
Autorzy:
Szulc, O.
Powiązania:
https://bibliotekanauki.pl/articles/38627396.pdf
Data publikacji:
2021
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
helicopter rotor
aerodynamics
aeroacoustics
CFD
noise reduction
active flow
noise control
surface transpiration
perforation
Opis:
The paper describes an innovative idea of Thickness Noise Control (TNC) based on adoption of a flow control strategy (i.e. surface ventilation) for acoustic attenuation of helicopter rotor periodic noise. The TNC method is relying on incorporation of multiple cavities (closed by perforated panels and linked to low- and high-pressure reservoirs) located in a symmetrical manner at front and rear portions of the blade tip. The efficiency of the new approach is verified using a two-bladed model rotor of Purcell (untwisted variant of the blade of Bell UH-1H Iroquois helicopter) in low-thrust hover conditions. The results of numerical simulations, obtained with CFD solver (Spalart–Allmaras turbulence and Bohning–Doerffer transpiration models), indicate that in the near-field of the blade tip, both the amplitude and spectral contents of pressure impulses of emitted thickness noise are significantly improved. The TNC method, in the proposed unsteady mode of operation, turns out to be a suitable means of thickness noise reduction in forward flight. Moreover, it is demonstrated that by proper azimuthal activation the efficiency is almost unaltered, while the rotor torque penalty and required transpiration mass-flux are decreased by a factor of 3–5 compared to a steady arrangement.
Źródło:
Archives of Mechanics; 2021, 73, 4; 391-417
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical simulation of model helicopter rotor in hover
Autorzy:
Doerffer, P.
Szulc, O.
Powiązania:
https://bibliotekanauki.pl/articles/1943245.pdf
Data publikacji:
2008
Wydawca:
Politechnika Gdańska
Tematy:
transonic
hover
helicopter rotor
Opis:
The article presents details of a URANS simulation of the flow field near a hovering model of the Caradonna and Tung (1981) helicopter rotor [1]. The CFD code SPARC [2] proves to be capable of capturing the aerodynamics of a two-bladed rotor in high-speed transonic hover conditions. A comparison of the simulation results with the experimental data is acceptable, hence the described methodology might be used with confidence in future numerical studies of application of noise-reducing devices on helicopter blades.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2008, 12, 3-4; 227-236
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High-lift behaviour of half-models at flight Reynolds numbers
Autorzy:
Szulc, O.
Doerffer, P.
Powiązania:
https://bibliotekanauki.pl/articles/1955212.pdf
Data publikacji:
2006
Wydawca:
Politechnika Gdańska
Tematy:
half-span
wing-body
high-lift
peniche
Navier-Stokes
Opis:
A peniche is designed to offset a half-span aircraft model from the wind tunnel wall boundary layer. This strategy of model mounting results in large influence on the meas-ured aerodynamic coefficients, compared with full-span data, The negative influence is especially important in high-lift conditions leading to incorrect maximum lift behaviour, A very time-consuming set of python scripts was constructed to allow automatic meshing of the wing-body configuration of the DLR F11 high-lift model placed in the European Transonic Wind tunnel (ETW, Germany). Variations due to different concepts of model mountings (peniches) were included. A block-structured FLOWer solver (DLR, Germany) was used for all flow simulations, simplifying the mesh generation process by using the chimera overlapping grids technique, Preliminary results are available for a full-span configuration obtained with a symmetry condition at the mirror plane. Computations of the half-span model placed directly at the wall or mounted using a standard peniche are also presented.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2006, 10, 2; 191-206
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Passive control of shock wave applied to helicopter rotor high-speed impulsive noise reduction
Autorzy:
Doerffer, P.
Szulc, O.
Powiązania:
https://bibliotekanauki.pl/articles/1943208.pdf
Data publikacji:
2010
Wydawca:
Politechnika Gdańska
Tematy:
shock wave
passive control
perforated wall
transpiration
helicopter rotor in hover
high-speed impulsive noise
Opis:
A strong, normal shock wave, terminating a local supersonic area on an airfoil (or a helicopter blade), not only limits the aerodynamic performance, but also becomes a source of High-Speed Impulsive (HSI) noise. The application of a passive control system (a cavity covered by a perforated plate) on a rotor blade should reduce the noise created by the moving shock. This article describes numerical investigations focused on the application of a passive control device on a helicopter blade in high-speed transonic hover conditions to weaken the shock wave – the main source of HSI noise.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2010, 14, 3; 297-305
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Shock wave induced flow separation control by Air-Jet and Rod Vortex Generators
Autorzy:
Tejero, F.
Doerffer, P.
Szulc, O.
Powiązania:
https://bibliotekanauki.pl/articles/1938633.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska
Tematy:
airfoil
boundary layer
flow control
separation
shock wave
transonic conditions
vortex generator
Opis:
Flow separation control by Vortex Generators (VGs) has been analyzed over the last decades. The majority of the research concerning this technology has been focused on subsonic flows where its effectiveness for separation reduction has been proven. Less complex configurations should be analyzed as a first step to apply VGs in transonic conditions, commonly present in many aviation applications. Therefore, the numerical investigation was carried out for a Shock Wave-Boundary-Layer Interaction (SWBLI) phenomenon inducing strong flow separation at the suction side of the NACA 0012 profile. For this purpose, two kinds of VGs were analyzed: well documented Air-Jet Vortex Generators (AJVGs) and our own invention of Rod Vortex Generators (RVGs). The results of the numerical simulations based on the RANS approach reveal a large potential of this passive flow control system in delaying stall and limiting separation induced by a strong, normal shock wave terminating a local supersonic area.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2015, 19, 2; 167-180
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Aeroacoustic analysis based on FW–H analogy to predict low-frequency in-plane harmonic noise of a helicopter rotor in hover
Autorzy:
Suresh, T.
Szulc, O.
Flaszynski, P.
Powiązania:
https://bibliotekanauki.pl/articles/38695686.pdf
Data publikacji:
2022
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
Lighthill’s analogy
Farassat’s formulation
blade element momentum theory
computational aeroacoustics
computational fluid dynamics
thickness noise
monopole
loading noise
dipole
Opis:
The integral formulation of the Ffowcs-Williams and Hawkings (FW–H) analogy, developed by Farassat (known as Farassat’s formulation 1A), is implemented to study the sound generation and propagation of rotating slender bodies. The general post-processing numerical code utilizes the linear acoustic theory to predict the thickness and loading noise terms for bodies in subsonic motion. The developed numerical code is validated for elementary acoustic sources (rotating monopole and dipole) against analytical solutions. The validated code is then applied for prediction of lowfrequency in-plane harmonic noise (LF-IPH) of a model helicopter rotor of Sargent and Schmitz in a low-thrust hover with full-scale tip Mach number. The required loading distribution of the rotor blade is obtained with CFD (RANS) and Blade Element Momentum Theory (BEMT) methods and also validated against literature data. The developed acoustic code, supplemented by CFD and BEMT loading analyses, allows for a detailed comparison (thickness and loading, near- and far-field, etc.) of the LFIPH noise of a helicopter rotor in both, time and frequency domains. The predicted (FW–H) acoustic signals are compared not only with the reference code solutions, but also with the experimental data. Moreover, the paper quantifies the impact of computational grid density and time-step size (used by CFD and FW–H codes) on the final solution accuracy. Additionally, a simplified analytical code is developed (based on elementary dipole solutions, compact chord assumption and BEMT method) allowing for the initial loading noise analysis with highly reduced computational resources. The acquired results are fully compatible with the classical FW–H analysis in terms of the impact of the in-plane and out-of-plane forces on the generated noise. The FW–H code predictions of the acoustic pressure and its components are in satisfactory agreement with the reference and experimental data of Sargent and Schmitz.
Źródło:
Archives of Mechanics; 2022, 74, 2-3; 201-246
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Unsteady Shock Wave: Turbulent boundary layer interaction in the Laval Nozzle
Autorzy:
Doerffer, P.
Szulc, O.
Magagnato, F.
Powiązania:
https://bibliotekanauki.pl/articles/1965143.pdf
Data publikacji:
2005
Wydawca:
Politechnika Gdańska
Tematy:
unsteady transonic flow
shock waves
nozzle flow
Opis:
The flow in transonic diffusers and supersonic air intakes often becomes unsteady due to shock wave-boundary layer interaction. Oscillations may be induced by natural separation unsteadiness or forced by boundary conditions. Significant improvements of CFD tools, increased computer resources and the development of experimental methods have again drawn the attention of researchers to this topic. Forced oscillations of a transonic turbulent flow in an asymmetric two-dimensional Laval nozzle have been considered to investigate the problem. A viscous, perfect gas flow was numerically simulated using SPARC, a Reynolds-averaged compressible Navier-Stokes solver, employing a two-equation, eddy viscosity, turbulence closure in the URANS approach. For time-dependent and stationary flow simulations, Mach numbers upstream of the shock between 1.2 and 1.4 were considered. Comparison of computed and experimental data for steady states generally gave acceptable agreement. In the case of forced oscillations, a harmonic pressure variation was prescribed at the exit plane resulting in shock wave motion. Excitation frequencies between 0Hz and 1024Hz were investigated at a constant pressure amplitude. The main result of the work is the relation between the amplitude of shock wave motion and the excitation frequency in the investigated range. Increasing excitation frequency resulted in decreasing amplitude of the shock movement. At high frequencies, a natural mode of shock oscillation (of small amplitude) was observed, which was insensitive to forced excitement.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2005, 9, 1; 115-132
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Time-accurate simulation of flow past PZL W-3A "Sokół" (Falcon) helicopter main rotor in forward flight
Autorzy:
Szulc, O.
Doerffer, P.
Żółtak, J.
Małecki, J.
Powiązania:
https://bibliotekanauki.pl/articles/1933943.pdf
Data publikacji:
2013
Wydawca:
Politechnika Gdańska
Tematy:
helicopter rotor
forward flight
chimera overlapping grid
Opis:
The paper presents the results of numerical simulations based on the URANS approach and the chimera overlapping grids technique of the main PZL W-3A "Sokół" (Falcon) helicopter rotor in forward flight conditions. The low-speed flight case models the helicopter rotor as parallel to the ground keeping forward speed of approximately 99km/h. Strong Blade-Vortex Interaction (BVI) is responsible for a high level of vibration and noise. The high-speed (266km/h) case reveals two main problems of modern helicopters: compressibility effects due to strong shock-wave boundary layer interaction on the advancing side and separation leading to a dynamic stall on the retreating side of the rotor. An attempt is made to correlate the results of the simulations with the very limited flight test data.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2013, 17, 1-2; 43-61
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Aerodynamic analysis of wind turbine rotor blades
Autorzy:
Martinez, J.
Doerffer, P.
Szulc, O.
Tejero, F.
Powiązania:
https://bibliotekanauki.pl/articles/1938637.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska
Tematy:
aerodynamics
CFD
NREL Phase VI rotor
wind turbine
Opis:
One of the main achievements of the PLGrid Plus project is the implementation of new tools and services designed for the numerical prediction of the aerodynamic performance of wind energy turbines. An innovative and unique integration tool (Aero-T) is aiming at automating all stages (pre-, solution and post-processing) of the numerical simulation of the flow around wind turbine rotor blades using commercial CFD software based on the RANS approach and block-structured computational grids. The FINE/Turbo package (Numeca Int.) is applied in the structured grid generation process and solution phases, while the analysis of results is left to the Tecplot 360 (Tecplot Inc.) software. A demonstrator based on the NREL Phase VI rotor experiment (conducted at NASA Ames) is introduced to prove the excellent prediction capabilities of Aero-T.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2015, 19, 2; 129-140
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical analysis of high-speed impulsive (HSI) noise of PZL W3-A "Sokół" (Falcon) helicopter main rotor in forward flight
Autorzy:
Szulc, O.
Doerffer, P.
Tejero, F.
Żółtak, J.
Małecki, J.
Powiązania:
https://bibliotekanauki.pl/articles/1938632.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska
Tematy:
aerodynamics
CFD
forward flight
helicopter rotor
HSI noise
shock wave
Opis:
The paper presents the results of a numerical simulation of the flow and acoustic field generated by the PZL W3-A “Sokół” (Falcon) helicopter main roto in high-speed forward flight conditions based on the URANS approach and the chimera overlapping grids technique. A refined CFD model (40+ million of control volumes, 600+ blocks chimera mesh) was designed to resolve the flow-field together with the low-frequency content of the acoustic pressure spectrum in the near-field of the rotor blades to allow high-speed impulsive (HSI) noise prediction. Detailed 3D data was recorded for one rotor revolution (approx. 3 TB) allowing exceptional insight into the physical mechanisms initiating the occurrence and development of the HSI noise phenomenon.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2015, 19, 2; 181-196
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Piotr Szulc, Decyzja o warunkach zabudowy. Studium z zakresu prawa administracyjnego, seria Monografie Prawnicze, Wydawnictwo C.H. Beck, Warszawa 2022, ss. 192, ISBN 978-83-8235-397-6
Piotr Szulc, The zoning decision. A study in administrative law [Decyzja o warunkach zabudowy. Studium z zakresu prawa administracyjnego], series Monografie Prawnicze, Wydawnictwo C.H. Beck, Warszawa 2022
Autorzy:
Jachimowicz-Jankowska, Paulina
Powiązania:
https://bibliotekanauki.pl/articles/28409218.pdf
Data publikacji:
2022
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Źródło:
Studia Prawa Publicznego; 2022, 3 (39); 191-198
2300-3936
Pojawia się w:
Studia Prawa Publicznego
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Poety życie podróżne – o dziennikach i zapiskach podróżnych Józefa Barana
Autorzy:
Szulc, Stefan
Powiązania:
https://bibliotekanauki.pl/articles/650221.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Opis:
The author of the essay describes the major motifs in the text of the diaries and travel notes by Józef Baran. He points out the kind of sensitivity and manners of imaging which are realized in the entire writing of the poet. He discusses the silva-rerum character of these notes, referring to the poetics of “confession” as described in the Pakt autobiograficzny by M. Czermińska, and pays attention to the issue of presence of other people in the autobiographic space.
Źródło:
Konteksty Kultury; 2013, 10, 1-2
2353-1991
Pojawia się w:
Konteksty Kultury
Dostawca treści:
Biblioteka Nauki
Artykuł

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