TRUST is a thermalhydraulic software package for CFD simulations. This software was originally designed for conduction, incompressible single-phase, and Low Mach Number (LMN) flows with a robust Weakly-Compressible (WC) multi-species solver. However, a huge effort has been conducted recently, and now TRUST is able to simulate real compressible multi-phase flows. TRUST is also being progressively ported to support GPU acceleration (NVidia/AMD). TrioCFD is the Computational Fluid Dynamics (CFD) code based on the TRUST platform. The code contains Front_Tracking, Radiation, ALE for fluid/structure interactions and Turbulence LES & RANS models. Both softwares are OpenSource (BSD license).
Testimony from Pierre Ledac, CEA Engineer-Researcher, who has been maintening and developing TRUST:
[!QUOTE] “TRUST, the HPC platform for computational fluid dynamics on which several thermohydraulic applications are being developed, has incorporated the Kokkos middleware since 2024. Thanks to this middleware and a gradual rewrite of its algorithms (30% complete in early 2026), several numerical simulations using TRUST can now be run and accelerated on various GPU architectures (Nvidia, AMD). As a demonstrator for the CExA project from its inception, TRUST has benefited from significant support, both from the CEA team and the rapidly growing Kokkos community, through training and technical assistance. The most recent milestone for the CExA project is the optimization of a Kokkos feature (loop merging for nested parallelism), which was requested by the TRUST developers, successfully implemented by the CExA team, and integrated into the latest official version of Kokkos: as a result, the code saw a 30% speedup across several of its compute cores.”
Some TrioCFD calculations:
