A design method of a single-pair supersonic flow vortex generating device

Abstract

The invention discloses a design method of a single-pair supersonic flow vortex generating device. The arc radius of the upper wall surface is specified; the vortex generating section is divided intoa plurality of infinitesimal sections with equal deflection angles, a streamline equation is gradually solved from the end point of the lower wall surface of the transition section to the downstream side by solving a supersonic speed arc outer flow field to obtain an initial lower wall surface profile, and then the displacement thickness of the local boundary layer is superposed to the initial lower wall surface profile to obtain a final lower wall surface profile; And then determining an equivalent expansion angle, and designing upper and lower wall surface profiles of the test window. According to the design method, the supersonic arc outer flow field streamline is used for constructing the vortex generation section, unnecessary background wave systems are prevented from being generatedin the vortex generation section, and control over the strength and the scale of supersonic flow vortex can be achieved only by changing the curvature radius of the vortex generation section. And a feasible test device design method is provided for carrying out test research on the characteristics of supersonic flow vortex in the supersonic ramjet engine and the interference mechanism of the supersonic flow vortex and a downstream shock wave string.

Description

technical field [0001] The invention relates to the field of scramjet aerodynamic experiments, in particular to a design method for generating a supersonic vortex. Background technique [0002] The supersonic flow direction vortex is a common flow phenomenon, especially in the high Mach number inlet, the flow direction vortex is the main flow feature inside it. The generation of supersonic flow vortex is mainly related to the separation flow induced by shock wave / boundary layer coherence. Due to the needs of actual engineering design, the shock wave / boundary layer interference in the inlet is generally strong, so this supersonic flow vortex is very useful as an accessory. Unavoidable. The existence of the flow direction vortex is like a double-edged sword. For combustion, the flow direction vortex can be used to enhance the mixing of airflow and fuel and improve the combustion efficiency; however, for the intake port, the existence of the flow direction vortex may be more ...

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Problems solved by technology

However, the existing theories and test methods are all based on vortex generators. This method can indeed effectively generate flow vortices, but at the same time, it introduces the oblique shock wave generated by the slope of the vortex generator and the expansion of the tail. Fans, the existence of these oblique shock waves and expansion fans will form reflections in the pipeline. When they are incident on the supersonic flow vortex, they will have an irreversible impact on the development, evolution, and rupture of the flow vortex itself. Therefore, if it is necessary to simply study For the flow characteristics of the supersonic flow vortex in the pipeline and the coupling interference between the supersonic flow vortex and the downstream shock train flow, it is not appropriate to use the vortex generator scheme

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