Accession Number : ADA260703


Title :   Far Field Rotor Noise


Descriptive Note : Final rept.


Corporate Author : ARIZONA STATE UNIV TEMPE DEPT OF MECHANICAL AND AEROSPACE ENGINEERING


Personal Author(s) : Wells, Valana L


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a260703.pdf


Report Date : 22 Jan 1993


Pagination or Media Count : 27


Abstract : The work covered two main areas of research--the aerodynamics of rotor blades including viscous and high angle of attack effects and, secondly, the propagation of noise from the rotor blade, particularly the nonlinear propagation. The aerodynamics work included the development and testing of a Navier-Stokes computational solver for rotor blades which incorporates rotating, translating, flapping and feathering motions. Results, which focus on the British Experimental Rotor Programme (BERP) blade, clearly show the importance of including all motions in the calculation of aerodynamic-forces. The acoustics research concentrates on the development of a method for computing the non linear propagation of acoustic signals in the atmosphere. The method is based on a boundary-element discretization of the time-dependent, nonlinear wave equation. Results, computed for a spherically symmetric domain, show an equivalence with Whitham's method up to the formation of a shock.


Descriptors :   *ANGLE OF ATTACK , *ROTOR BLADES(ROTARY WINGS) , *FAR FIELD , *AERODYNAMIC FORCES , *NOISE POLLUTION , *NONLINEAR PROPAGATION ANALYSIS , *HIGH ANGLES , *NONLINEAR ALGEBRAIC EQUATIONS , *ACOUSTIC SIGNALS , PROPAGATION , BOUNDARIES , WAVE EQUATIONS , AERODYNAMICS , ATMOSPHERES , ACOUSTICS , SIGNALS , SHOCK , HELICOPTERS , TIME , ARMY RESEARCH , MOTION


Subject Categories : Aerodynamics
      Astronomy
      Acoustics
      Noise Pollution and Control


Distribution Statement : APPROVED FOR PUBLIC RELEASE