Judgment method for boundary layer transition of hypersonic aircraft

Abstract

The invention provides a judgment method for boundary layer transition of a hypersonic aircraft. The method comprises the steps of determining a transition position of the surface of the aircraft based on early-stage test data; obtaining an orthogonalized laminar flow field of the surface of the aircraft in a corresponding test state, and obtaining N-value distribution of the surface of the aircraft by adopting an improved e-N method considering a transverse flow mode; and in combination with the transition position of the surface of the aircraft, determined based on the test data, determiningan N value N0 for triggering the transition and judging the transition position of the target aircraft. According to the method, based on the test data, a three-dimensional characteristic of the flowfield of the hypersonic aircraft in a lifting body/waverider shape is considered; during the adoption of the e-N method for integration, in addition to consideration of disturbance waves of a secondmode, disturbance waves of the transverse flow mode with the lower frequency are considered; the transition criterion N0 capable of accurately predicting the transition position is obtained; and the effective judgment method is provided for accurately predicting the boundary layer transition of the hypersonic aircraft in the lifting body/waverider shape.

Description

technical field [0001] The invention belongs to the technical field of aircraft boundary layer stability analysis and transition prediction, in particular to a method for judging the boundary layer transition of a hypersonic aircraft, in particular to a method based on flight / test data applied to a lifting body / waverider hypersonic speed Transition judgment method of aircraft boundary layer. Background technique [0002] During the flight test of a hypersonic vehicle (hereinafter referred to as the vehicle), there are two flow states, laminar flow and turbulent flow, on the surface of the vehicle. The difference in the flow state leads to the difference in the lift, drag, surface heat flow, engine performance and inlet start performance of the aircraft. In the present invention, the flow process from laminar flow to turbulent flow is defined as transition. Accurately predicting the transition position of the aircraft surface is the key to the aircraft design and determines...

AI Technical Summary

Problems solved by technology

However, for hypersonic vehicles with complex shapes such as lifting bodies/waveriders, due to the strong thre

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