OS9-10 翼周りの流れと騒音の受動的制御による揚力・抗力への影響(OS9 熱流動,循環型社会における動力エネルギー技術)

Abstract

In this paper we attempted to reduce the aerodynamic noise generated from a two-dimensional NACA0012 airfoil at a Reynolds number of 3×10^5 in post-stall condition by passive flow and noise control on airfoil surface with various materials. The experimental results showed that the Pile Fabrics reduced the aerodynamic noise with 4.4dB in post-stall condition, but in spite of the remarkably thin pile fabrics degraded lift and drag performance of the airfoil. In case of the control by relatively thin Urethane, even if airfoil surface was largely covered, there had no reduction of aerodynamic noise but little degradation of lift and drag performance. In case of the control by Net, there had least degradation of lift and drag performance among the materials and a little reduction of aerodynamic noise in post-stall condition about 1.8dB.