Meshless particle method for analyzing trapped air mass-containing transient pipe flow

Abstract

The invention discloses a meshless particle method for analyzing trapped air mass-containing transient pipe flow. The meshless particle method comprises the following steps of (1) initializing relevant variable and particle information; (2) carrying out iterative computation, namely circulating a time variable, circulating particles, calculating pressure information of fluid particles of the initialized particles and updating the pressure information of the fluid particles, the pressure information of upstream virtual particles, speed information of the fluid particles, speeds of upstream and downstream virtual particles, particle positions and corresponding pressure and speed information and the pressure information of downstream virtual particles; and (3) outputting the result. A water hammer equation under a lagrange system is solved by adopting a smoothed particle hydrodynamics method; the influences caused by movement of a gas-liquid interface and weak compressibility of water are fully considered; various errors caused by interpolation and gas-liquid interface tracking technologies are reduced; and the trapped air mass-containing transient pipe flow can be more conveniently simulated on the premise of meeting the numerical precision.

Description

technical field [0001] The invention relates to the technical field of fluid mechanics, in particular to a meshless particle method for analyzing the transient flow of a pipeline containing trapped air mass. Background technique [0002] The problem of transient flow in pipes with trapped air mass can be solved by rigid column theory and characteristic line method or other grid methods without considering the elasticity of water body and the movement of gas-liquid interface. However, in many cases, the elasticity of water body and the movement of gas-liquid interface The movement of the liquid interface must be considered at the same time. The above methods usually cause complex calculation problems due to the need to track the movement of the interface, and the calculation accuracy also decreases with the accumulation of interpolation errors. The meshless particle method based on the Lagrangian particle model can fully consider the movement of the gas-liquid interface and t...

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Problems solved by technology

[0002] The problem of transient flow in pipes with trapped air mass can be solved by rigid column theory and characteristic line method or other grid methods without considering the elasticity of water body and the movement of gas-liquid interface. However, in many cases, the elasticity of water body and the movement of gas-liquid interface The movement of the liquid interface must be considered at the same time. The above methods usually cause complex calculation problems due to the need to track the movement of the interface, and the calculation accuracy also decreases with the accumulation of interpolation errors

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