Accession Number : AD0013026


Title :   Aerodynamic Noise and the Estimation of Noise in Aircraft


Corporate Author : AERONAUTICAL SYSTEMS DIV WRIGHT-PATTERSON AFB OH FLIGHT CONTROL LAB


Personal Author(s) : ROGERS, ORVILLE R ; COOK, ROBERT F


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/013026.pdf


Report Date : Dec 1952


Pagination or Media Count : 48


Abstract : Aircraft noise in the frequency range above 600 cps which produces the greatest interference with speech communication, can be controlled by practical amounts of sound insulation and can be estimated from the indicated airspeed in most jet propelled or multi-engine propeller driven aircraft. Since interference with speech communication is the most serious effect of aircraft noise, the methods contained in this report for estimation of the insulation required enable the aircraft designers to provide for necessary sound insulation in the earliest design stages. The principal source responsible for noise above 600 cps in the aforementioned aircraft types is the airflow over the fuselage and this noise is found to depend approximately upon the 2.75 power of the indicated air speed. Sound reduction afforded by the insulation is also found to be simply related to the surface density of the batting plus that of any non-porous septa included in the blanket.


Descriptors :   *AERODYNAMIC CHARACTERISTICS , *AIRCRAFT NOISE , *AIRCRAFT CABINS , SOUND , SPEECH RECOGNITION , NOISE REDUCTION


Subject Categories : Military Aircraft Operations
      Acoustics
      Human Factors Engineering & Man Machine System
      Voice Communications


Distribution Statement : APPROVED FOR PUBLIC RELEASE