Cavity multi-field coupling equation of cavity and boundary condition establishing method

Abstract

The invention discloses a cavity multi-field coupling equation and a boundary condition establishing method. A cavity multi-field coupling boundary condition is established based on a cavity flow control equation, a cavity noise control equation and a cavity structure vibration control equation. The method has the advantages that the method starts from basic principles of hydrodynamics, aeroacoustics and structural dynamics, and establishes the multi-field coupling equation of cavity flow / vibration / noise, and can ensure the correctness of the established equation fundamentally; based on the coupling characteristics of the cavity flow, vibration and noise, the cavity multi-field coupling boundary condition is established, which is beneficial for grasping the essence and key parameters of cavity multi-field coupling problems, the method has positive guidance for experimental and numerical researches of cavity type problems, and the research efficiency can be improved; the cavity multi-field coupling equation and the cavity boundary conditions are established in consideration of vibration problems of a cavity structure, which makes a research model closer to actual cavity problem, thereby improving the simulation ability of the cavity type problems.

Description

technical field [0001] The invention relates to the interdisciplinary technical fields of fluid mechanics, aeroacoustics and structural dynamics, and specifically relates to a cavity multi-field coupling equation and a method for establishing boundary conditions. Background technique [0002] Cavity flow is a typical unsteady and nonlinear flow phenomenon, especially under the condition of high-speed incoming flow, the gas flow velocity in the cavity is low, and the gas flow velocity outside the cavity is high, and gas with different flow velocities will form in the opening area of ​​the cavity. The transition layer, which is called the shear layer. When the shear layer hits the wall surface of the cavity, flow-induced oscillations are prone to occur in the cavity, resulting in high-intensity aerodynamic noise, and the high-intensity noise environment easily leads to fatigue of the cavity structure, and changes the flow field and sound field of the cavity. The boundary cond...

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Problems solved by technology

[0003] At present, the complexity of cavity flow / vibration / noise multi-field coupling problems is significantly higher than that of cavity single-physics problems, and cavity multi-field coupling equations and coupling boundary conditions are rare. Based on fluid mechanics, aeroacoustics, The basic principles of structural dynamics, the systematic establishment of equations for cavity multi-field coupling problems, and the proposal of cavity multi-field coupling boundary conditions are of great significance for further improving the research ability of cavity problems and expanding the scope of research, and can also make up for traditional research methods. These deficiencies are mainly reflected in three aspects. One is the lack of means to establish cavity flow / vibration / noise multi-field coupling equations, which is not conducive to grasping the main contradiction of cavity multi-field coupling problems, thus increasing research costs and reducing Second, the lack of reasonable and effective cavity multi-field coupling boundary conditions may lead to a significant increase in the error of numerical calculation results; third, ignoring the influence of the cavity wall structure increases the deviation between the research problem and the real situation, reducing the The ability to guide practical problems from experimental and numerical calculation results

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