1 research outputs found
Positivity-preserving finite difference WENO scheme for Ten-Moment equations with source term
We develop a positivity-preserving finite difference WENO scheme for the
Ten-Moment equations with body forces acting as a source in the momentum and
energy equations. A positive forward Euler scheme under a CFL condition is
first constructed which is combined with an operator splitting approach
together with an integrating factor, strong stability preserving Runge-Kutta
scheme. The positivity of the forward Euler scheme is obtained under a CFL
condition by using a scaling type limiter, while the solution of the source
operator is performed exactly and is positive without any restriction on the
time step. The proposed method can be used with any WENO reconstruction scheme
and we demonstrate it with fifth order accurate WENO-JS, WENO-Z and WENO-AO
schemes. An adaptive CFL strategy is developed which can be more efficient than
the use of reduced CFL for positivity preservation. Numerical results show that
high order accuracy and positivity preservation are achieved on a range of test
problems