Numerical Study Of Interaction Between High Speed Gas And Elliptical Column Array

Particle flow is the flow of solid particles.Particle flow exists not only in nature and people's daily life but also in the fields of industrial and agricultural production,energy and environmental protection.Therefore,the study of particle flow and its motion has important sense.High-speed particle flow is an important branch of particle flow.It is a typical compress-ible multiphase flow problem and has important applications in astronomy,natural disasters,industrial safety,medical industry,and national defense.In particle flow systems,most of the experiments are based on spherical particles,but in fact,the particles are usually non-spherical,and ellipsoidal particles are the simplest anisotropic model particles in non-spherical particles.Therefore,it is of great significance to study ellipsoidal particles.In this paper,the direct numerical simulation method based on the stratified multiphase flow model is used to study the early stage of interaction between the plane shock wave and the elliptical column array.The finite volume method(FVM)is used to discretize the govern-ing equations,and the third-order TVD scheme is used for spatial reconstruction.Based on the difference of volume fraction ?g,the interface of each control volume can be reconstructed into three parts:gas-gas,solid-solid and gas-solid,and each part using different flux calculation methods.Specifically,the flux on the surface between gas phase and gas phase is calculated by AUSM+-up approximate Riemann solver,the flux on the surface between gas phase and solid phase is calculated by one-side value,and the flux on the surface between solid phase and solid phase is not calculated.The third-order Runge-Kutta method is used for time advancing.The slip boundary condition is adopted at the gas-solid interface.In this paper,MPI parallelization is applied to perform high-performance calculations.We focus on the influence of the ratio A which is the length of the long axis of the elliptical cylinder cross-section divided by the length of the short axis and the angle ? between the long axis of the elliptical cylinder cross section and the flow direction on the flow field,the distribu-tions of the velocity u,RMS velocity u" and v",kinetic energy,internal energy,and turbulent kinetic energy are analyzed,then we make quantitative analysis of energy in the upstream region of the computational domain,the elliptical column array region and the downstream region.At the same time,the evolution of total internal energy,total kinetic energy and turbulent kinetic energy with dimensionless time t is concerned.The pressure distribution,density distribution and temperature distribution of flow field under different conditions are discussed.We improve the 1-D volume-average model for elliptical columns and seek the appropri-ate artificial effective drag coefficient Cd by fitting the position of the reflected shock and the position of the transmitted shock directly from the direct numerical simulation results and the distribution law of the optimal Cd is discussed.