Flow Field Control Method of Closed Backflow Channel

Abstract

The invention relates to a closed type return flow channel flow field control method. The closed type return flow channel flow field control method is characterized by comprising the following steps that a, according to design parameter requirements, a hypersonic air inlet duct geometric profile is designed, and the air inlet duct self-starting characteristics are simulated and analyzed; b, basedon different static pressure distribution laws in a compression surface before an inlet of a hypersonic air inlet duct during start / non-start, the pressure difference distribution before and after a shock wave is adopted, and a return flow cavity is formed in the air inlet duct to control a flow field of the air inlet duct; c, the inlet and outlet positions of a return flow channel and cross-sectional parameters of the return flow cavity are subjected to simulated analysis, and the geometric profile parameters of the return flow channel are optimized; and d, the geometric profile parameters ofthe return flow channel are adjusted to determine a final air inlet duct structure. The closed type return flow channel flow field control method can improve the starting ability of the hypersonic air inlet duct at a low Mach number and broadens the range of the working Mach number of the air inlet duct.

Description

technical field [0001] The present invention relates to the design field of intake and exhaust systems of hypersonic aircraft, in particular to a method for controlling the flow field of a closed recirculation channel, which is used to improve the starting ability of a hypersonic inlet at a low Mach number, thereby widening the working Mach number range of the inlet . Background technique [0002] With the increasing demand of countries for information-based operations (communication, surveillance, reconnaissance, intelligence, electronic warfare) and space system offense and defense (long-range rapid and efficient strike platforms, high-speed reusable platforms, and relay platforms for entering and leaving space), the development of adjacent space Hypersonic vehicle technology is becoming increasingly important. The United States, Russia, and European countries have invested a lot of money in the research of hypersonic vehicle technology in near space. Hypersonic vehicle ...

AI Technical Summary

Problems solved by technology

The current measures mainly include the following two types: the first one is to use a variable geometry inlet, and adjust the geometric profile of the inlet (such as a rotating lip) according to different incoming flow conditions, so that the inlet is always in the best position. In this way, the starting performance of the intake port is significantly improved, but the structure of the variable geometry intake port changes greatly during the working process, and the structure is complex, so there are a series of control and sealing problems; the second solution is to use the inlet and outlet The passive flow field control method (such as overflow tank, suction hole, etc.) of the pressure difference between the air inlets can effectively eliminate the separation bag when the inlet is not started, but there is a large flow loss, resulting in a decrease in engine thrust and aircraft resistance. increase

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