Second order Implicit-Explicit Total Variation Diminishing schemes for the Euler system in the low Mach regime

TL;DR

This paper develops a new class of implicit-explicit TVD schemes for the Euler system in low Mach regimes, achieving asymptotic stability, high accuracy, and monotonicity preservation across Mach numbers.

Contribution

It introduces a novel implicit-explicit scheme coupling first and second order methods, ensuring stability and accuracy in low Mach number flows, with proven TVD properties.

Findings

Scheme is asymptotically stable with Mach number independent CFL condition.

Method interpolates from first to second order in space and time.

Numerical tests confirm stability, accuracy, and monotonicity preservation.

Abstract

In this work, we consider the development of implicit explicit total variation diminishing (TVD) methods (also termed SSP: strong stability preserving) for the compressible isentropic Euler system in the low Mach number regime. The scheme proposed is asymptotically stable with a CFL condition independent from the Mach number and it degenerates in the low Mach number regime to a consistent discretization of the incompressible system. Since, it has been proved that implicit schemes of order higher than one cannot be TVD (SSP) \cite{GotShuTad}, we construct a new paradigm of implicit time integrators by coupling first order in time schemes with second order ones in the same spirit as highly accurate shock capturing TVD methods in space. For this particular class of schemes, the TVD property is first proved on a linear model advection equation and then extended to the isentropic Euler case. The result is a method which interpolates from the first to the second order both in space and time, which preserves the monotonicity of the solution, highly accurate for all choices of the Mach number and with a time step only restricted by the non stiff part of the system. In the last part, we show thanks to one and two dimensional test cases that the method indeed possesses the claimed properties.