Transonic Rotor Noise Theoretical And Experimental Comparisons

Download or read book Transonic Rotor Noise written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-06 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two complementary methods of describing the high speed rotor noise problem are discussed. The first method uses the second order transonic potential equation to define and characterize the nature of the aerodynamic and acoustic fields and to explain the appearance of radiating shock waves. The second employs the Ffowcs Williams and Hawkings equation to successfully calculate the acoustic far field. Good agreement between theoretical and experimental waveforms is shown for transonic hover tip Mach numbers from 0.8 to 0.9. Schmitz, F. H. and Yu, Y. H. Ames Research Center NASA-TM-81236, A-8342, AVRADCOM-TR-80-A-12 RTOP 992-21-01-90-01