Utilizing Wake Survey Methods to Evaluate Skin Friction Drag over a Rough Surface Cylinder*

Increasing the efficiency of modern aircraft is an important topic in reducing the environmental effect of air travel. Aircraft efficiency is largely dependent on the overall drag effect during flight. Skin friction drag increases over time as a result of the harsh conditions of atmospheric flight and inclement weather. As the smooth surface of an aircraft deteriorates, the surface roughness increases. These conditions cause early boundary layer separation and a corresponding increase in skin friction drag. This paper will seek to demonstrate the effect of surface roughness on the wake of a cylindrical body, thereby providing an estimation of the drag increase by comparing the wake of a smooth cylinder to a rough cylinder. The experiment will be conducted in the University of Texas at San Antonio’s low speed, 1.5’x1.5’ wind tunnel. A traverse mechanism will be employed over the cross-sectional area of the test section at increasing axial distances behind the bodies. In this way, the complete profile of the wake can be observed as it develops.

Using this method, the author will evaluate the wake profile and the effect of surface roughness on the skin friction drag of a fundamental aerodynamic shape under the greater context of aircraft efficiency.