Turbulence model correction method suitable for moving boundary streaming

A turbulence model and boundary technology, applied in the field of hydraulic machinery, can solve the problem of inaccurate numerical prediction of the flow around the dynamic boundary, and achieve the effect of improving the prediction accuracy

Active Publication Date: 2020-01-24
BEIJING INSTITUTE OF TECHNOLOGYGY
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Problems solved by technology

[0004] In order to solve the problem that the numerical prediction of the flow around the moving boundary is not accurate enough in the prior art, the technical problem to be solved by the turbu...

Method used

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  • Turbulence model correction method suitable for moving boundary streaming
  • Turbulence model correction method suitable for moving boundary streaming
  • Turbulence model correction method suitable for moving boundary streaming

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Embodiment 1

[0052] Such as figure 2It is the numerical simulation calculation domain around the dynamic hydrofoil, which includes the dynamic domain and the static domain. The rotation of the hydrofoil is realized by controlling the rotation of the dynamic domain. The hydrofoil is set to rotate at a uniform speed, and the rotational angular velocity is 0.35rad / s ; The inlet is set as a velocity inlet, and the flow rate is 5.5m / s; the outlet is a pressure outlet, and the pressure is 101325pa. The vortex structure judgment criterion adopts omega, and the threshold A is set to 0.52.

[0053] Then calculate the global omega of the initial flow field according to the omega expression, then the filter function f FBM The expression is:

[0054]

[0055] Among them, f v is the dynamic correction factor. Then according to the filter function f FBM , it can be seen that when omega is greater than or equal to 0.52, it is a vortex area, and when omega is less than 0.52, it is a non-vortex ar...

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Abstract

The invention relates to a turbulence model correction method suitable for moving boundary streaming, and belongs to the technical field of hydraulic machinery. The method comprises steps of defininga filtering function fFBM through a vortex structure judgment criterion; dividing the flow field into a vortex region and a non-vortex region based on the filter function fFBM, determining the vortexregion when the vortex structure judgment criterion is greater than or equal to a set threshold A, and determining the non-vortex region when the vortex structure judgment criterion is less than the set threshold A; multiplying the vortex viscosity coefficient mu t of the turbulence model of the vortex region by the dynamic correction coefficient fv, keeping the vortex viscosity coefficient mu t of the turbulence model of the non-vortex region in the original expression, and substituting the vortex viscosity coefficient into the turbulence model equation again to solve the flow field. According to the method, a vortex structure is adopted as a filtering scale, numerical prediction simulation is associated with flow field information, the influence of the dynamic boundary on the vortex viscosity coefficient of the turbulence model is considered, and the streaming prediction precision of the dynamic boundary is greatly improved.

Description

technical field [0001] The invention relates to a turbulent flow model correction method suitable for flowing around a moving boundary, and belongs to the technical field of hydraulic machinery. Background technique [0002] In the study of hydraulic machinery, the additional force generated by the rotation and the disturbance of the static and dynamic components have an important impact on the turbulent flow process, the development of the boundary layer, and the temporal and spatial distribution of the flow structure. It is the focus and difficulty of the research. In the transient process of propeller, turbo pump, hydraulic turbine start-up and shutdown, runaway, load increase and decrease, etc., the transient flow in the transient process will change the effective angle of attack of the lifting surface, and its internal flow is complex and changeable, showing a strong Instability seriously affects the working performance of the device. [0003] For the complex flow aro...

Claims

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Application Information

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IPC IPC(8): G06F30/17G06F119/14
Inventor 吴钦张孟杰刘涛涛黄彪王国玉
Owner BEIJING INSTITUTE OF TECHNOLOGYGY
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