Hanchun Yang | Searcharxiv

arXiv2014

Vanishing Pressure Limit of Solutions to the Aw-Rascle Model for Modified Chaplygin gas

This paper analyzes the vanishing pressure limit of solutions to the Aw-Rascle model and the perturbed Aw-Rascle model for modified Chaplygin gas. Firstly, the Riemann problem of the Aw-Rascle model is solved constructively. A special delta shock wave in the limit of Riemann solutions is obtained. Secondly, the Riemann problem of the perturbed Aw-Rascle model is solved analytically. It is proved that, as the pressure tends to zero, any Riemann solution containing two shock wave tends to a delta shock solution to the transport equations; any Riemann solution containing two rarefaction wave tends to a two-contact-discontinuity solution to the transport equations and the nonvacuum intermediate state in between tends to a vacuum state.

math.AP↗

arXiv2014

Delta-shocks and vacuums in zero-pressure gas dynamics by the flux approximation

In this paper, firstly, by solving the Riemann problem of the zero-pressure flow in gas dynamics with a flux approximation, we construct parameterized delta-shock and constant density solutions, then we show that, as the flux perturbation vanishes, they converge to the delta-shock and vacuum state solutions of the zero-pressure flow, respectively. Secondly, we solve the Riemann problem of the Euler equations of isentropic gas dynamics with a double parameter flux approximation including pressure. Further we rigorously prove that, as the two-parameter flux perturbation vanishes, any Riemann solution containing two shock waves tends to a delta shock solution to the zero-pressure flow; any Riemann solution containing two rarefaction waves tends to a two-contact-discontinuity solution to the zero-pressure flow and the nonvacuum intermediate state in between tends to a vacuum state.

math.AP↗