In this paper, we extend the high order finite-difference method with subcell resolution (SR) in [34] for two-species stiff one-reactionmodels to multispecies and multireaction inviscid chemical reactive flows, which are significantly more difficult because of the multiple scales generated by different reactions. For reaction problems, when the reaction time scale is very small, the reaction zo...

Two distinct redistribution grids - adaptation techniques, spring analogy and elliptic grid generator are applied to two-dimensional steady, inviscid, shocked flows, and the ability of each technique is examined and compared. Euler equations are solved base on Roe's Reimann solver approach to simulate supersonic flow around a sphere, transonic flow about an airfoil and supersonic flow in a symm...

accurate prediction of pollution control and environmental protection need a good understanding of pollutant dynamics. numerical model techniques are important apparatus in this research area. so a 2500 line fortran 95 version code was conducted in which using approximate riemann solver, couples the shallow water and pollution transport agents in two dimensions by the aid of unstructured meshes...

Direct numerical simulation of the wake flow around and behind a planar ellipse using a random vortex method is presented. Fluid is considered incompressible and the aspect ratios of ellipse and the angles of attacks are varied. This geometry can be a logical prelude to the more complex geometries, but less time dependent experimental measurements are available to validate the numerical results...

The dynamics of compressible liquid-vapor flow depends sensitively on the microscale behavior at phase boundary. We consider a sharp-interface approach, and propose multiscale model to describe accurately, without imposing ad-hoc closure relations continuum scale. combines Euler equations scale with molecular-scale particle simulations that govern interface motion. rely an interface-preserving ...

Finite volume schemes often have difficulties to resolve the low Mach number (incompressible) limit of Euler equations. Incompressibility is only non-trivial in multiple spatial dimensions. Low fixes, however generally are applied one-dimensional method and then used a dimensionally split way. This reduces its stability. Here, it suggested keep as is, extend dimensions particular, all-speed str...

The paper presents a new simulation method for airbags with multiple compartments. In recent years many accidents happened with passengers that were out of position (OOP) when their airbag deployed. Therefore new safety regulations have come into effect in the USA and an airbag now has to meet several requirements that concern out of positioning. In meeting these requirements simulations of dep...

A new multi-state Harten–Lax–van Leer (HLL) approximate Riemann solver for the ideal magnetohydrodynamic (MHD) equations is developed based on the assumption that the normal velocity is constant over the Riemann fan. This assumption is same as that used in the HLLC (‘‘C’’ denotes Contact) approximate Riemann solver for the Euler equations. From the assumption, it is naturally derived that the R...

One major challenge in applying the adjoint method to large industrial cases is the lack of robustness of the flow and adjoint solvers. Discrete adjoints transpose the Jacobian of the system of discretised equations exactly, and hence inherit the linear stability from the primal flow solver. Typically the linear stability properties of the iterative scheme of the flow solver is very well unders...

A pressure-based implicit procedure to solve the Euler and Navier-Stokes equations on a nonorthogonal mesh with collocated finite volume formulation is described. The boundedness criteria for this procedure are determined from Normalized Variable diagram (NVD) scheme.The procedure incorporates the ε−k eddy-viscosity turbulence model. The algorithm is tested for inviscid and turbulent transonic ...