Solvers

Our group maintains these in-house CFD solvers:

1. ExaFlow
   • An exascale-capable in-house flow solver
     • original version developed by Dr. Jain
     • currently developed and maintained by FPCS group members (Luis, Anirban, and others)
     • written in C++
   • Capabilities:
     • single-phase and two-phase flows
     • incompressible and compressible flows
     • direct numerical simulation and large-eddy simulation of turbulent flows
     • multiphysics phenomena, such as, scalar transport, surfactant transport, electrostatics, electrokinetics, fluid-solid interactions, elastic-plastic deformation in solids
     • non-Newtonian fluids (under development)
     • reacting flows (under development)
     • handles complex geometries (under development)
   • Numerical methods:
     • low-dissipation numerics
     • kinetic energy–and entropy-preserving schemes
   • Scalability:
     • Scales well to over 200K CPU cores on Mira & Theta supercomputers (now decommissioned)
     • Scales well to over O(10K) GPUs on Frontier supercomputer.
2. charLES-M
   • An in-house Voronoi grid-based unstructured grid multiphase solver capable of large-scale simulations of flow over complex geometries.
   • This is developed on top of the charLES framework (by Cascade Technologies).
   • The current in-house version of the code employs low-dissipation numerics to simulate:
     • particle-laden flows on GPUs (tested on Lassen and Summit supercomputers).
     • incompressible two-phase flows on CPUs (tested on quartz supercomputer).

Currently, these two solvers are not open-source.

For more codes, see Suhas’s Github page or the FPCS Lab Github page.

We also use and modify open-source codes like Basilisk and OpenFOAM.