Compressible Navier (compressible + navier)

Distribution by Scientific Domains


Selected Abstracts


Compressible Navier,Stokes system in 1-D

MATHEMATICAL METHODS IN THE APPLIED SCIENCES, Issue 9 2001
Piotr Bogus, aw Mucha
Abstract The compressible barotropic Navier,Stokes system in monodimensional case with a Neumann boundary condition given on a free boundary is considered. The global existence with uniformly boundedness for large initial data and a positive force is proved. The result concerning an asymptotic behavior shows that the solutions tends to the stationary solution. Copyright 2001 John Wiley & Sons, Ltd. [source]


Numerical simulations of a transient injection flow at low Mach number regime

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 5 2008
A. Beccantini
Abstract In this paper, a transient injection flow at low Mach number regime is investigated. Three different methods are used and analyzed. Two of them are based on asymptotic models of the Navier,Stokes equations valid for small Mach numbers, whereas the other is based on the full compressible Navier,Stokes equations, with particular care given to the discretization at low Mach numbers. Numerical solutions are computed both with or without the gravity force. Finally, the performance of the solvers in terms of CPU-time consumption is investigated, and the sensitivity of the solution to some parameters, which affect CPU time is also performed. Copyright 2008 John Wiley & Sons, Ltd. [source]


Simulation of multiple shock,shock interference using implicit anti-diffusive WENO schemes

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 2 2010
Tsang-Jen Hsieh
Abstract Accurate computations of two-dimensional turbulent hypersonic shock,shock interactions that arise when single and dual shocks impinge on the bow shock in front of a cylinder are presented. The simulation methods used are a class of lower,upper symmetric-Gauss,Seidel implicit anti-diffusive weighted essentially non-oscillatory (WENO) schemes for solving the compressible Navier,Stokes equations with Spalart,Allmaras one-equation turbulence model. A numerical flux of WENO scheme with anti-diffusive flux correction is adopted, which consists of first-order and high-order fluxes and allows for a more flexible choice of first-order dissipative methods. Experimental flow fields of type IV shock,shock interactions with single and dual incident shocks by Wieting are computed. By using the WENO scheme with anti-diffusive flux corrections, the present solution indicates that good accuracy is maintained and contact discontinuities are sharpened markedly as compared with the original WENO schemes on the same meshes. Computed surface pressure distribution and heat transfer rate are also compared with experimental data and other computational results and good agreement is found. Copyright 2009 John Wiley & Sons, Ltd. [source]


Nonreflecting boundary conditions based on nonlinear multidimensional characteristics

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 1 2010
Qianlong Liu
Abstract Nonlinear characteristic boundary conditions based on nonlinear multidimensional characteristics are proposed for 2- and 3-D compressible Navier,Stokes equations with/without scalar transport equations. This approach is consistent with the flow physics and transport properties. Based on the theory of characteristics, which is a rigorous mathematical technique, multidimensional flows can be decomposed into acoustic, entropy, and vorticity waves. Nonreflecting boundary conditions are derived by setting corresponding characteristic variables of incoming waves to zero and by partially damping the source terms of the incoming acoustic waves. In order to obtain the resulting optimal damping coefficient, analysis is performed for problems of pure acoustic plane wave propagation and arbitrary flows. The proposed boundary conditions are tested on two benchmark problems: cylindrical acoustic wave propagation and the wake flow behind a cylinder with strong periodic vortex convected out of the computational domain. This new approach substantially minimizes the spurious wave reflections of pressure, density, temperature, and velocity as well as vorticity from the artificial boundaries, where strong multidimensional flow effects exist. The numerical simulations yield accurate results, confirm the optimal damping coefficient obtained from analysis, and verify that the method substantially improves the 1-D characteristics-based nonreflecting boundary conditions for complex multidimensional flows. Copyright 2009 John Wiley & Sons, Ltd. [source]


LES of the compressed Taylor vortex flow using a finite volume/finite element method on unstructured grids

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 4 2006
C. Le Ribault
Abstract Large-eddy simulations (LES) have been performed of a compressed vortex flow undergoing transition to turbulence. The numerical method is based on a finite volume/finite element discretization of the compressible Navier,Stokes equations on unstructured grids and a Roe second-order scheme with MUSCL extrapolation. A particular attention is paid to the dissipative character of the method, controlled by a coefficient related to the upwind part of the numerical scheme, and its interference with the subgrid model. The accuracy of the method is first checked in the case of decaying homogeneous isotropic turbulence. The investigation is then directed to a plane Taylor vortex flow submitted to compression, in a direction perpendicular to the vorticity vector. This flow is unstable with respect to three-dimensional perturbations and transition to turbulence is observed if the Reynolds number is large enough. The numerical method is used to simulate this vortex flow for two values of the Reynolds number. For the lower value, the flow is unstable but remains laminar and no subgrid model is used. For the higher one, the turbulence appears and the standard and the dynamic Smagorinsky models are tested. The LES results are compared to those obtained by direct numerical simulations (DNS) using a spectral Fourier method. Copyright 2006 John Wiley & Sons, Ltd. [source]


A complete boundary integral formulation for compressible Navier,Stokes equations

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 12 2005
Yang ZuoshengArticle first published online: 29 DEC 200
Abstract A complete boundary integral formulation for compressible Navier,Stokes equations with time discretization by operator splitting is developed using the fundamental solutions of the Helmholtz operator equation with different order. The numerical results for wall pressure and wall skin friction of two-dimensional compressible laminar viscous flow around airfoils are in good agreement with field numerical methods. Copyright 2004 John Wiley & Sons, Ltd. [source]


Modelling and simulation of fires in vehicle tunnels

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 3 2004
I. Gasser
Abstract Applying a low-Mach asymptotic for the compressible Navier,Stokes equations, we derive a new fluid dynamics model,which should be capable to model large temperature differences in combination with the low-Mach number limit. The model is used to simulate fires in vehicle tunnels, where the standard Boussinesq-approximation for the incompressible Navier,Stokes seems to be inappropriate due to the high temperatures developing in the tunnel. The model is implemented using a modified finite-difference approach for the incompressible Navier,Stokes equations and tested in some realistic fire events. Copyright 2004 John Wiley & Sons, Ltd. [source]


Numerical evaluation of two discontinuous Galerkin methods for the compressible Navier,Stokes equations

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 1-2 2002
F. Bassi
This paper presents a critical comparison between two recently proposed discontinuous Galerkin methods for the space discretization of the viscous terms of the compressible Navier,Stokes equations. The robustness and accuracy of the two methods has been numerically evaluated by considering simple but well documented classical two-dimensional test cases, including the flow around the NACA0012 airfoil, the flow along a flat plate and the flow through a turbine nozzle. Copyright 2002 John Wiley & Sons, Ltd. [source]


Analysis of super compact finite difference method and application to simulation of vortex,shock interaction

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 7 2001
Fu Dexun
Abstract Turbulence and aeroacoustic noise high-order accurate schemes are required, and preferred, for solving complex flow fields with multi-scale structures. In this paper a super compact finite difference method (SCFDM) is presented, the accuracy is analysed and the method is compared with a sixth-order traditional and compact finite difference approximation. The comparison shows that the sixth-order accurate super compact method has higher resolving efficiency. The sixth-order super compact method, with a three-stage Runge,Kutta method for approximation of the compressible Navier,Stokes equations, is used to solve the complex flow structures induced by vortex,shock interactions. The basic nature of the near-field sound generated by interaction is studied. Copyright 2001 John Wiley & Sons, Ltd. [source]


Towards a transparent boundary condition for compressible Navier,Stokes equations

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 7 2001
C. H. Bruneau
Abstract A new artificial boundary condition for two-dimensional subsonic flows governed by the compressible Navier,Stokes equations is derived. It is based on the hyperbolic part of the equations, according to the way of propagation of the characteristic waves. A reference flow, as well as a convection velocity, is used to properly discretize the terms corresponding to the entering waves. Numerical tests on various classical model problems, whose solutions are known, and comparisons with other boundary conditions (BCs), show the efficiency of the BC. Direct numerical simulations of more complex flows over a dihedral plate are simulated, without creation of acoustic waves going back in the flow. Copyright 2001 John Wiley & Sons, Ltd. [source]


Stability of weak solutions to the compressible Navier,Stokes equations in bounded annular domains

MATHEMATICAL METHODS IN THE APPLIED SCIENCES, Issue 2 2008
Jishan Fan
Abstract We prove the Lipschitz continuous dependence on initial data of global spherically symmetric weak solutions to the Navier,Stokes equations of a viscous polytropic ideal gas in bounded annular domains with the initial data in the Lebesgue spaces. Copyright 2007 John Wiley & Sons, Ltd. [source]


On the domain dependence of solutions to the compressible Navier,Stokes equations of a barotropic fluid

MATHEMATICAL METHODS IN THE APPLIED SCIENCES, Issue 12 2002
Eduard Feireisl
We prove a general compactness result for the solution set of the compressible Navier,Stokes equations with respect to the variation of the underlying spatial domain. Among various corollaries, we then prove a general existence theorem for the system in question with no restrictions on smoothness of the spatial domain. Copyright 2002 John Wiley & Sons, Ltd. [source]


Asymptotic behaviour for a non-monotone fluid in one dimension: the positive temperature case

MATHEMATICAL METHODS IN THE APPLIED SCIENCES, Issue 8 2001
B. Ducomet
We consider a one-dimensional continuous model of neutron star, described by a compressible Navier,Stokes system with a non-monotone equation of state, due to the effective Skyrme nuclear interaction between particles. We study the asymptotic behaviour of globally defined solutions of a mixed free boundary problem for our model, for large time, assuming that a sufficient thermal dissipation is present. Copyright 2001 John Wiley & Sons, Ltd. [source]