Prediction of Acoustic Loads on a Launch Vehicle Fairing During Liftoff

摘要: A = coefficient matrix a cylinder radius, m b frequency band number C diagonal Q solid angle, rad c speed of sound in the exhaust flow, m=s De nozzle exit diameter, d projected distance, E total surface elements Ei element shape function F thrust rocket engine, N f frequency, Hz fb bandwidth, G Green’s H Hm z Hankel or Bessel third kind mth order and argument, IN identity Jm first k wave LP;b; pressure level on circumference vehicle, dB LP;OA; overall level, Lw acoustic power Lw;b for each band, M terms Me Mach term n nozzles, particle outward velocity direction P field point observation p, p pressure, Pa incident pi constant nodal ith element, amplitude, scattered pa at cylinder, p0 spatially dependent factor projection point, integration boundary Qs source strength, =s R distance between resultant oblique r radial from exit, rP rQ S area, Ue velocity, un normal V volume problem geometry, Ve exterior volume, 3 Vi interior Wb Watt W per Hz, WOA power, X component cylindrical coordinate axes x1 axial vehicle x2 vertical sources along flow axis, x3 axis Y Z elevation height, incline angle line joining to location deg phase "m used equations horizontal noise radiation, wavelength, density air kg=m Received 25 January 2012; revision received 6 May accepted publication 9 2012. Copyright © 2012 by Mir Md. Maruf Morshed, Colin H. Hansen, Anthony C. Zander. Published American Institute Aeronautics Astronautics, Inc., with permission. Copies this paper may be made personal internal use, condition that copier pay $10.00 per-copy fee Clearance Center, 222 Rosewood Drive, Danvers, MA 01923; include code 0022-4650/13 correspondence CCC. ∗Assistant Professor, Department Mechanical Chemical Engineering. School Associate JOURNAL OF SPACECRAFT AND ROCKETS Vol. 50, No. 1, January–February 2013