High-Fidelity Simulation of the Aerothermal Performances of a Turbofan Thrust Reverser

Abstract Thrust reversers (TR) are one of the primary braking systems of aircrafts. They rely on a deflection of the airflow exiting the engine to generate a counter-thrust. Current steady-state numerical approaches used in the design phase, such as RANS (Reynolds-Averaged Navier-Stokes), fail to correctly predict the aerothermal performances of impinging configurations. This paper presents a methodology for the Large-Eddy Simulation (LES) of a representative reduced-scaled TARGET configuration. It relies on a two-step workflow to get the maximum accuracy at an optimal cost. First, a Low-Mach number variable density simulation is conducted. Despite not taking into account compressible effects, the accumulated statistics are used to perform feature-based mesh adaptation. A dedicated procedure based on the homogenization of the dissipation of the turbulent kinetic energy and on the boundary layer resolution allows to generate a grid with a controlled number of cells. The grid is refined in regions of prime interest for the study of this configuration, i.e. in the mixing layer and the impinging region, while it is coarsened in the far field. Then, the second step relies on the use of an explicit compressible solver to solve for the flow dynamics. Statistics are converged on this grid for later post-processing and comparison with experimental data.