Multi-scale flow control antifriction device and manufacturing method

Abstract

The invention relates to a multi-scale flow control friction resistance reducing device and a manufacturing method, and belongs to the technical field of flow control. Strip-shaped plasma vortex generators and groove wall surfaces are sequentially and alternately arranged in the flow direction, and the strip-shaped plasma vortex generators form a flow direction vortex array arranged in the spanwise direction; irregular spanwise movement of a large-scale flow structure in a turbulent boundary layer is limited, and friction components caused by the large-scale flow structure under the medium-high Reynolds number are reduced; the wall surface friction resistance caused by a near-wall flow structure in a turbulent boundary layer is reduced by the wall surface of the groove, and a small-scale flow structure in a near-wall area is controlled; and a region for controlling the multi-scale flow structure is formed in the combined action range of the flow direction vortex array generated by the plasma vortex generator and the wall surface of the groove. The irregular movement of the large-scale flow structure in the inner and outer areas of the turbulent boundary layer and the irregular movement of the small-scale flow structure in the near-wall area are jointly controlled, so that the corresponding friction components are reduced, the total resistance is reduced, and the resistance reduction effect is improved.

Description

technical field [0001] The invention relates to the technical field of flow control, in particular to a friction reducing device and a manufacturing method for controlling multi-scale flow structures in a turbulent boundary layer. Background technique [0002] Aerodynamic drag is a necessary price paid by aircrafts when they move at high speed. Among them, the frictional resistance caused by the relative motion of the aircraft surface and the fluid accounts for about 50% of its total aerodynamic resistance. For large aircraft, a large amount of friction is created by the turbulent boundary layers attached to their surfaces. Therefore, the research on friction reduction for the turbulent boundary layer is helpful to significantly reduce the total flight resistance of the aircraft. [0003] Under the given flow conditions and the aerodynamic shape of the aircraft, the reduction of friction is often achieved by controlling the multi-scale flow structure in the turbulent bound...

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Problems solved by technology

[0004] (1) The drag reduction of grooves has strict requirements on the incoming flow conditions. However, in practical applications, the characteristic Reynolds number span is large, and it is often difficult to maintain the optimal drag reduction conditions of grooves in a wide range of time and space. Increased friction occurs over time

[0005] (2) The flow in real working conditions is complex and changeable, and the local flow often does not coincide with the main direction of the groove, so that the actual drag reduction effect is significantly reduced or even the risk of increased drag

At medium and high Reynolds numbers, the large-scale flow structure (size larger than the nominal thickness of the boundary layer) in the outer region of the turbulent boundary layer has an increasingly obvious influence on the near-wall friction. At this time, only by controlling the small-scale flow structure near the wall (size ) to achieve friction reduction effect is relatively limited

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