Khrapov S.S. Numerical Modeling of Two-Dimensional Gas-Dynamic Flows in Multicomponent Nonequilibrium Media
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https://doi.org/10.15688/mpcm.jvolsu.2025.1.5
Igor P. Ermolenko
Candidate of Sciences (Physics and Mathematics), Assistant, Department of Theoretical Physics and Wave Processes,
Volgograd State University
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https://orcid.org/0000-0003-2660-2491
Prosp. Universitetsky, 100, 400062 Volgograd, Russian Federation
Abstract. The dynamics of two-dimensional flows of a multicomponent nonequilibrium gas is considered taking into account relaxation processes, viscosity, thermal conductivity, chemical reactions, external sources of heating and cooling. Based on the numerical gas-dynamic method MUSCL, a computational model has been constructed that allows one to study nonlinear wave structures (weak shock waves, shock-wave pulses, detonation waves) arising in a nonequilibrium medium due to the development of gas-dynamic instabilities (acoustic, thermal, tangential discontinuity of flow velocity) with high spatial resolution. A parallel version of the numerical algorithm has been developed using OpenMP – CUDA – GPUDirect technologies for hybrid computing systems with several graphics processors (multi-GPU), which allows one to significantly increase the computing performance and speed up calculations hundreds of times compared to the versions of the code for the CPU. Numerical modeling of shock-wave structures in a flat two-dimensional channel with a subsonic flow of nonequilibrium gas in the presence of external heating and cooling sources was performed. It was shown that as a result of the interaction of a subsonic flow of nonequilibrium acoustically active gas with a solid wall, shock-wave pulses (SWP) are formed both with a flat front in the direction transverse to the flow and with flexurally deformed SWPs, at the front of which local maxima of gas-dynamic quantities arise due to the growth of acoustically unstable transverse disturbances. These disturbances at the nonlinear stage of evolution form a system of oblique shock waves in the channel, which, repeatedly reflecting from the channel walls and interacting with each other, lead to the formation of a complex irregular flow structure. With an increase in the channel width, the number of local maxima in the distribution of flow parameters at the front of shock-wave pulses increases. Nonlinear wave structures in plane supersonic jets of nonequilibrium vibrationally excited gas, arising as a result of development of Kelvin-Helmholtz instabilities and reflective resonance harmonics of symmetric and antisymmetric jet modes, are investigated. It is shown that taking into account the vibrational nonequilibrium of the medium enhances the instability of the tangential velocity discontinuity in the jet and increases the intensity of shock-wave and vortex structures arising at the nonlinear stage of development of these instabilities. In numerical models of supersonic shear flows of nonequilibrium vibrationally excited gas, new shock-vortex structures of high intensity are discovered, which can be of great importance in practical applications.
Key words: vibrationally excited gas, gas-dynamic instabilities, shock waves, numerical gas-dynamic methods, parallel CUDA algorithms.
Numerical Modeling of Two-Dimensional Gas-Dynamic Flows in Multicomponent Nonequilibrium Media by Khrapov S.S. is licensed under a Creative Commons Attribution 4.0 International License.
Citation in English: Mathematical Physics and Computer Simulation. Vol. 28 No. 1 2025, pp. 60-87
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