A Construction Method of Rotating Turbulence Pans Model Driven by Vortex Feature

Abstract

The invention discloses a rotational turbulence PANS model driven by vortex characteristics. The realization process mainly comprises the following steps: introducing a pseudo-vortex degree to distinguish the motion form of a local fluid; calculating a vortex characteristic index to realize self-adaptive tracking of flow field characteristics; calculating a turbulence kinetic energy filtering factor and a dissipation rate filtering factor based on an eddy characteristic index in the rotational turbulence; calculating the vortex-viscous damping of the near-wall area to ensure the rotating turbulence consistency condition; and taking a classical RNG k-epsilon model as a substrate, and determining a new PANS model by correcting a transport equation and an empirical coefficient. According to the rotational turbulence PANS model driven by vortex characteristics, vortex characteristic driving parameters are introduced; the efficient analysis of the rotating turbulence can be realized only bylinking the vortex characteristics of the flow field; and dynamic adjustment of turbulence energy and dissipation rate filtering factors does not need to be related to the spatial scale of the grid,and the requirement of numerical simulation for the grid can be effectively reduced, and the calculation precision and the calculation efficiency can be better considered, and a new thought can be provided for efficient calculation of rotational turbulence in fluid machinery.

Description

technical field [0001] The invention relates to the field of calculation of engineering fluid mechanics, in particular to a method for constructing a rotating turbulent PANS model driven by vortex characteristics. Background technique [0002] Rotating turbulent flow is a typical flow phenomenon in many fluid machines such as water turbines, water pumps, steam turbines and compressors. Affected by factors such as strong rotation, large curvature, and multiple walls, the rotating turbulent flow in fluid machinery exhibits characteristics such as nonlinearity, strong transient, high pulsation, and wide scale. Considered to be one of the most complex flows. Therefore, the development of a turbulence model that can balance calculation accuracy and calculation efficiency has always been a research hotspot in the field of engineering computational fluid dynamics. [0003] In recent years, the PANS model has been increasingly used in fluid machinery as a hybrid method that can ac...

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Problems solved by technology

However, the dynamic calculation of the current PANS model basically depends on the relative size of the grid space scale and Taylor scale, that is, it is related to the grid conditions of the calculation domain while connecting the flow field characteristics, which will raise the number and quality of grids. Certain requirements, which in turn limit the efficiency and robustness of numerical calculations

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