CALCULATION OF THE FLOW FIELD NEAR THE ABSORBING SURFACE USING THE KINETIC-HYDRODYNAMIC MODEL AND INCREASING ITS COMPUTATIONAL EFFICIENCY

Abstract

Aim of the work is to develop a physical and mathematical model that combines the kinetic and hydrodynamic description of the flow, and to increase its computational efficiency. Methodology. An analytical research method was used in the work. To study the properties of the resulting model, the method of a numerical experiment was used. Results. The calculation results show that the combined kinetic-hydrodynamic model (KHM) makes it possible to physically adequately describe the processes occurring in the transition region of the gas medium flow. There are no discontinuities in the derivatives of the gas parameters in the region where the model components are stitched together. The KHM model allows setting boundary conditions on absorbing surfaces. The values of such an integral characteristic as cx(α), calculated by the KGM, are in satisfactory agreement with the results of calculations by the model kinetic equation. Research implications. When calculating relatively dense gases (Kn = 0,01), the model allows to reduce the memory consumption of the computing device by about three orders of magnitude and the processor time by two orders of magnitude compared to the model kinetic equation. The developed model can be used in a wide range of Knudsen numbers.