Search for a command to run...
Experiments in both a shock tunnel and hotshot have proven the feasibility of using pulse facilities for advanced inlet testing. An internal contraction inlet tested at a hypersonic Mach number in a hotshot facility was successfully started at its maximum running contraction and with a choked exit nozzle. Close correlation with wind-tunnel data was achieved with the throttle in both supercritical and subcritical positions. An unthrottled hypervelocity inlet was started in a shock tunnel at a contraction ratio of 25/1. Surface pressures and friction gages were used to determine performance. Significant time-dependent flow adjustments were detected in both tests. Additional tests were performed in the hotshot using the exothermic decomposition of nitrous oxide as a heat supplement. Near-instantaneous reactions were achieved, resulting in pressures much higher than those attainable by arc heating alone. NO2 contamination was detected but was found to be an inverse function of N 2O load pressure and concentration. Theoretical calculations indicate that small amounts of hydrogen can produce an additional large pressure increase. The usefulness of pulse facilities in obtaining real gas and wall cooling data is discussed, and an inlet model designed for this purpose is briefly described.