Wake Turbulence Structure Downstream of a Cambered Airfoil in Transonic Flow: Effects of Surface Roughness and Freestream Turbulence Intensity. (2006)

• Record Type: Journal Article
• Authors: Zhang, Qiang; Ligrani, Phillip M.
• Is Part Of: International journal of rotating machinery. Volume 2006(2006)
• Publication Date: 2006
• Subjects: Machinery -- Periodicals; Rotary combustion engines -- Periodicals; Turbines -- Periodicals; Hydraulic machinery -- Periodicals; 621.82
• DOI: 10.1155/IJRM/2006/60234
• Languages: English
• ISSNs: 1023-621X

Abstract

Abstract : The wake turbulence structure of a cambered airfoil is studied experimentally, including the effects of surface roughness, at different freestream turbulence levels in a transonic flow. As the level of surface roughness increases, all wake profile quantities broaden significantly and nondimensional vortex shedding frequencies decrease. Freestream turbulence has little effect on the wake velocity profiles, turbulence structure, and vortex shedding frequency, especially downstream of airfoils with rough surfaces. Compared with data from a symmetric airfoil, wake profiles produced by the cambered airfoils also have significant dependence on surface roughness, but are less sensitive to variations of freestream turbulence intensity. The cambered airfoil also produces larger streamwise velocity deficits, and broader wakes compared to the symmetric airfoil.