Finite-volume scheme for multicomponent compressible flows on unstructured meshes in the focus 3D code

A finite-volume Godunov-type scheme for ideal multicomponent gas dynamics equations on a stationary three-dimensional unstructured mesh is described. The scheme is implemented in the Focus code intended for computations of compressible unstable and turbulent flows. The fluxes of conservative variables through cell faces are computed using the HLL and HLLC Riemann solvers generalized to an arbitrary face orientation without passing to a local coordinate system of each face. The velocity components are reconstructed taking into account the flow direction, which improves the description of spherically symmetric flows.