Development of a Fast-Response Diamond Calorimeter Heat Transfer Gauge

Abstract

A robust fast-response calorimeter heat transfer gauge called the Diamond Heat Transfer Gauge has been developed for use in transient hypersonic ground test facilities. Gauges have been produced using discs of synthetic diamond thick as calorimeters with platinum thin-film resistance temperature detectors on the rear surface to measure temperature rise. Depending on calorimeter thickness and the grade of diamond used, the 99% rise time of the gauges is between 10.6 and . Test-time heat fluxes have been measured with the new gauges on a sharp wedge model and a blunt-nosed wedge model in flows with total enthalpies of over multiple shots in an expansion tunnel. Stagnation point measurements exceeded . Experimentally measured heat fluxes are shown to agree with surface-junction coaxial thermocouples and an empirical correlation on the stagnation point.