Test and Verification of Vortex Shedding for a 3D bluff body

Testing of a 3D bluff body with and without end plate tabs was performed in the California Polytechnic State University 3x4 ft low speed wind tunnel. The CP values were obtained for the test case with no end plate tabs for speeds of 10, 15, 20, and 30 m/s. It was observed that stronger vortex shedding ocured at the higher speed test cases. The model was shimmed to be at approximately 5° angle of attack in order to obtain symmetrical negative CP spikes for the top and bottom of the model without tabs. Trends were observed and compared to trends previously noted in Jarred Pinn’s thesis. The baseplate was replaced with one that contained tabs along the spanwise direction, and it was observed that the vortex shedding was eliminated with the addition of the base plate tabs. The data obtained confirmed previous trends seen that tabs resulted in reduced drag and elimination of vortex shedding at the top and bottom of the model base.