Multi-Physics Simulations With OpenFOAM in the Re-Design of a Commercial Combustor

The numerical description of combustion provides a good understanding of the thermal boundary conditions of a combustor already in the early design phase. With an accurate simulation, the thermal load on the combustor wall as well as the turbine inlet profile can be estimated and potentially tailored to the structural requirements. At MTU Aero Engines AG, the authors set up a multi-physics solver in OpenFOAM to support the development process for combustors. This article shows the activities for a redesign of a commercial engine combustor and the successful numerical description of all related physical aspects. The comparison of combustor liner temperatures predicted via Conjugate Heat Transfer (CHT) with thermal paint results show excellent agreement. The numerical results allow the evaluation of different redesign options with respect to maximum liner temperatures and impact on turbine inlet temperature profiles. The application of a multi-physics solver to real engine combustor designs is limited to the availability of computational power and acceptable running time. The applicability of the presented approach to complex engine designs is not only shown by the successful simulation results. The choice of an open source code allows the usage of massive parallelization. A parallelization up to 1024 CPUs was tested to evaluate the potential of speeding up the simulations. The results are encouraging and show that complex meshes with ∼15 million cells can be simulated within acceptable calculation time.