Development of a fast-response calorimeter heat transfer gauge for hypersonic ground testing

A robust, fast response calorimeter based heat transfer gauge called the Diamond Heat Transfer Gauge (DHTG) has been developed for use in transient hypersonic ground test facilities. Desirable response time and robustness are achieved by using a 75 μm to 300 μm thick layer of synthetic diamond as the calorimeter and a platinum thin film resistance thermometer to measure the temperature rise. Different versions of the gauge have been shown experimentally to have a rise time of between 7 μs and 28 μs. The gauges have measured peak heat fluxes up to 300MW /m in flows with total enthalpies of 50 MJ/kg over multiple shots in the X2 expansion tunnel at the University of Queensland. Experimentally measured heat fluxes have been shown to compare well with surface junction thermocouples and thin film heat transfer gauges.