Visualization analysis of the starting flow around a pitching airfoil (2nd report, NACA 0012 airfoil with a variable pitching axis)

• Published in: Nihon Kikai Gakkai rombunshuu. B hen Vol. 55; no. 519; pp. 3403 - 3412
• Main Authors: Ohmi, K, Coutanceau, M, Loc, T P, Dulieu, A
• Format: Journal Article
• Language: Japanese
• Published: 01.01.1989
• Subjects: airfoils; oscillation
• ISSN: 0387-5016
• DOI: 10.1299/kikaib.55.3403

The starting flows past a two-dimensional NACA 0012 airfoil pitching at large incidences are examined by visualization experiments and numerical calculations. The principal parameters are the Reynolds number ranging between 1,500 and 10,000, the reduced pitching frequency between 0.1 and 1.0, and two angular variables corresponding to the mean incidence and the amplitude of the oscillation. The instantaneous incidence of the airfoil is often in excess of the static stall angle and can be as large as 45 degree . The effects of these parameters on the wake formation are discussed in some detail, and in this report, there is special interest in the effect of the airfoil cross section and that of the pitching axis.