In the paper we extend the Multiple-Relaxation-Time （MRT） Lattice Boltzmann （LB） model pro- posed in [Europhys. Lctt., 2010, 90： 54003] so that it is suitable also for incompressible flows. To decrease tile artif...In the paper we extend the Multiple-Relaxation-Time （MRT） Lattice Boltzmann （LB） model pro- posed in [Europhys. Lctt., 2010, 90： 54003] so that it is suitable also for incompressible flows. To decrease tile artificial oscillations, the convection term is discretized by the flux linfiter scheme with splitting technique. A new model is validated by some well-known benchmark tests, including Rie- mann problem and Couette flow, and satisfying agreements are obtained between the sinmlation results and ana.lytical ones. In order to show the merit of LB model over traditional methods, the non-equilibrium characteristics of system are solved. The simulation results are consistent with the physical analysis.展开更多
This paper constructs a new multiple relaxation time lattice Boltzmann model which is not only for the shocked compressible fluids,but also for the unshocked compressible fluids.To make the model work for unshocked co...This paper constructs a new multiple relaxation time lattice Boltzmann model which is not only for the shocked compressible fluids,but also for the unshocked compressible fluids.To make the model work for unshocked compressible fluids,a key step is to modify the collision operators of energy flux so that the viscous coefficient in momentum equation is consistent with that in energy equation even in the unshocked system.The unnecessity of the modification for systems under strong shock is analyzed.The model is validated by some well-known benchmark tests,including thermal Couette flow,Riemann problem.The first system is unshocked and the latter is shocked.In both systems,the Prandtl number effects are checked.Satisfying agreements are obtained between new model results and analytical ones.展开更多
基金The authors would like to sincerely thank S. Succi and C. Lin for many instructive discussions. We acknowl- edge support of National Natural Science Foundation of China （under Grant Nos. 11075021 and 11047020）. A. G. Xu and G. C. Zhang acknowledge support of the Science Foundation of CAEP （Grant Nos. 2012B0101014 and 2011A0201002） and the Founda- tion of State Key Laboratory of Explosion Science and Technology （Grant No. KFJJ14-1M）.
文摘In the paper we extend the Multiple-Relaxation-Time （MRT） Lattice Boltzmann （LB） model pro- posed in [Europhys. Lctt., 2010, 90： 54003] so that it is suitable also for incompressible flows. To decrease tile artificial oscillations, the convection term is discretized by the flux linfiter scheme with splitting technique. A new model is validated by some well-known benchmark tests, including Rie- mann problem and Couette flow, and satisfying agreements are obtained between the sinmlation results and ana.lytical ones. In order to show the merit of LB model over traditional methods, the non-equilibrium characteristics of system are solved. The simulation results are consistent with the physical analysis.
文摘This paper constructs a new multiple relaxation time lattice Boltzmann model which is not only for the shocked compressible fluids,but also for the unshocked compressible fluids.To make the model work for unshocked compressible fluids,a key step is to modify the collision operators of energy flux so that the viscous coefficient in momentum equation is consistent with that in energy equation even in the unshocked system.The unnecessity of the modification for systems under strong shock is analyzed.The model is validated by some well-known benchmark tests,including thermal Couette flow,Riemann problem.The first system is unshocked and the latter is shocked.In both systems,the Prandtl number effects are checked.Satisfying agreements are obtained between new model results and analytical ones.
