Constant-Temperature and Constant-Voltage Anemometer Use in a Mach 2.5 Flow

摘要

In summary, a systematic comparison of constant-temperature anemometer (CTA) and constant-voltage anemometer (CVA) fluctuation measurements in supersonic flow is made. The same hot wire is operated at the same locations under the same conditions with both systems. A posttest software correction is applied to the fluctuation measurements in both systems. For the CTA the frequency response is obtained; this is then used to correct the measured data for the bridge's dynamic behavior. In the case of the CVA, the in situ time constant of the hot wire is measured; the measured time constant is then applied to CVA measurements obtained with a fixed compensation. The software-corrected CTA and software-corrected CVA spectra are in very good agreement when the signal-to-noise ratio is above unity for both systems. This demonstrates that accurate large-bandwidth CTA measurements are possible without the need for either a 1:1 bridge or a time-consuming adjustment procedure.