A high-performance chemistry solver for reactive flow simulations in OpenFOAM

Reactive flow simulations with detailed chemical kinetics encounter significant computational challenges due to stiff, nonlinear combustion processes. This work presents a high-performance, central processing unit accelerated lightweight chemistry solver for OpenFOAM, an open-source software for computational fluid dynamics, that integrates code-level optimizations—including vectorized reaction rate evaluation, novel Jacobian construction for elementary reactions, and optimized matrix operations—with dynamic load balancing for multi-core scalability. In addition, the solver is fully compatible with the OpenFOAM ecosystem, requiring no external libraries or mechanism-specific code generation, thereby ensuring ease of integration and broad applicability to diverse chemical mechanisms. This solver is rigorously validated based on a hierarchy of test cases, including zero-dimensional autoignition, two-dimensional counterflow diffusion flames, and large eddy simulations of turbulent jet flames. Comprehensive benchmarks against the standard OpenFOAM chemistry solver demonstrate that the proposed solver can achieve up to an order-of-magnitude acceleration across a range of stiff ordinary differential equation algorithms, tolerance settings, and chemistry mechanisms from 10 species to 255 species, meanwhile maintaining solution fidelity. Cross-architecture robustness, superior computational efficiency compared with state-of-the-art solvers (e.g., DLBFoam), and good parallel scalability have also been validated for the proposed solver. This proposed solver presents the capability of significantly extending the practical feasibility of high-fidelity simulations with detailed chemistry.