An Undergraduate Research Project: Experimental Investigation Of Drag Reduction For A Cylinder With An Attached Fin

An example of an undergraduate research project carried out in the area of fluid mechanics is reported in this paper. This project can also be used as a laboratory demonstration, and can easily be reproduced in departments elsewhere. Specifically, an experimental investigation was conducted to determine how drag is affected when a longitudinal fin is attached to the trailing edge of a cylinder. Models were mounted normal to the flow direction in an open loop wind tunnel. A strain gage-based load cell was designed, fabricated and calibrated to measure the drag, and it was mounted outside the test section just beneath the wind tunnel floor. The experimental variables included the air speed and fin length, creating a range of Reynolds number from 22 x 103 to 105 and fin length to cylinder radius ratio of 0.25 to 2. Tests with cylinder without fin were also performed to obtain base-line data for comparison. Results indicate that the addition of fin causes a reduction in drag compared to a cylinder without a fin. Future research direction is outlined.