Aerothermal Prediction of Multiple Hot Jets in Crossflow for Aircraft Applications

Even though many technical applications feature multiple jets in crossflow, little attention has been paid so far to their simultaneous numerical simulation as a system. A special challenge in this context is the simulation of exhausts of air systems on aircraft since they feature multiple hot jets in crossflow at high Reynolds numbers. As standard statistical turbulence models are not capable of correctly predicting thermal mixing between the jet and crossflow as well as interjet mixing, the scale-adaptive simulation is employed. In a first step, a simplified configuration comprising five laterally aligned jets is investigated, and numerical results are compared to wind tunnel data with good agreement. The establishing flowfield is analyzed, and its dynamics are compared to a single jet in the crossflow reference case. In a second step, the exhaust of an existing antiicing system is considered on an aircraft under realistic flight conditions. To take into account the local flow topology and to reduce computational costs, a sequential simulation methodology is applied, which relies on a Reynolds-Averaged Navier-Stokes simulation of the aircraft to provide boundary conditions for a subsequent scale-adaptive simulation calculation in a truncated subdomain. Results are compared to flight test data with good agreement, which highlights the applicability of the proposed approach.