We introduce algorithmic advancements designed to expedite simulations in OpenFOAM using GPUs. These developments include the following. (a) The amgx4Foam library, which connects the open-source AmgX library from NVIDIA to OpenFOAM. Matrix generation, involving tasks such numerical integration and assembly, is performed on CPUs. Subsequently, the assembled matrix is processed on the CPU. This approach accelerates the computationally intensive linear solver phase of simulations on GPUs. (b) Enhancements to code performance in reactive flow simulations, by relocating the solution of finite-rate chemistry to GPUs, which serve as co-processors. We present code verification and validation along with performance metrics targeting two distinct application sets, namely, aerodynamics calculations and supersonic combustion with finite-rate chemistry.

This study presents the implementation and validation of C++ library modules within the OpenFOAM Technology for high-fidelity simulations of multi-regime combustion in aero-engines. The dynamic thickened flame combustion model for large eddy simulations is integrated with ordinary differential equation solvers to enable fast direct integration of finite-rate chemistry on graphics processing units. The reacting solvers are extended to incorporate a mixture-averaged formulation for viscosity and thermal conductivity. Additionally, diffusion models are generalized to multicomponent mixtures to account for individual species contributions, along with corrections that support non-unity Lewis numbers in the diffusion terms of the convection-diffusion equations for chemical species. The methodology is validated against experimental data from the hydrogen/air flame produced by the hydrogen low NOx burner. The numerical results demonstrate the robustness, accuracy, and computational efficiency of the proposed approach, paving the way for future investigations into the complex physics of aero-engine installations powered by sustainable aviation fuels.