Accelerated numerical simulations of hydrogen flames : Open-source implementation of an advanced diffusion model library in OpenFOAM

Here, the OpenFOAM software with the dynamic load balancer library DLBFoam is investigated for computational fluid dynamics (CFD) simulations of different hydrogen (H₂) flames. The benefits of DLBFoam for hydrogen have not been thoroughly investigated in the past. To explore this, a new open-source diffusion model library FickianTransportFoam is implemented in this study. FickianTransportFoam includes species-specific constant Lewis number and mixture-averaged models with correction velocity to account for preferential diffusion. The model is first verified for one-dimensional (1D) premixed and non-premixed counterflow flames. Additionally, four hydrogen/air flames are explored: (1) two-dimensional (2D) laminar freely propagating premixed flame, (2) 2D axisymmetric laminar non-premixed jet flame, (3) three-dimensional (3D) turbulent non-premixed swirling flame, and (4) 3D turbulent premixed swirling flame. The main results and achievements regarding the implemented transport models are as follows. First, the results from 2D freely propagating flame demonstrated thermodiffusively unstable flame formation using the mixture averaged model. The analytical and numerical dispersion relationships agree well for the linear instability growth phase. Second, the model functionality is demonstrated for a laminar 2D jet case with conjugate heat transfer. Furthermore, validation and grid sensitivity studies for the 3D turbulent flames are carried out. Third, the computational benchmark for each configuration indicates a factor of ∼10-100 speed-up when utilizing DLBFoam. Finally, the test cases and source codes for FickianTransportFoam are openly shared.