GPU-Accelerated Large-Eddy Simulations for Aeroacoustic Predictions of a Full-Wheel Multi-Stage Turbofan Engine

GPU-accelerated wall-modeled large-eddy simulations are performed for the full-scale HondaJet turbofan engine HF118-2. The configuration includes the non-axisymmetric nacelle and the full-wheel fan, low-pressure compressor & low-pressure turbine stages. The bypass duct, outlet guide vanes, exhaust lobe mixer and all other main internal parts are also included, with the exception of the high-pressure compressor, combustor and high-pressure turbine components. Aerodynamics performance predictions are compared to cycle analysis estimates and show good agreement for the mass flow rates and bypass ratio, as well as the total pressure and temperature ratio for the different stages. Far-field noise is also predicted for comparison against microphone measurements for the isolated functioning engine operating at take-off conditions. The jet noise and fan noise components are well captured in terms of both broadband and tonal levels, as well as sound directivity, with the exception of the upstream angles where the tonal fan noise is under-predicted. An additional simulation is performed where the nacelle exterior is replaced by an extended axisymmetric bellmouth intake matching the geometry used in the experiment. With the bellmouth, the aerodynamic performance and jet noise remain unchanged but the upstream fan noise radiation is modified, resulting in a better agreement with measurements.