Reconstruction of the Supersonic Underexpanded Jet Flow Parameters by the Velocity and Total Pressure Fields Measurements Results

摘要

An experimental investigation of the structure of axisymmetric nonisobaric air jet exhausting from the convergent nozzle (Witoszynski profile) with the Mach number in the nozzle exit M_a = 1 and the pressure ratio n = 4.75 is performed. Two types of measurements were used: contactless panoramic laser PIV method and flow field probing using Pitot. Distributions of flow parameters in the diametrical plane containing about 10~4 measured values are experimentally obtained. The combined use of the received data made it possible by solving the energy conservation equation to find the distribution of the main gas-dynamic parameters of the jet flow in this plane - temperature, Mach number, static pressure, density. On the example of the considered task it is shown that the given method can be useful for the study of the detailed shock-wave structure of high-speed underexpanded jet flows.