Variable-Fidelity Euler–Lagrange Framework for Simulating Particle-Laden High-Speed Flows

Abstract

The current work presents a simulation framework for modeling high-speed flows with suspended solid particles using the point-particle discrete element method. The dispersed particle phase is treated in a Lagrangian manner, whereas the dynamics of the surrounding carrier fluid are determined by solving the compressible Navier–Stokes equations in the Eulerian frame. Additionally, a variable fidelity paradigm is adopted with the ability to model one-, two-, and four-way coupling between the dispersed and carrier phases depending on the desired levels of physical realism. Particle mesh-localization is performed using mesh-connectivity information, which also simplifies boundary conditions enforcement, parallelization, and the backcoupling of particle-induced source terms to the carrier fluid. A time-driven hard-sphere approach is employed to accelerate calculations for particle–particle collisions. The particle solution methodology in conjunction with the unstructured, finite-volume US3D flow solver is used to simulate a variety of multiphase flows. These include a series of verification tests and the first-of-its-kind numerical investigation into elevated levels of surface heat flux experienced by the Mars 2020 spacecraft if planetary entry through the Martian atmosphere were to occur during a major dust storm.