Effect Of Wake Structure On Blade Vortex Interaction Phenomena Acoustic Prediction And Validation

Download or read book Effect of Wake Structure on Blade-Vortex Interaction Phenomena: Acoustic Prediction and Validation written by and published by . This book was released on 1995 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the Higher Harmonic Control Aeroacoustic Rotor Test, extensive measurements of the rotor aerodynamics, the far-field acoustics, the wake geometry and the blade motion for powered, descent, flight conditions were made. These measurements have been used to validate and improve the prediction of blade-vortex interaction (BVI) noise. The improvements made to the BVI modeling after the evaluation of the test data are discussed. The effects of these improvements on the acoustic-pressure predictions are shown. These improvements include re-structuring the wake, modifying the core size, incorporating the measured blade motion into the calculations and attempting to improve the dynamic blade response. A comparison of four different implementations of the Ffowcs Williams and Hawkings equation is presented. A common set of aerodynamic input has been used for this comparison. (AN).