DEVELOPMENT OF A COUPLED INLET-ENGINE DYNAMIC ANALYSIS METHOD

A new method is presented for unsteady analysis of turbine engine propulsion systems. The method is a coupled analysis of the inlet-compressor combination with multidimensional inlet capability. The method incorporates unstructured, inviscid, unsteady inlet computational fluid dynamics and a onedimensional dynamic turbomachinery model. The present application of the method is an axisymmetric mixed compression inlet with an eight stage axial compressor of a turbojet engine. The inlet simulation includes geometric details not previously included hi strictly one-dimensional analyses. Simulation of two events are compared to experimental data for Mach 2.5 freestream conditions. The first event is an inlet unstart triggered by bypass flow throttling, resulting in a subsequent compressor stall. The second event is a compressor stall triggered by nozzle throttling resulting in a subsequent inlet unstart and strong hammershock. Favorable results are achieved for both cases.