An experimental investigation was made of two problems that are fundamental to the application of hot wire anemometry in a supersonic flow. First, the equilibrium temperature of a wire in supersonic flow was established as a function of the flow parameters. Second, the heat loss law for a heated wire in a supersonic flow was determined. In the latter case it was shown that the heat loss, represented by a Nusselt number, is a function of Reynolds number only, with the temperature loading as a parameter. There is no Mach number effect from M = 1.80 to M = 4.54, the range of the present experiments.
The results show that the hot wire should be a satisfactory instrument for the measurement of both mean values and fluctuations of the mass flow and the stagnation temperature.