INVESTIGATION OF INFLUENCE OF SOME ARTIFICIAL VISCOSITY FORMS ON “ENTROPY TRACE” CHARACTER FOR NUMERICAL SOLUTION OF GASDYNAMICS EQUATIONS
A. M. Stenin, E. A. Solov’eva VANT. Ser.: Mat. Mod. Fiz. Proc 2008. Вып.1. С. 3041.
The paper considers the problem of errors reduction for values of quantities in entropy trace domain originating in computations of Lagrangian gasdynamics problems conducted with the help of difference schemes of shock waves endtoend computation. Artificial mass diffusion, artificial impulse diffusion and artificial total energy diffusion are conservatively entered into gasdynamics equations set in Euler coordinates. Formulas for velocity of artificial mass diffusion in continuity equations and for artificial viscosities in motion and energy equations in Lagrangian coordinates are derived from this equations set. In the case of cylindrical and spherical symmetry of flows tensorial artificial viscosity similar to physical viscosity is entered to the motion equation instead of scalar viscosity. Methods of modification of obtained viscosity system by means of Hugoniot conditions on shock wave are considered which improve computation results in entropy trace domain. Results of conducted test computations show high efficiency of new viscosity system concerning reduction of entropy trace for numerical solution of Lagrangian gasdynamics equations.
