Direct Simulation Monte Carlo(DSMC)solves the Boltzmann equation with large Knudsen number.The Boltzmann equation generally consists of three terms:the force term,the diffusion term and the collision term.While the fi...Direct Simulation Monte Carlo(DSMC)solves the Boltzmann equation with large Knudsen number.The Boltzmann equation generally consists of three terms:the force term,the diffusion term and the collision term.While the first two terms of the Boltzmann equation can be discretized by numerical methods such as the finite volume method,the third term can be approximated by DSMC,and DSMC simulates the physical behaviors of gas molecules.However,because of the low sampling efficiency of Monte Carlo Simulation in DSMC,this part usually occupies large portion of computational costs to solve the Boltzmann equation.In this paper,by Markov Chain Monte Carlo(MCMC)and multicore programming,we develop Direct Simulation Multi-Chain Markov Chain Monte Carlo(DSMC3):a fast solver to calculate the numerical solution for the Boltzmann equation.Computational results show that DSMC3 is significantly faster than the conventional method DSMC.展开更多
A new class of supersonic nonequilibrium flows is studied on the basis of solving the Boltzmann andmodel kinetic equations with the aim to consider new nonlinear structures in open systems and to study anomalous trans...A new class of supersonic nonequilibrium flows is studied on the basis of solving the Boltzmann andmodel kinetic equations with the aim to consider new nonlinear structures in open systems and to study anomalous transfer properties in relaxation zones.The Unified Flow Solver is applied for numerical simulations.Simple gases and gases with inner degrees of freedom are considered.The experimental data related to the influence of the so-called optical lattices on the supersonic molecular beams are considered and numerical analysis of the nonequilibrium states obtained on this basis is made.The nonuniform relaxation problem with these distributions is simulated numerically and anomalous transport is confirmed.The conditions for strong changes of the temperature in the anomalous transfer zones are discussed and are realized in computations.展开更多
文摘Direct Simulation Monte Carlo(DSMC)solves the Boltzmann equation with large Knudsen number.The Boltzmann equation generally consists of three terms:the force term,the diffusion term and the collision term.While the first two terms of the Boltzmann equation can be discretized by numerical methods such as the finite volume method,the third term can be approximated by DSMC,and DSMC simulates the physical behaviors of gas molecules.However,because of the low sampling efficiency of Monte Carlo Simulation in DSMC,this part usually occupies large portion of computational costs to solve the Boltzmann equation.In this paper,by Markov Chain Monte Carlo(MCMC)and multicore programming,we develop Direct Simulation Multi-Chain Markov Chain Monte Carlo(DSMC3):a fast solver to calculate the numerical solution for the Boltzmann equation.Computational results show that DSMC3 is significantly faster than the conventional method DSMC.
基金This research was supported by the Project No.14 of the Presidium of the Russian Academy of Sciences.
文摘A new class of supersonic nonequilibrium flows is studied on the basis of solving the Boltzmann andmodel kinetic equations with the aim to consider new nonlinear structures in open systems and to study anomalous transfer properties in relaxation zones.The Unified Flow Solver is applied for numerical simulations.Simple gases and gases with inner degrees of freedom are considered.The experimental data related to the influence of the so-called optical lattices on the supersonic molecular beams are considered and numerical analysis of the nonequilibrium states obtained on this basis is made.The nonuniform relaxation problem with these distributions is simulated numerically and anomalous transport is confirmed.The conditions for strong changes of the temperature in the anomalous transfer zones are discussed and are realized in computations.
