Radial Heat Flux Profile Measurements in Plasma Flows of Arc-heated Wind Tunnel Using an Impulse Response Identification Approach

Abstract

Accounting the difficult fabrication of a null-point calorimeter, a modified heat flux sensor and its probe are designed for radial heat flux profile measurements in plasma flows of arc-heated wind tunnel. To improve its accuracy and extend its effective measuring time, a dynamical heat flux measurement method with a fixed-length, identified impulse response is present. Firstly, the impulse response of the modified heat flux sensor is identified through calibration setup; then, its dynamical heat flux estimation model is obtained with respect to the temperature data and the identified impulse response. The validation calibration tests show that its measurement accuracy and effective measurement time are improved without sacrificing transient response characteristic. Finally, the radial heat flux profile in plasma flows is measured through scanning mode with the identified heat flux probe. Its measurement results at the corresponding position agree with that of slug calorimeter.