Strong coupling solid-liquid multiphase flow numerical simulation method

Abstract

The invention provides a strong coupling solid-liquid multiphase flow numerical simulation method, which comprises the following steps: determining stress characteristics of a solid phase and a liquid phase through physical and mechanical analysis, and writing the stress characteristics of the solid phase and the liquid phase into a numerical model; acquiring topographic data and object source data of a mountain land to be measured, and converting (x, y, z, h) four-dimensional grid data through grid coordinates; defining interphase viscous drag force and virtual mass force of a to-be-measured mountain land, obtaining channel starting, movement and accumulation position information of the to-be-measured mountain land, and constructing a conservation vector model, a solid-liquid interphase acting force model, a buoyancy model, a viscous drag force model, a virtual mass force model, a multiphase flow model and a liquid-phase bottom bed frictional resistance model; and carrying out strong coupling solid-liquid multiphase flow numerical simulation. The invention is suitable for a strong coupling mechanical mechanism of multiphase complex substances of different substances, and the problems of ellipse degradation, phase separation, flow state disorder, fluid distortion and the like caused by insufficient interphase acting force coupling in a traditional digital simulation method can be solved.

Description

technical field [0001] The invention belongs to the technical field of mountain disaster prevention and environmental management, and in particular relates to a numerical simulation method for strongly coupled solid-liquid multiphase flow. Background technique [0002] Solid-liquid multiphase flow is a mixed fluid composed of solid-phase particles and liquid-phase fluid. Solid-phase particles and liquid-phase fluid interact with each other, coexist and have a clear interface in motion, which involves fluid dynamics, thermodynamics, heat and mass transfer. It is of great significance to the development and progress of multiphase flow science, the change of ecology and environment, the analysis of mountain disaster prevention and control, and environmental governance. [0003] Nowadays, the numerical simulation of solid-liquid multiphase flow cannot accurately realize the various multiphase complex material fluids involved in the process of mountain disasters. At present, the ...

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Problems solved by technology

[0003] Nowadays, the numerical simulation of solid-liquid multiphase flow cannot accurately realize the various multiphase complex material fluids involved in the process of mountain disasters. At present, the various physical mechanisms of multiphase flow in mountain disasters are not clear, and the numerical simulation methods are too simplified, such as:

[0004] (1) The literature with the patent application number 201710958968.9 discloses a numerical simulation and numerical calculation method for the whole process of debris flow. This method is based on the single-phase NS equation of the Savage-Hunter theory, and the multi-phase flow medium to be simulated is simplified to a single-phase The complex fluid medium is simulated and defined by a set of shallow water wave equations; although it can play a good role in simulation and prediction macroscopically, it cannot consider some of the deep physical mechanisms of solid-liquid coupling due to the simplification of its governing equations (Interphase force, solid and liquid constitutive models, etc.) Therefore, this technology cannot analyze the various physical force mechanisms and dynamic information of multiphase flow in depth, and can only be used for fast macroscopic numerical simulation and inversion. utility; and in this method, the purpose of defining the solid and liquid in the medium is achieved by artificially defining the particle volume concentration, but this ratio is fixed

[0005] (2) In the literature with the patent application number 201811522183.8, a solid-liquid multi-phase dynamic numerical simulation method suitable for debris flow is disclosed. This method independently defines the solid-liquid two-phase equation for the first time, and applies the appropriate and universal The constitutive equation defines the flow state and force characteristics of the solid phase and liquid phase. However, due to the simplicity of calculation, the constitutive equation is simplified as follows. It is assumed that the interphase force is about the effect of viscous drag force, because other stresses are compared with viscous drag force The drag force is relatively small; however, this method has found that the effect of virtual mass force is particularly obvious in many multiphase solid-liquid dense particle flows, and the μ(I) constitutive relation is used as the constitutive relation of the solid-phase particle medium in this method, However, the model μ(I) only considers the frictional resistance and motion characteristics of the particles under the action of inertia, and ignores the influence of liquid phase fluid substances on the solid phase in multiphase flow, which reduces the reliability of the simulation

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