A validation study of the PSU-WOPWOP rotor noise prediction system

Recently a new rotor noise prediction code, PSU-WOPWOP, has been developed to predict the rotor noise for maneuvering rotorcraft. The code has been used for a wide variety of maneuvers - especially focusing on transient maneuver noise. Although the theoretical basis of the code is Farassat's Formulation 1A - the same as the NASA WOPWOP code that has been extensively validated - PSU-WOPWOP is a completely new code and needs validation to ensure that the predictions are reliable. The main problem is that virtually no experimental data is publically available for maneuvering flight conditions. This study aims to validate the PSU-WOPWOP rotor noise prediction code in combination with the Maryland Free-Vortex Wake (MFW) model used in the previous maneuver studies for steady flight conditions in which experimental data does exist. This rotor noise prediction system will be validated against several experiments including a contemporary design, four-bladed rotor, the Higher Harmonic Aeroacoustic Rotor Test (HART I), and a XV-15 flyover flight test. Through this study a better understanding of the accuracy and fidelity of the results predicted for maneuvering flight conditions can be gained, allowing for better evaluation of future uses and highlighting areas that will benefit from future work.