ИСТИНА

This study is devoted to the comparison of continuous and particle-based approaches for two-dimensional numerical simulation of the gas flow transition regime. Regularized 13-moment Grad’s set of equations (R13) is used as continuous mathematical model and Unified Gas-Kinetic Scheme (UGKS) is used as parti-cle-based method. The variant of explicit high resolution Godunov scheme with linear flow parameter reconstruction is chosen for numerical solution of the R13 set of equations. Five so-called kinetic boundary conditions are taken as a base of mathematical model of isothermal solid wall. The complete set of the wall boundary conditions is obtained by an approximation of the selected subset of the R13 bulk equations. The resulted set of nonlinear equations for the wall is solved with Newton’s numerical method. Our implementation of the UGKS follows [3,4] in the basic details, and allows to calculate continuous and rarefied flows in geometrically complex regions. Except well-known test cases, some complex shape micro device gas flows are used as examples of appli-cation of both approaches for various gas flow regimes (from continuous to moderately rarefied). The applicability of the R13 set of equations for mathematical modeling of transition gas flow regime in micro scale devices was confirmed due to comparison with UGKS and other numerical results. There is a good coincidence of the results of both approaches when the Knudsen number is smaller than 0.5 (Kn<0.5).