Investigation of calibration method for hot-wire probe in compressible flow

The output of hot-wires is related to fluctuation velocities, and is closely related to fluid temperature and density when a hot-wire technology is used to measure turbulence intensity in compressible fluid. Therefore, hot-wire probes should be accurately calibrated before being used in a calibration facility, which has similar characteristics as those in high speed compressible fluid. In this paper, a calibration method for hot-wire probes in compressible flow is proposed, and a mathematical model of hot-wires for calibrations and measurements is established. Calibration experiments of hot-wire probes are conducted, and an experiment of turbulence intensity measurements is carried out in a wind tunnel with self-building hot-wire calibration. The result indicates that, the calibration method is feasible, and the mathematical model is reasonable and reliable. The calibration accuracy for hot-wire probes is high, and the results of turbulence intensity measurements are credible. The engineering requirements for hot-wire probe measurements in compressible flow are basically satisfied.