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Wyszukujesz frazę "Navier–Stokes equation" wg kryterium: Temat


Wyświetlanie 1-24 z 24
Tytuł:
Survey of applications of discrete vortex method in civil engineering
Autorzy:
Nowicki, T.
Powiązania:
https://bibliotekanauki.pl/articles/390713.pdf
Data publikacji:
2009
Wydawca:
Politechnika Lubelska. Wydawnictwo Politechniki Lubelskiej
Tematy:
discrete vortex method
Navier-Stokes equation
Opis:
This paper includes an introduction to Discrete Vortex Method (DVM) and its comparison with other methods of computer fluid dynamics. In its second part it focuses on the most important applications of DVM from the civil engineering point of view. Some examples known form literature are presented theoretical as well as experimental.
Źródło:
Budownictwo i Architektura; 2009, 5, 2; 29-38
1899-0665
Pojawia się w:
Budownictwo i Architektura
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rationality of solving 3D circulation problems exclusively with the use of the Navier-Stokes equation (Reynolds equation)
Autorzy:
Koronowicz, T.
Powiązania:
https://bibliotekanauki.pl/articles/1986684.pdf
Data publikacji:
2002
Wydawca:
Politechnika Gdańska
Tematy:
3D circulation problems
vortex theory
Navier-Stokes equation
Opis:
The paper presents problems connected with solving 3D circulation problems. The existence of vortex singularities in the flow behind a body is a characteristic feature of such problems. The vortices influence the velocity and pressure fields in the vicinity of a body. A proposition of rational merging the methods based on the N-S equation together with vortex methods (based on the vorticity equation) is discussed. Such a connection enables accurate and efficient determination of vortex singularities in the flow behind a body.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2002, 6, 1; 217-224
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
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:
Fast algorithms for calculations of viscous incompressible flows using the Velocity Correction Method
Autorzy:
Kosma, Z.
Motyl, Przemysław
Powiązania:
https://bibliotekanauki.pl/articles/1943235.pdf
Data publikacji:
2008
Wydawca:
Politechnika Gdańska
Tematy:
Navier-Stokes equation
artificial compressibility
method of lines
two grids method
Opis:
An artificial compressibility method is designed to simulate stationary two-and threedimensional motions of a viscous incompressible fluid. A standard method of lines approach is applied in this contribution. A partial differential equation system is discretized in space by secondorder finite-difference schemes on uniform computational grids, and the time-variable is preserved as continuous. Initial value problems for systems of ordinary differential equations for pressure and velocity components are computed using the Galerkin-Runge-Kutta method of third order. Some test calculations for laminar flows in square, cubic, triangular and semicircular cavities with one uniform moving wall and double bent channels are reported.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2008, 12, 3-4; 289-301
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fast algorithms for calculations of viscous incompressible flows using the artificial compressibility method
Autorzy:
Kosma, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1943234.pdf
Data publikacji:
2008
Wydawca:
Politechnika Gdańska
Tematy:
Navier-Stokes equation
velocity correction method
method of lines
two grids method
Opis:
The velocity correction method is designed to simulate stationary and non-stationary, two- and three-dimensional motions of a viscous incompressible fluid. The basic assumption of this method consists in splitting the velocity and the pressure fields and calculations are performed in two steps. In the first step, a tentative velocity field is determined by simplified equations for momentum conservation. In the second step the Neumann problem for the Poisson equations is solved to obtain the computational pressure, and the velocity components are corrected. A standard method of lines approach and the two grids method are applied in this contribution. Some test calculations for laminar and transitional flows in square and cubic cavities with one moving wall as well as in a backward-facing step are reported.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2008, 12, 3-4; 273-287
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Calculation of viscous incompressible flow around an aerofoil using a modified velocity correction method
Autorzy:
Kosma, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1965150.pdf
Data publikacji:
2005
Wydawca:
Politechnika Gdańska
Tematy:
Navier-Stokes equation
incompressible viscous flows
velocity correction method
flows over aerofoils
Opis:
The two-dimensional unsteady motion of viscous incompressible fluid around an aerofoil at a large angle of attack has been computed. A modified velocity correction method splitting the velocity field has been designed to solve this problem. First, a tentative velocity field is determined from the equations of momentum conservation for explicit gradients of computational pressure. Then, the Neumann problem for the Poisson equation is solved to estimate the computational pressure, and velocity components are corrected. Test calculations have been made for the case of flow around the NACA 0012 aerofoil with an incidence of 34 degrees. The domain outside the aerofoil was transformed into a canonical one using conformal mapping. Computations were made on 100×100 and 100×200 grids for Reynolds numbers of Re=400, 600 and 1000. Comparison with numerical and experimental data reported in the literature has shown that the method is suitable for simulating 2D external viscous flows.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2005, 9, 1; 37-52
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Oil pressure distribution in variable height gaps
Rozklady cisnienia oleju w szczelinach plaskich o zmiennej wysokosci
Autorzy:
Zloto, T.
Kowalski, K.
Powiązania:
https://bibliotekanauki.pl/articles/792863.pdf
Data publikacji:
2011
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Tematy:
variable height gap
pressure distribution
hydraulic oil
hydraulic machine
Navier-Stokes equation
Źródło:
Teka Komisji Motoryzacji i Energetyki Rolnictwa; 2011, 11C
1641-7739
Pojawia się w:
Teka Komisji Motoryzacji i Energetyki Rolnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Oil leaks intensity in variable-height gaps
Natężenie przepływu przecieków oleju w szczelinach o zmiennej wysokości
Autorzy:
Zloto, T.
Kowalski, K.
Powiązania:
https://bibliotekanauki.pl/articles/792722.pdf
Data publikacji:
2013
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Tematy:
variable height gap
hydraulic machine
Navier-Stokes equation
hydraulic oil
oil leakage
flow intensity
Źródło:
Teka Komisji Motoryzacji i Energetyki Rolnictwa; 2013, 13, 2
1641-7739
Pojawia się w:
Teka Komisji Motoryzacji i Energetyki Rolnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Flow behavior in weakly permeable micro-tube with varying viscosity near the wall
Autorzy:
Gupta, R. R.
Kumar, V.
Chand, S.
Powiązania:
https://bibliotekanauki.pl/articles/779656.pdf
Data publikacji:
2017
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
hollow-fiber
micro-tube
permeation
algorithm
variable viscosity
velocity profile
equation of motion
navier-stokes equation
Opis:
Weakly permeable micro-tubes are employed in many applications involving heat and/or mass transfer. During these processes, either solute concentration builds up (mass transfer) or steep change in temperature (heat transfer) takes place near the permeable wall causing a change in the viscosity of the fluid. Results of the present work suggest that such change in viscosity leads to a considerable alteration in the flow behavior, and the commonly assumed parabolic velocity profile no longer exists. To solve the problem numerically, the equation of motion was simplified to represent permeation of incompressible, Newtonian fluid with changing viscosity through a micro-tube. Even after considerable simplification, the accuracy of the results was the same as that obtained by previously reported results for some specific cases using rigorous formulation. The algorithm developed in the present work is found to be numerically robust and simple so that it can be easily integrated with other simulations.
Źródło:
Polish Journal of Chemical Technology; 2017, 19, 4; 16-21
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical investigation of flow in mixed-flow pump with volute
Autorzy:
Sedlar, M.
Powiązania:
https://bibliotekanauki.pl/articles/1967635.pdf
Data publikacji:
2001
Wydawca:
Politechnika Gdańska
Tematy:
CFD
computational fluid dynamics CFD
flow separation
cavitation
Navier-Stokes equation
unsteady phenomena
mixed-flow pump
volute
Opis:
The work considers the modelling of flow in a complete mixed-flow pump with volute, including tip leakage flows, using both quasi-steady and true transient models of rotor/stator interaction. The CFX-TASCflow CFD package from AEA Technology is applied to calculate flows for a wide range of flow rates from about 0.2 to 1.4 Q/sub 0pt/. Fairly detailed flow structures have been predicted based on the flow rates, especially impeller inlet recirculation and separation on the suction side of the blades for suboptimal rates of flow, as well as strong secondary flows and separation in the volute for off-design conditions. The rotor/stator interaction influence on flow phenomena both in the impeller and volute have been investigated with very interesting results, providing good insight into the dynamics of flow close to the volute tongue. Based on the computational results, pump performance curves (Q-H, Q- eta /sub h/ and Q-P, eta /sub h/ being the hydraulic efficiency) have been obtained. The data from this numerical investigation have been used to improve the inlet part of the impeller blades, especially close to the tip. The geometry modifications have resulted in reduced cavitation in the impeller as well as noise at suboptimal rates of flow.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2001, 5, 4; 595-602
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Method of lines for the incompressible Navier-Stokes equations in the stream-function formulation
Autorzy:
Kosma, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1965151.pdf
Data publikacji:
2005
Wydawca:
Politechnika Gdańska
Tematy:
Navier-Stokes equation
stream-function formulation
method of lines
compact schemes
driven cavity
backward-facing step flow
Opis:
The aim of this paper is to simulate the laminar motion of viscous incompressible fluid and the transition between the laminar and the turbulent state in simply connected domains. The developed numerical algorithms are based on the solution of an initial-boundary value problem for the full incompressible Navier-Stokes equations, written in the form of a fourth-order equation for the stream function. The spatial derivatives and the boundary conditions are discretized on uniform grids by means of sixth-order compact schemes together with fourth-order finite-difference formulas, while the continuity of the time variable is preserved. The resulting system of ordinary differential equations has been integrated using the backward-differentiation predictor-corrector method. The efficiency of the numerical algorithms is demonstrated by solving two problems of viscous liquid plane flows in a square driven cavity and a backward-facing step. Calculations for the cavity flow configuration have been obtained for Reynolds numbers ranging from Re=100 to Re=30000 on uniform 50×50 and 100×100 grids. Calculations for the backward-facing step have been made for Re ≤ 3000 with channel lengths, L, within the range 10-30, on 30L×30 uniform grids. The computed stream-function contours and velocity fields have been compared with numerical results reported in the literature.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2005, 9, 1; 17-35
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of CFD for analysis of the ship and propeller flow
Autorzy:
Bugalski, T. J.
Szantyr, J.
Powiązania:
https://bibliotekanauki.pl/articles/1953974.pdf
Data publikacji:
1998
Wydawca:
Politechnika Gdańska
Tematy:
computational fluid dynamics CFD
CFD
propeller flow
ships
Navier-Stokes equation
free surface
propeller operation
PANSHIP computer system
Opis:
The paper describes the computer system PANSHIP for analysis of flow around the ship hull moving with constant velocity in calm water, including the effects of free surface and propeller operation. This system calculates the potential flow using the discrete distribution of Rankine sources on the hull. Viscous flow is computed using the integral method in the bow section and Reynolds averaged Navier Stokes equation (RANS) in the stern section of the ship hull. Results of this analysis may be directly used in ship hull design and they may also serve as input for calculation of the unsteady flow phenomena accompanying propeller operation in the non-uniform velocity field generated by the hull. PANSHIP has been verified experimentally and it forms a useful tool available for ship designers and for marine hydrodynamicists.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 1998, 2, 2; 349-356
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An analysis of pressure distribution in water and water emulsion in a front gap of a hydrostatic bearing
Analiza rozkładu ciśnienia wody i emulsji wodnej w szczelinie czołowej łożyska hydrostatycznego
Autorzy:
Kowalski, K.
Zloto, T.
Powiązania:
https://bibliotekanauki.pl/articles/792293.pdf
Data publikacji:
2014
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Tematy:
pressure distribution
water
water emulsion
variable height gap
hydrostatic thrust bearing
Navier-Stokes equation
geometrical parameter
exploitation condition
Źródło:
Teka Komisji Motoryzacji i Energetyki Rolnictwa; 2014, 14, 4
1641-7739
Pojawia się w:
Teka Komisji Motoryzacji i Energetyki Rolnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pressure distributions in oil film in the front gap of a hydrostatic thrust bearing
Rozklady cisnienia w filmie olejowym szczeliny czolowej lozyska hydrostatycznego wzdluznego
Autorzy:
Zloto, T.
Kowalski, K.
Powiązania:
https://bibliotekanauki.pl/articles/793238.pdf
Data publikacji:
2012
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Tematy:
hydrostatic thrust bearing
pressure distribution
oil film
Navier-Stokes equation
geometrical dimension
exploitation parameter
front gap
geometrical parameter
Źródło:
Teka Komisji Motoryzacji i Energetyki Rolnictwa; 2012, 12, 2
1641-7739
Pojawia się w:
Teka Komisji Motoryzacji i Energetyki Rolnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Novel method of physical modes generation for reduced order flow control-oriented models
Autorzy:
Morzyński, M.
Nowak, M.
Stankiewicz, W.
Powiązania:
https://bibliotekanauki.pl/articles/127922.pdf
Data publikacji:
2014
Wydawca:
Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:
Navier-Stokes equation
eigenmodes
Reduced Order Modelling
flow control
równanie Naviera-Stokesa
postać drgań własnych
modelowanie zredukowanego rzędu
kontrola przepływu
Opis:
Physical flow modes are of particular interest for Reduced Order Flow Control-Oriented Models. Computation of physical modes as the eigensolution of linearized Navier-Stokes equations is a cumbersome and difficult task, especially for large, 3D problems. Instead we propose the solution of Navier-Stokes equation in the frequency domain and investigation of the system response to local or global perturbation. The flow variables are perturbed around steady basic state and the system response is used to construct mode basis suitable for ROMs.
Źródło:
Vibrations in Physical Systems; 2014, 26; 189-194
0860-6897
Pojawia się w:
Vibrations in Physical Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Oil pressure distribution in conical ring gaps
Rozklady cisnienia oleju w szczelinach pierscieniowych stozkowych
Autorzy:
Zloto, T.
Kowalski, K.
Powiązania:
https://bibliotekanauki.pl/articles/793712.pdf
Data publikacji:
2012
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Tematy:
piston-cylinder pump
pressure distribution
oil pressure distribution
conical ring gap
piston pump
hydraulic motor
Navier-Stokes equation
viscosity
hydraulic system
computational model
Źródło:
Teka Komisji Motoryzacji i Energetyki Rolnictwa; 2012, 12, 2
1641-7739
Pojawia się w:
Teka Komisji Motoryzacji i Energetyki Rolnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Studies of a mixing process induced by a rotating magnetic field with the application of magnetic particles
Autorzy:
Rakoczy, Rafał
Kordas, Marian
Markowska-Szczupak, Agata
Konopacki, Maciej
Augustyniak, Adrian
Jabłońska, Joanna
Paszkiewicz, Oliwia
Dubrowska, Kamila
Story, Grzegorz
Story, Anna
Ziętarska, Katarzyna
Sołoducha, Dawid
Borowski, Tomasz
Roszak, Marta
Grygorcewicz, Bartłomiej
Dołęgowska, Barbara
Powiązania:
https://bibliotekanauki.pl/articles/2086782.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
mixing process
alternating magnetic field
magnetic particles
mixing time
Navier–Stokes equation
proces mieszania
zmienne pole magnetyczne
cząstki magnetyczne
czas mieszania
równanie Naviera-Stokesa
Opis:
We demonstrate in this study that a rotating magnetic field (RMF) and spinning magnetic particles using this kind of magnetic field give rise to a motion mechanism capable of triggering mixing effect in liquids. In this experimental work two mixing mechanisms were used, magnetohydrodynamics due to the Lorentz force and mixing due to magnetic particles under the action of RMF, acted upon by the Kelvin force. To evidence these mechanisms, we report mixing time measured during the neutralization process (weak acid-strong base) under the action of RMF with and without magnetic particles. The efficiency of the mixing process was enhanced by a maximum of 6.5% and 12.8% owing to the application of RMF and the synergistic effect of magnetic field and magnetic particles, respectively
Źródło:
Chemical and Process Engineering; 2021, 42, 2; 157--172
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stabilization of a fluid structure interaction with nonlinear damping
Autorzy:
Lasiecka, I.
Lu, Y.
Powiązania:
https://bibliotekanauki.pl/articles/206598.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
fluid structure interaction
interface
Navier-Stokes equation
system of elasticity
feedback boundary control
strong stability
uniform stability
optimal control
passive damping
active damping
dynamic and static damping
Opis:
Asymptotic stability of finite energy solutions to a fluid-structure interaction with a static interface in a bounded domain Ω ∈ Rn, n = 2 is considered. It is shown that the undamped model subject to ”partial flatness” geometric condition on the in- terface produces solutions whose energy converges strongly to zero; while with a stress type feedback control applied on the interface of the structure, the model produces solutions whose energy is exponentially stable. An addition of a static damping on the interface produces solutions whose full norm in the phase space is exponentially stable. Without a static damping an interesting phenomenon occurs that steady state solutions (equilibria) might generate genuinely growing in time solutions. This is purely nonlinear phenomenon captured by newly developed techniques amenable to handle instability of steady state solutions arising from nonlinearity.
Źródło:
Control and Cybernetics; 2013, 42, 1; 155-181
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dusty time fractional MHD flow of a Newtonian fluid through a cylindrical tube with a non-Darcian porous medium
Autorzy:
Imo-Mani-Singha, H.
Sengupta, Sanjib
Powiązania:
https://bibliotekanauki.pl/articles/1839832.pdf
Data publikacji:
2020
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
time-fractional order Navier-Stokes equation
Laplace decomposition method
LDM
Magnetohydrodynamics
MHD
dusty flow
non-Darcy porous medium
ciecz newtonowska
przepływ cieczy nienewtonowskiej
Laplace Decomposition Method
magnetohydrodynamika
Opis:
In this paper, time fractional flow of a Newtonian fluid through a uniform cylindrical tube with a non-Darcy porous medium in the presence of dust particles under the application of a uniform magnetic field along the meridian axis is discussed. The implication of time fractional order differential equations in flow problems and some benefits of fractional order differential equations are highlighted. The Laplace Decomposition Method (LDM) is used to obtain an approximate solution to the proposed problem. The impact of fractional order and integer order of the differential equations and also the effects of some important parameters on the flow system are shown in the forms of graphs and a table. The convergence test of the solution is done. It has been observed that the fractional order differential equation reveals more things like the decrease in dust particle velocity due to the increase in magnetic field for fractional order derivatives, whereas, no noticeable change in dust particle velocity due to the change in magnetic field for integer order derivatives are observed. Also, it is observed that an increase in a fractional order derivative decrease the fluid as well as the dust particle velocities. The skin friction at the walls of the tube are also highlighted.
Źródło:
Journal of Applied Mathematics and Computational Mechanics; 2020, 19, 4; 101-114
2299-9965
Pojawia się w:
Journal of Applied Mathematics and Computational Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
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:
Dusty time fractional MHD flow of a Newtonian fluid through a cylindrical tube with a non-Darcian porous medium
Autorzy:
Imo-Mani-Singha, H.
Sengupta, Sanjib
Powiązania:
https://bibliotekanauki.pl/articles/1839728.pdf
Data publikacji:
2020
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
time-fractional order Navier-Stokes equation
Laplace decomposition method
LDM
Magnetohydrodynamics
MHD
dusty flow
non-Darcy porous medium
ciecz newtonowska
przepływ cieczy nienewtonowskiej
Laplace Decomposition Method
magnetohydrodynamika
Opis:
In this paper, time fractional flow of a Newtonian fluid through a uniform cylindrical tube with a non-Darcy porous medium in the presence of dust particles under the application of a uniform magnetic field along the meridian axis is discussed. The implication of time fractional order differential equations in flow problems and some benefits of fractional order differential equations are highlighted. The Laplace Decomposition Method (LDM) is used to obtain an approximate solution to the proposed problem. The impact of fractional order and integer order of the differential equations and also the effects of some important parameters on the flow system are shown in the forms of graphs and a table. The convergence test of the solution is done. It has been observed that the fractional order differential equation reveals more things like the decrease in dust particle velocity due to the increase in magnetic field for fractional order derivatives, whereas, no noticeable change in dust particle velocity due to the change in magnetic field for integer order derivatives are observed. Also, it is observed that an increase in a fractional order derivative decrease the fluid as well as the dust particle velocities. The skin friction at the walls of the tube are also highlighted.
Źródło:
Journal of Applied Mathematics and Computational Mechanics; 2020, 19, 4; 101-114
2299-9965
Pojawia się w:
Journal of Applied Mathematics and Computational Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of a near wall model to Navier-Stokes equations with nonlinear time-relaxation model
Autorzy:
İhan, Özgül
Powiązania:
https://bibliotekanauki.pl/articles/2175530.pdf
Data publikacji:
2022
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
boundary layers
laminar
near wall models
NWM
Navier-Stokes equation with nonlinear time-relaxation model
NSE-NTR
warstwy graniczne
równanie Naviera-Stokesa z nieliniowym modelem relaksacji w czasie
Opis:
It is difficult and essential to determine appropriate boundary conditions for the flow averages because they depend on the behavior of the unknown flow near the wall. Large-eddy simulation (LES) is one of the promising approaches. LES estimates local spatial averages ū of the velocity u of the fluid. The main problem is modeling near-wall turbulence in complex geometries. Inspired by the works of Navier and Maxwell, the boundary conditions are developed on the wall. In this study, the appropriate friction coefficient for 2-D laminar flows is computed, and existing boundary layer theories are used to improve numerical boundary conditions for flow averages. The slip with friction and penetration with resistance boundary conditions are considered. Numerical tests on two-dimensional channel flow across a step using this boundary condition on the top and bottom wall and the step are performed.
Źródło:
Journal of Applied Mathematics and Computational Mechanics; 2022, 21, 2; 39--50
2299-9965
Pojawia się w:
Journal of Applied Mathematics and Computational Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On free convection heat transfer from vertical plate - proposition of a new model
Autorzy:
Leble, S.
Lewandowski, W. M.
Powiązania:
https://bibliotekanauki.pl/articles/1938587.pdf
Data publikacji:
2016
Wydawca:
Politechnika Gdańska
Tematy:
Navier-Stokes equations
Fourier-Kirchhoff equation
free convective heat transfer
analytical solution
sothermal surface
boundary layer
vertical plate
Opis:
The free convection heat transfer from an isothermal vertical plate in open space is investigated theoretically. In contrast to conventional approaches we use neither boundary layer nor self-similarity concepts. We base on expansion of the fields of velocity and temperature in a Taylor Series in x coordinate with coefficients being functions of the vertical coordinate (y). In the minimal version of the theory we restrict ourselves by cubic approximation for both functions. The Navier-Stokes and Fourier-Kirchhoff equations that describe the phenomenon give links between coefficient functions of y that after exclusion leads to the ordinary differential equation of forth order (of the Mittag-Leffleur type). Such construction implies four boundary conditions for a solution of this equation while the links between the coefficients need two extra conditions. All the conditions are chosen on the basis of the experience usual for free convection. The choice allows us to express all the theory parameters as functions of the Rayleigh number and the temperature difference. To support the conformity of the theory we derive the Nusselt-Rayleigh numbers relation that has the traditional form. The solution in the form of velocity and temperature profiles is evaluated and illustrated for air by examples of plots of data.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2016, 20, 2; 249-265
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling of heat transfer and fluid flow in a rectangular channel with an obstacle
Autorzy:
Stryczyński, Mikołaj
Majchrzak, Ewa
Powiązania:
https://bibliotekanauki.pl/articles/1839780.pdf
Data publikacji:
2020
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
channel with an obstacle
Fourier-Kirchhoff equation
Navier-Stokes equations
finite difference method
równanie Fouriera-Kirchhoffa
równania Naviera-Stokesa
metoda różnic skończonych
Opis:
Heat transfer and fluid flow in the rectangular channel with an obstacle are considered. The problem is described by the Fourier-Kirchhoff equation, Navier-Stokes equations and continuity equation supplemented by appropriate boundary and initial conditions. To solve this system of equations the finite difference method with a staggered grid is used. The results of computations obtained using authorial computer program are compared with ANSYS Fluent simulation. Computations are carried out for obstacles of various sizes and positions, and on this basis the conclusions are formulated.
Źródło:
Journal of Applied Mathematics and Computational Mechanics; 2020, 19, 2; 121-132
2299-9965
Pojawia się w:
Journal of Applied Mathematics and Computational Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
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