Modeling Approach and Departure Noise of the Joby Aviation Aircraft

A computational method for modeling approach and departure noise of electric vertical takeoff and landing (eVTOL) aircraft is validated using flight test measurements of the Joby Aviation aircraft. The methodology consists of performing high-fidelity computational fluid dynamics simulations to generate acoustic hemispheres that are used as input in a noise propagation software package. Three hemispheres were generated based on waypoints in an approach trajectory. A simulation of hover was conducted to generate a hover hemisphere. The effects of hemisphere resolution, terrain, and airframe acoustic shielding were explored. Overall, there is an overprediction of noise but the comparison with measured values improves as the model becomes more complete, indicating that the method is capturing the physics correctly. The same set of hemispheres was applied to a different approach trajectory and demonstrated similar results with reasonable agreement to measurements. However, application of the approach hemispheres to a departure trajectory resulted in a larger overprediction of noise due to the differences in the trim conditions.