Poppet Valve Control of Throat Stability Bypass to Increase Stable Airflow Range of a Mach 2.5. Inlet with 60 Percent Internal ContractionThe 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 configuration 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. |
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40 reciprocal seconds Airflow index Axial distance bench test data bleed systems boundary layer bypass airflow bypass entrance configuration bypass exit control bypass plenum bypass system centerbody bleed choke point coldpipe corrected airflow cowl bleed region cowl lip diffuser exit diffuser-exit Distributed educated distributed porous Forward cowl bleed forward-slanted slot inlet operating point inlet performance inlet radii inlet total-pressure recovery inlet volume installed large slot Large stability-bypass plenum large stable airflow Mach 2.5 Inlet Mach number NASA NASA TM oblique shock overboard-bypass performance bleed performance map poppet valve control porous configuration predicted from bench Rake shown in figure small stability-bypass plenum stability index obtained stability-bypass airflow stability-bypass entrance configuration stability-bypass exit area stability-bypass exit controls stability-bypass flow Stability-bypass mass-flow ratio Stability-bypass performance Stability-bypass plenum volume stability-bypass system Stability-bypass total-pressure recovery stable airflow range supercritical Supersonic terminal shock transient pulse frequency transient stability index United Aircraft Corp unstart x/Rc