Shock wave variable step size solving method based on B-spline mapping function material point method

Abstract

The invention provides a shock wave variable step size solving method based on a B-spline mapping function material point method. The method comprises the steps: firstly, establishing a B-spline mapping function; then, establishing a shock wave flow field model, and discretizing the shock wave flow field; giving an initial condition and a boundary condition of the shock wave flow field, and setting a calculation total length; calculating the time step length of the current calculation step according to the stability condition; solving a shock wave problem by using a material point method; andfinally, carrying out visualization processing on the shock wave flow field. According to the method provided by the invention, the problem of difficulty in processing a convection term in an Euler method and the problem of grid distortion in a Lagrange method can be avoided; and compared with a traditional standard substance point method and a traditional GIMP method, the method has the advantages that oscillation can be better suppressed, stability and robustness are higher, calculation efficiency is higher, and a new method can be provided for solving shock waves in engineering.

Description

technical field [0001] The invention belongs to the technical field of shock wave flow field solution methods, in particular to a shock wave variable step size solution method based on a B-spline mapping function material point method. Background technique [0002] Shock wave is the propagation of a discontinuous peak in a fluid medium, resulting in a step change in the physical properties of the flow field such as pressure, temperature, and density. It widely exists in engineering, such as train shock waves formed when high-speed trains are running, mine blasting, explosion-proof vehicles, etc., which may cause casualties and equipment damage. With the development of computer technology, CFD technology has been gradually applied to the simulation of shock waves. By numerically calculating the propagation process of shock waves, its disturbance effect on the flow field can be obtained, which can provide calculation parameters for the calculation of the aerodynamic load of it...

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Problems solved by technology

And only in the initial stage of the calculation, the stable step size is calculated based on the initial conditions. For the shock wave problem, the local sound velocity in each part of the flow field will change greatly due to the impact of the shock wave. It is very likely that the stability condition is no longer satisfied in , leading to computational divergence

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