POPPET VALVE CONTROL OF THROAT STABILITY BYPASS TO INCREASE STABLE AIRFLOW RANGE OF A MACH 2.5 INLET WITH 60 PERCENT INTERNAL CONTRACTION

摘要

The throat of a Mach 2.5 inlet with a coldpipe termination was fitted with a stability-bypass system. System variations included several stability-bypass entrance configurations. Poppet valves controlled the bypass airflow. The inlet stable airflow range achieved with each config-uration was determined for both steady-state conditions and internal pulse transients. Results are compared with those obtained without a stability-bypass system. Transient results were also obtained for the inlet with a choke point at the diffuser exit and for the inlet with large and small stability-bypass plenum volumes. Poppet valves at the stability-bypass exit provided the inlet with a stable airflow range of 20 percent or greater at all static and transient conditions.