22nd Congress of International Council of the Aeronautical Sciences, Harrogate, UK, 28 August - 1st September, 2000
Paper ICAS 2000-2.9.R2

EXPERIMENTAL INVESTIGATION OF FLOWFIELD OVER A MULTI-ELEMENT AEROFOIL AND COMPARISON WITH COMPUTATIONAL PREDICTION

H. H. BRUUN, S. R. MADDAH
University of Bradford, UK

Keywords: multi-element aerofoil, fhw, rsm

This paper presents results obtained from a combined experimental and computational study of the flowfield over a multi-element aerofoil with and without an advanced slat. Detailed measurement of the mean flow and turbulent quantities over a multi-element aerofoil model in a wind tunnel have been made using pressure, stationary and flying hot-wire (FHW) probes. The model configuration spans the test section and is made of three parts: 1) an advanced slat, 2) a NACA 4412 main aerofoil, 3) a NACA 4415 flap. The chord lengths of the elements were 38, 250 and 83 mm respectively. The results were obtained at a chord Reynolds number of 2.5×105 and a free Mach number of less than 0.1. The slat performance at different angles of attack, a, were investigated and compared with cases without the slat. Numerical predictions have been obtained by solving the time-averaged Navier-Stokes equations incorporating a Reynolds Stress Model (RSM) for the same configurations. This paper presents results for both experimental and numerical selected cases placing the multielement aerofoil at angles of attack of 15° and 20° with the advanced slat and 5° and 15° without employing the advanced slat. The computational results are compared with experimental data, which showed excellent agreement for low angle of attack and good agreement for other cases without separation, taking into account errors in both the experimental and numerical results. However, discrepancies were in particular observed in the complicated shear layers and high turbulent intensity regions due to limitations in the turbulence model and also inadequate grid resolution.

view full paper