Numerical simulation of wall heat flux in supersonic weakly ionized gas flow

The paper presents results of numerical simulation of laminar and turbulent weakly ionized plasma flows around model bodies under MHD interaction.Numerical investigations have been carried out of supersonic MHD flow of weakly ionized nitrogen plasma around model bodies (spherically blunted cylinder, truncated cylinder, and cone-cylinder lay-outs) at conditions of experiments on the Big Shock Tube (BST) of the Ioffe Institute of Russian Academy of Sciences. The purpose of the investigations was verification of a mathematical model and algorithm as well as analysis of predominant factors determining the MHD impact on the flow structure and thermal load on the model. The effect of the magnetic field induced by the coil installed in the model on the plasma flow was investigated and the efficiency of the MHD interaction was estimated. To enhance the efficiency of the MHD interaction a surface electric discharge was arranged between an electrode installed on the model nose and a ring coaxial electrode installed in the vicinity of the cone-cylinder conjugation. In the magnetic field induced by the coil the discharge rotates producing a domain of high plasma electric conductivity near the cone surface. Comparison of the predictions with experimental data obtained on the BST was presented.Thus the considered system is typical muliphysics and multiscale one involving interaction of supersonic flow with the electromagnetic field, description of large eddies evolution, turbulence model for subgrid scale, and effects of localized electric discharge. Investigations showed that at conditions under study the predominant factors of MHD impact on weakly ionized plasma flow around the body determining the flow structure are both the ponderomotive force and the Joule heating.