Implementation and verification of an OpenFOAM solver for gas-droplet two-phase detonation combustion

Due to the complexity and short timescale of detonation, it is usually difficult to capture its transient characteristics experimentally. Advanced numerical methods are essential for enhancing the understanding of the flow field structure and combustion mechanism of detonation. In this study, a density-based compressible reactive flow solver called CDSFoam is developed for simulating gas-droplet two-phase detonation combustion based on OpenFOAM. The primary feature of this solver is its implementation of two-way coupling between gas and liquid phases, utilizing the Eulerian–Lagrangian method. The key enhancement is an improved approximate Riemann solver used to solve the convective flux, reducing dissipation while ensuring robustness. Time integration is achieved through the third-order strong stability preserving Runge–Kutta method. Additionally, CDSFoam incorporates dynamic load balancing and adaptive mesh refinement techniques to mitigate computational costs while achieving high-resolution flow fields dynamically. To validate the reliability and accuracy of the solver, a series of benchmark cases are examined, including the multi-component inert and reactive shock tube, the stable diffusion process, the Riemann problem, the one-dimensional detonation, the two-dimensional detonation and oblique detonation, the droplet phase model, the two-dimensional gas–liquid two-phase detonation, and the two-phase rotating detonation. The results show that CDSFoam can well predict the shock wave discontinuity, shock wave induced ignition, molecular diffusion, detonation key parameters, detonation cell size, and the main characteristics of gas–liquid two-phase detonation.