• experimental evaluation
• BARC Benchmark
• angle of attack
• rectangular cylinder

The present thesis is aimed at investigating the effect of small angles of attack on the flow around a 5:1 rectangular cylinder. Experiments are carried out in the subsonic wind tunnel at DICI, University of Pisa. The angle of attack of the flow is varied between -2 and +2 degrees. The Reynolds number, based on the body transverse length and the freestream velocity is Re=40000.
Pressure distribution on the body surface is measured through differential pressure transducers, placed directly inside the wind tunnel model. The velocity field is measured by using hot-wire anemometry. The effect of the angle of attack on the pressure distribution and on the mean flow recirculation along the body lateral surface are investigated. The positions of the border of the shear layers detaching from the upstream corners are also investigated. Frequency analysis has allowed evaluating the frequencies of the Kelvin-Helmholtz instability and wake vortex shedding. A comparison with the results of experiments carried out at zero degrees is also performed.