Method of laser energy injection to improve intake air capture of ramjet

Abstract

The invention provides a method for raising the air inflow yield of a ramjet through the technology that laser energy can deposit and puncture a flow field to form quasi-state waves. The method comprises pre-estimating the position of front oblique shock waves of a ramjet, shaping a laser beam into a laser sheet, shaping quasi-state waves, and raising the air inflow yield. The method comprises S1, solving a NS equation to numerically simulating a flow field, or carrying out a wind tunnel test according to the Mach and Reynolds similar criterion to determine whether the air inflow yield of an air intake duct of the ramjet reaches up to the designed value and the position of a front oblique shock waves, S2, shaping a laser beam into a laser sheet through combination of a plurality of reflectors and lenses, S3, optimizing the value, position and frequency of laser energy to form quasi-state waves, and S4, changing the flowing direction of an upstream the lip of the air intake duct under the function of interaction of the quasi-state waves and the front oblique shock waves, to deflect and compress a coming flow which originally can be spill out into an internal compression segment of the air intake duct.

Description

technical field [0001] The invention belongs to the field of main control flow control, and relates to a device for increasing the air intake capture amount of a ramjet engine of supersonic and hypersonic aircraft. Background technique [0002] The supersonic or hypersonic ram jet inlet relies on the oblique shock wave of the precursor to capture and compress the airflow. The ideal geometric configuration is a shock seal, that is, the oblique shock wave of the precursor compression is collected on the lip, and the reflected wave is incident on the inlet shoulder. department. The shock angle is determined by the Mach number, so at flight Mach numbers lower than the design Mach number, spillover occurs and air capture is reduced. In order to avoid the resulting reduction in engine performance, a variable-geometry intake port can be used, but the mechanical system for changing the geometric configuration is relatively complicated. Another possible method is to inject or extra...

AI Technical Summary

Problems solved by technology

[0004] The domestic and foreign work on energy injection to control the intake air capture of ramjet engines has proved the feasibility of this method, but currently, a laser energy deposition guidance scheme with strong engineering applicability has not been proposed for the laser energy injection method

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