Numerical simulation of blast flowfields using MacCormack's method coupled with Kentzer's characteristic based boundary conditions

A numerical algorithm based on the unsteady three-dimensional method of characteristics is presented for calculating transient blast flowfields. A conservation form of the Euler equations are solved using the MacCormack explicit finite difference method. Artificial dissipation is included in the governing equations to aid in shock wave capturing and steady-state convergence. Compatibility equations in conservation variables are applied at the boundaries of the flowfield using the Kentzer method. The Kentzer method which is based on characteristic theory and employs a finite difference method to solve the compatibility equations. The scheme is second-order accurate. Comparisons are conducted for a steady axisymmetric nozzle and an unsteady open ended shock tube, The numerical solutions predicted by the methodology are in excellent agreement with experimentally measured results.