Experimental Investigation of Acoustic Excitation on NACA 0012 Airfoil Wake Development

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Hasani, Maedeh | 2015

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Type of Document: M.Sc. Thesis
Language: Farsi
Document No: 47258 (45)
University: Sharif University of Technology
Department: Aerospace Engineering
Advisor(s): Soltani, Mohammad Reza; Masdari, Mehran
Abstract:
Acoustic excitation frequency effect on NACA 0012 airfoil boundary layer and on its wake development was investigated experimentally in two wind tunnels. Airfoils chord lentgh were 100 and 152 mm. Flow Reynolds numbers was 60000 and 160000 in the first wind tunnel and 100000 and 250000 in the second one. Excitation frequency range was chosen between 300 and 2400 Hz. Airfoil flow and sound characteristics was measured using a 1-D hot-wire sensor and two microphones, one mounted on the wind tunnel wall and the other flash mounted on the model at 10 percent of chord length, respectively. Airfoil angle of attack was set at zero degree in the first wind tunnel and at three angles of zero, five and ten degrees in the second wind tunnel. As a consequence, for certain frequencies, acoustic pressure rise accoured and boundary layer turbulence intensity was amplified and finally the drag was reduced. Note the airfoil angle of attack and Reynolds number affected on it too
Keywords:
Acoustic Excitation ; Boundary Layer ; Airfoil ; Wind Tunnel ; Microphone ; Wakes ; Hot-Wire Sensor

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