Constant temperature hot-wire anemometer practice in supersonic flows

Abstract

The performance of a constant-temperature inclined hot-wire in a supersonic flow is critically examined. It is shown that empirical heat transfer correlations commonly used for calibrating hot wires in subsonic flow cannot be used when the flow is supersonic. Calibration and measurement procedures appropriate to supersonic flow are suggested, together with the possible limits on their validity. The instrument was used to measure the mass-weighted Reynolds shear stress $\overline {\left( {\varrho u} \right)\prime v\prime }$ in a zero pressure gradient Mach 2.9 turbulent boundary layer. A comparison with the available data suggests good agreement, as long as the normal Mach number remains supersonic under all conditions.