Base pressure and temperature behind axisymmetric bodies with interaction between a jet and a supersonic stream

Abstract

tions were not made in this work, but an attempt was made only at a qualitative analysis of the effect of some of the parameters on the base pressure. A more thorough investigation of flow in the base region in the presence of a single reactive jet is described in [4]. Here a function of the errors was used as the profile of the velocities; the value of the parameter of association was assumed equal to unity. An investigation was made of the interaction between a jet and a stream, homogeneous in composition but differing with respect to temperature. A comparison between calculated and experimental data attests to their satisfactory agreement with large values of the ratio of the radii of the nozzle and the base cross section. The present article expounds a method for calculating the base pressure and the base temperature behind axisymmetric bodies with an outlet cross section in supersonic streams in the presence of a single reactive jet flowing out of the base cross section. The method is based on the use of some of the premises of the Korst theory and is a further development of the methods of [6, 7]. Here there are considered only conditions of the outflow of the jet in a not fully expanded state, similar to the conditions with which the breakaway of the flow from the trailing edge of the body takes place. It is shown that, depending on the concentrations of the reacting components, the burning-out process (within the framework of a model of diffusional combustion) can take place either in the zone of mixing of the jet or in the zone of mixing of the stream. In the partial ease where the mass amounts of the reagents entering the base region are in a stoichiometric ratio, the reaction takes place ha the base region. The article gives the results of calculations for flow conditions with combustion and without combustion. In the latter case, the calculated data are compared with the experimental. 1. Statement of Problem Let us consider axisymmetrie flow around a body located in a steady-state supersonic stream with a zero angle of attack, ha the presence of a single supersonic unexpanded jet, issuing from the base cross section of the body. We limit the discussion to flow conditions with which the breakaway of the flow takes place from the trailing edge of the base cross section. A schematic diagram of this kind of flow is shown on Fig. 1. On this figure I ts the jet; II is the base region; IH is the stream; M is the Maeh number.