106 REDUCTION OF FLOW GENERATED NOISE OF AIRFOILS BY MEANS OF ACOUSTICALLY SOFT COATING(O.S.2 Vibration and Noise Reduction Technology II)

概要

論文の詳細を見る
Comparative acoustic and wind tunnel experiments were carried out on uncoated and coated isolated airfoils. The aim of the tests was to survey the airfoil noise reducing effect and the aerodynamic impact of the acoustically soft coating consisting of filaments, as a preliminary study in application of such coatings to axial flow turbomachinery bladings. It was found in the acoustic tests that the coating successfully reduces the sound pressure in the frequency range critical from the aspect of human audition. The wind tunnel experiments included laser Doppler anemometer (LDA) studies on the development of the boundary layers (BL) and on the wake structure, and static pressure measurements on the blade surface and in the wake. The coating reduced the lift and increased the drag. A proposal has been made for further studies in order to retain the advantageous acoustic effects of the coating while avoiding the undesirable aerodynamic impact.
一般社団法人日本機械学会の論文
2005-05-31