A SIMPLE SHOCK TUNNEL DRIVER GAS DETECTOR

A device has been developed to detect the arrival of the driver gas in a shock tunnel. The detector is small enough to be used in conjunctio n with other experiments. It works by choking a duct when the specific heat ratio is increased past a critical value. Times are given for th e onset of a 7.5% contamination level in flows with freestream enthalp ies ranging from 3-9 MJ/kg. These results are compared with and are sh own to be in agreement with measurements made with a mass spectrometer . Results displaying the rate at which the test gas is contaminated ar e also given.