Efficient Euler Analysis of Transonic Flow Around Advanced Turbo-Prop.

A fast explicit multi-grid scheme proposed by NI has been applied to steady transonic flows around eight bladed SR-3 advanced turbo-prop. FVI(Finite Volume Integral) used in one step distribution formula was implemented more easily by representing Euler equations in cartesian coordinate system. One step distribution formula obtained from Lax-Wendroff type differencing were used only for coarse grid calculations without FVI, so the increase in computational work per iteration was about only 10% compared with 25% in full approximation scheme. And by using standard coarsening and straight injecton for restriction, no additional memory was needed. Artificial viscosity and boundary conditions were applied only in the finest grid level, so the efficiency of multi-grid scheme was nearly independent of them. About 60% saving in computing time was obtained with 4 levels of coarse grid. The calculations were performed in CRAY-2S super-computer with 65x33x17 C-H type grid generated by algebraic method, and the results were compared with previous Euler analyses and experimental data.