Investigation of slat heel effect on the flow field over multi-element airfoils

• Published in: Experimental thermal and fluid science Vol. 25; no. 8; pp. 651 - 658
• Main Authors: Maddah, S R, Gough, T, Pierscionek, B, Bruun, H H
• Format: Journal Article
• Language: English
• Published: 01.02.2002
• ISSN: 0894-1777

This paper presents results obtained from an experimental study of the flow field over a multi-element airfoil which incorporates either a conventional or an advanced slat. Detailed measurements of the mean flow and turbulent quantities over a multielement airfoil model equipped with either type of slat have been made in a wind tunnel using stationary and flying hot-wire (FHW) probes. The performance of the two slats at two angles of attack, 10 and 20 deg, was investigated and compared. The results showed a better performance for the advanced slat in terms of the mean velocity field and hence an increase in the lift performance. The advantage of the advanced slat was more pronounced for the multi-element airfoil placed at the higher angle of attack, i.e., 20 deg. These findings were substantiated by the Reynolds stresses measured over the multi-element airfoil with the conventional slat exhibiting higher values compared with its advanced slat counterpart. Both the mean velocity and Reynolds stress results clearly demonstrated that the conventional slat had a lower stall margin than the advanced slat. (Author)