Experimental analysis of the aerodynamic characteristics of a rectangular 5:1 cylinder using POD

Following the BARC initiative, wind tunnel measurements have been performed on a 5:1 rectangular cylinder. Pressure distribution has been measured in several sections, checking the two-dimensionality of the flow around the model. Mean values compare well with previous data. These measurements have been processed using the standard Proper Orthogonal Decomposition (POD) and the snapshot POD to obtain phase-resolved cycles. This decomposition has been used to analyze the characteristics of the flow around the cylinder, in particular, the behavior of the recirculation bubble in the upper/lower surfaces. The effect of the angle of attack, the turbulence intensity and the Reynolds number has been studied. First and second modes extracted from POD have been found to be related to the reattachment of the flow in the upper surface. Increasing the angle of attack is related to a delay in the reattachment position, while an increase in turbulence intensity makes the reattachment point to move towards the windward face.

Automated summary

This study conducted wind tunnel measurements on a 5:1 rectangular cylinder to analyze the flow characteristics. The pressure distribution was measured in several sections to validate the flow's two-dimensionality. The Proper Orthogonal Decomposition (POD) was used to process the measurements and obtain phase-resolved cycles. The study focused on the behavior of the recirculation bubble and investigated the effects of angle of attack, turbulence intensity, and Reynolds number.