Method suitable for dynamic skin flow control of object

Abstract

The invention relates to a method suitable for dynamic skin flow control of an object. According to the method, a deformable material is attached to the surface of the object, the material and the object can move relative to each other, the object is stretched and contracted by using the mechanical instability of the material, a material flattening surface and a 3D textured surface are transformed, and specifically, when flow separation exists on the surface of the object, the material is stretched, the texture surface with the vortex generator effect is generated, and the flow separation is inhibited; and when flow separation does not exist on the surface of the object, the material is contracted, the surface of the object returns to a smooth state, and the generation of additional resistance is prevented. Compared with the prior art, a passive flow control strategy is adopted by the method, so that the method is high in adaptability and can be used for flow devices such as a cylindrical turbulent flow and a wing; the dynamic flow control strategy is used, so that the expansibility is good; through different degrees of stretching, flow separation control of various variable working conditions can be realized; and a mature passive control strategy is adopted, so that the cost is low, and the reliability is high.

Description

technical field [0001] The invention relates to a flow separation control method, in particular to a method suitable for dynamic skin flow control of objects. Background technique [0002] Flow separation will lead to a rapid increase in the resistance of the aircraft, and the complex flow regime will cause nonlinear changes in the aerodynamic force, which will affect the maneuverability and stability of the aircraft. It is of great engineering significance to take flow control measures to suppress the development of separated flows. Flow control technology includes active flow control technology and passive flow control technology. [0003] Active flow control (such as synthetic jet, electromagnetic control, etc.) is a new research field arising from the intersection of control science and fluid mechanics, mainly applied to shear flow, including free shear layer and boundary layer. In shear flow, the vorticity is generated by the object surface, and the active control of ...

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Problems solved by technology

However, due to the inherently nonlinear nature of synthetic jets, angle, velocity, and frequency are coupled to each other, so selecting optimal control parameters is often difficult and time-consuming

[0005] The research on flow active control under the action of electromagnetic force has the advantages of feasibility, especially the research on closed-loop control, which can be regarded as an important bridge to realize the theory and application of separation active control. In addition to complex and difficult analysis, there are also problems such as low efficiency and electrochemical corrosion

[0006] Active separation and active control are faced with complicated problems, and the flow phenomena are often very complicated. The basic control equation of fluid mechanics——Navier-Stokes (NS) equation is a strongly nonlinear partial differential equation. At present, except for some of the simplest boundary conditions, the actual Problems are often not resolved analytically

[0007] Passive control is flow control without auxiliary energy consumption. Traditional passive flow control strategies such as vortex generators mainly use methods to change the physical model of objects, such as adding flaps to objects. Vortex generators are commonly used in passive flow control. The method can delay the flow separation, but it will not be able to effectively suppress the flow separation in the off-design state, and may even cause additional resistance

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