Development and experimental analysis of circular foil pressure-heat flux gage

Based on the demand of heat flux measurement in the continuous test of vehicle changing orbit, the circular foil pressure-heat flux gage that also can get pressure is developed on the basis of the traditional Gardon gage. The thermal radiation calibration test, the different plate comparison tests in the arc-heated wind tunnel, and numerical calculation analysis are carried out. The results show that the new circular foil pressure-heat flux gage can simultaneously get heat flux and pressure at the same point of the plate model in the multistate continuous arc-heated wind tunnel test. Repeatability accuracy of heat flux and pressure measurement are about 3.6% and 1.9% respectively. Compared with the slug calorimeter, the heat flux value measured by the circular foil pressure-heat flux gage is lower than 14.7%. There are two main reasons for the discrepancy. On one hand, the gage sensitivity coefficient decreases in the convective measurement environment; on the other hand, the incident heat flux of the gage decreases because the temperature of the constantan foil is relatively high so that a local hot spot is formed. Finally, some suggestions for the use of the new circular foil pressure-heat flux gage and traditional Gardon gage are given.