Research on stagnation point heat flux measurement methods of the sharp leading edge model in arc-heated wind tunnel test

Based on the demand of stagnation point heat flux measurement on the sharp leading edge model in the arc-heated wind tunnel test, a kind of curved null-point calorimeter and the corresponding heat flux measurement methods are developed for a leading edge model with radius R = 2 mm. Radiation heat flux calibration and arc-heated wind tunnel tests are carried out for the leading edge model equipped with 3 curved null-point calorimeters and 2 pressure ports. The results show that the newly developed curved null-point calorimeter can obtain the temperature curve of the typical one-dimensional semi-infinite model. The heat flux curve calculated by the temperature curve is stable and the heat flux values are linear under different states. The correction coefficient should be obtained by heat flux calibration before each null-point calorimeter is used. Heat flux and pressure of the sharp leading edge model are measured in four different flow states of the arc-heated wind tunnel test. In the same flow state, the maximum deviation of heat flux measured by 3 curved null-point calorimeters in the leading edge model is less than 10%, and the maximum deviation of pressure measured by 2 pressure ports is less than 5%. The maximum deviation between the mean value of 3 curved null-point calorimeters and the numerical value is less than 9%, and the maximum deviation between the mean value of 2 pressure ports and the numerical value is less than 8%. It indicates that the newly developed curved null-point calorimeter and heat flux measurement methods have good measurement accuracy and can be used to measure stagnation point heat flux of the leading edge model with radius R = 2 mm.