カルマン渦が干渉する場合の翼騒音特性

抄録

Recently, it has been a problem of aerodynamic noise radiated from airfoils. Therefore, the authors made wind tunnel tests to measure airfoil noise and static pressure on an airfoil (NACA0012 model, chord length: 150 mm, span length: 500 mm, wind velocity: 30 m/s, angle of attack: 9 degrees, Reynolds number: 3.0×10⁵ ) in turbulent flow. In this study, the authors use the airfoil and a cylinder to examine influences of vortices with a particular size and fluctuation. Then, the authors measure airfoil noise and static pressure in varying position in the vertical direction (-60 to +40 mm) and diameter (6 to 10 mm) of the cylinder placed in the upstream side of the airfoil to change interference position and size of the vortices and airfoil. As a result, it has become clear that airfoil nose is increased when interference position is in the stagnation point. And the airfoil has larger pressure fluctuation at leading edge in this case.