Experimental Study of Free Stream Turbulent Effects on Dynamic Stall of Pitching Airfoil by Using Particle Image Velocimetry

Autor: Shih-Jiun Chen, Jui Ming Yu, J. Y. Li, C. C. Hu, J. C. Cheng, Jiun-Jih Miau, Tzong-Shyng Leu, S. Y. Liang
Rok vydání: 2012
Předmět:
Zdroj: Applied Mechanics and Materials. 225:103-108
ISSN: 1662-7482
DOI: 10.4028/www.scientific.net/amm.225.103
Popis: The unsteady flow fields above NACA 0015 airfoil pitching with/without upstream turbulence generator are investigated in a water tunnel by mean of particle image velocimetry (PIV). The turbulence was generated by a square bar mesh situated at the inlet of the test section. The airfoil pitching waveform is performed under the condition calculated from the angle of attack histogram of a vertical axis wind turbine (VAWT). By using PIV, the instantaneous vortex structures above the pitching airfoil can be revealed. It allows us to study the free stream turbulence effects on dynamic stall over an airfoil at pitching waveform the same as VAWT. It is found that the free stream turbulence intensity has significant impacts on the dynamic stall process. The dynamic stall process is delayed to higher incidence angles on increasing the turbulence intensity.
Databáze: OpenAIRE