Data Reduction Methodology for Fast-Response Schmidt-Boelter Heat-Transfer Gages

Transient heat-transfer data have recently been obtained in hypersonic wind tunnels at the Arnold Engineering Development Center (AEDC) with miniaturized fast-response Schmidt-Boelter gages. These sensors have time constants in the 10- to 15-msec range, but have response characteristics that are usually less than first-order. This presents a requirement for a general data reduction method to prevent degradation of the accuracy of the experimental data. A consistent nonambiguous data reduction methodology for fast-response Schmidt-Boelter heat-transfer gages is presented which is easy to implement in an algorithmic fashion. Timewise correction of measured Schmidt-Boelter gage heat flux is no more difficult than that involved in a classical first-order system (Gardon gage), and only involves the determination of a characteristic time measure of the integrated energy deficiency inherent in the gage response. This characteristic time measure is easily determined from the gage response characterization to a step input heat flux by numerical integration of the response versus time data.