A positivity preserving strategy for entropy stable discontinuous Galerkin discretizations of the compressible Euler and Navier-Stokes equations

High-order entropy-stable discontinuous Galerkin methods for the compressible Euler and Navier-Stokes equations require positivity of thermodynamic quantities in order to guarantee their well-posedness. In this work, we introduce a limiting strategy discretizations constructed by blending high solutions with low positivity-preserving discretization. The proposed discretization is semi-discretely entropy stable, preserving equations. Numerical experiments confirm accuracy robustness strategy.