Simulating shock-laden and multiphase flows interface without tracking or dissipation

Shocks and interfaces in multiphase flows are tracked or captured via numerics. We avoid this choice via information geometric regularization, an inviscid treatment at the equation level, not the numerics. This regularization elides grid-level discontinuity formation but maintains long-term solution behavior. The method is robust, accurate, and scalable on canonical test problems. Linear numerics are enabled with this approach, enabling unprecedented grid sizes. On a 4-way NV GraceHopper (GH200) node we accomodate 17 billion grid points, and similar on OLCF Frontier (AMD Trento--MI250X), enabling better than 100 trillion grid points simulations OLCF Frontier, LLNL El Capitan, and JSC JUPITER. Results show ideal weak scaling to full-system on US and European flagship computers.