Publication Date:
2019-07-13
Description:
A new formulation of helicopter rotor thickness, noise for hover and forward flight, is discussed. The parameters required for this formulation are rotor motion, planform and airfoil thickness distribution. A computer program has been developed to calculate the pressure signature due to blade thickness for a helicopter in arbitrary motion. Comparison with high-speed helicopter tests shows good agreement with calculations when the observer is in or near the horizontal plane in which the rotor disc lies. Characteristics of thickness noise are illustrated by numerical examples indicating strongly that the high-speed blade slap may be due primarily to the thickness effect. The methods of Deming and Arnoldi are discussed as the special cases of this technique.
Keywords:
Aircraft Design, Testing and Performance
Type:
AIAA Paper 75-453
,
AIAA 2nd Aero-Acoustics Conference; Mar 24, 1975 - Mar 26, 1975; Hampton, VA; United States
Format:
application/pdf
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