COMPARISON OF REAL-GAS SIMULATIONS USING DIFFERENT NUMERICAL-METHODS

Two different numerical simulation codes (the SPLIT/NE code and the Po liTo code) are examined in this paper by comparing results for non-equ ilibrium flow cases using two different geometries, a hemisphere-cylin der-flare (axisymmetric) and a hyperbola-flare-cylinder configuration (axisymmetric and 2-D plane). The solution methods implemented in the codes are essentially different (finite difference, bow shock fitting, matrix splitting and Runge-Kutta high accuracy schemes for SPLIT/NE a nd finite volume, shock capturing, flux difference splitting and E.N.O . high accuracy schemes for PoliTo). The flow simulations are done emp loying physical models of different complexity (inviscid and viscous f lows, chemically reacting flows in vibrational equilibrium and non-equ ilibrium, steady and unsteady hows). Comparing the solutions for the d ifferent codes, a very good agreement is obtained for both the hemisph ere-cylinder-flare flow and the 2-D plane hyperbola-flare-cylinder flo w. For relatively small flare angles, this is also true for the axisym metric hyperbola-flare-cylinder flow; however, for larger flare angles , differences in the solutions can be detected which can be addressed to the formation of a strong recirculation bubble behind the detached flare shock.