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Calculation of low Mach number acoustics : a comparison of MPV, EIF and linearized Euler equations

Sabine Roller, Thomas Schwartzkopff, Roland Fortenbach, Michael Dumbser, Claus-Dieter Munz (2005)

ESAIM: Mathematical Modelling and Numerical Analysis - Modélisation Mathématique et Analyse Numérique

The calculation of sound generation and propagation in low Mach number flows requires serious reflections on the characteristics of the underlying equations. Although the compressible Euler/Navier-Stokes equations cover all effects, an approximation via standard compressible solvers does not have the ability to represent acoustic waves correctly. Therefore, different methods have been developed to deal with the problem. In this paper, three of them are considered and compared to each other. They...

Calculation of low Mach number acoustics: a comparison of MPV, EIF and linearized Euler equations

Sabine Roller, Thomas Schwartzkopff, Roland Fortenbach, Michael Dumbser, Claus-Dieter Munz (2010)

ESAIM: Mathematical Modelling and Numerical Analysis

The calculation of sound generation and propagation in low Mach number flows requires serious reflections on the characteristics of the underlying equations. Although the compressible Euler/Navier-Stokes equations cover all effects, an approximation via standard compressible solvers does not have the ability to represent acoustic waves correctly. Therefore, different methods have been developed to deal with the problem. In this paper, three of them are considered and compared to each other....

Central-upwind schemes for the Saint-Venant system

Alexander Kurganov, Doron Levy (2002)

ESAIM: Mathematical Modelling and Numerical Analysis - Modélisation Mathématique et Analyse Numérique

We present one- and two-dimensional central-upwind schemes for approximating solutions of the Saint-Venant system with source terms due to bottom topography. The Saint-Venant system has steady-state solutions in which nonzero flux gradients are exactly balanced by the source terms. It is a challenging problem to preserve this delicate balance with numerical schemes. Small perturbations of these states are also very difficult to compute. Our approach is based on extending semi-discrete central schemes...

Central-Upwind Schemes for the Saint-Venant System

Alexander Kurganov, Doron Levy (2010)

ESAIM: Mathematical Modelling and Numerical Analysis

We present one- and two-dimensional central-upwind schemes for approximating solutions of the Saint-Venant system with source terms due to bottom topography. The Saint-Venant system has steady-state solutions in which nonzero flux gradients are exactly balanced by the source terms. It is a challenging problem to preserve this delicate balance with numerical schemes. Small perturbations of these states are also very difficult to compute. Our approach is based on extending semi-discrete central...

Combined finite element -- finite volume method (convergence analysis)

Mária Lukáčová-Medviďová (1997)

Commentationes Mathematicae Universitatis Carolinae

We present an efficient numerical method for solving viscous compressible fluid flows. The basic idea is to combine finite volume and finite element methods in an appropriate way. Thus nonlinear convective terms are discretized by the finite volume method over a finite volume mesh dual to a triangular grid. Diffusion terms are discretized by the conforming piecewise linear finite element method. In the paper we study theoretical properties of this scheme for the scalar nonlinear convection-diffusion...

Comparison of active control techniques over a dihedral plane

Emmanuel Creusé (2001)

ESAIM: Control, Optimisation and Calculus of Variations

This work is devoted to the numerical comparison of four active control techniques in order to increase the pressure recovery generated by the deceleration of a slightly compressible viscous flow over a dihedral plane. It is performed by the use of vortex generator jets and intrusive sensors. The governing equations, the two-dimensional direct numerical simulation code and the flow configuration are first briefly recalled. Then, the objective of the control is carefully displayed, and the uncontrolled...

Comparison of active control techniques over a dihedral plane

Emmanuel Creusé (2010)

ESAIM: Control, Optimisation and Calculus of Variations

This work is devoted to the numerical comparison of four active control techniques in order to increase the pressure recovery generated by the deceleration of a slightly compressible viscous flow over a dihedral plane. It is performed by the use of vortex generator jets and intrusive sensors. The governing equations, the two-dimensional direct numerical simulation code and the flow configuration are first briefly recalled. Then, the objective of the control is carefully displayed, and the uncontrolled...

Compressible two-phase flows by central and upwind schemes

Smadar Karni, Eduard Kirr, Alexander Kurganov, Guergana Petrova (2004)

ESAIM: Mathematical Modelling and Numerical Analysis - Modélisation Mathématique et Analyse Numérique

This paper concerns numerical methods for two-phase flows. The governing equations are the compressible 2-velocity, 2-pressure flow model. Pressure and velocity relaxation are included as source terms. Results obtained by a Godunov-type central scheme and a Roe-type upwind scheme are presented. Issues of preservation of pressure equilibrium, and positivity of the partial densities are addressed.

Compressible two-phase flows by central and upwind schemes

Smadar Karni, Eduard Kirr, Alexander Kurganov, Guergana Petrova (2010)

ESAIM: Mathematical Modelling and Numerical Analysis

This paper concerns numerical methods for two-phase flows. The governing equations are the compressible 2-velocity, 2-pressure flow model. Pressure and velocity relaxation are included as source terms. Results obtained by a Godunov-type central scheme and a Roe-type upwind scheme are presented. Issues of preservation of pressure equilibrium, and positivity of the partial densities are addressed.

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