Experimental study of interference drag for multi-element objects

The dynamic force in the direction of the upstream velocity developed on a blunt-body confined in a fluid stream is known as the drag. It has been observed that for multi-element objects the resultant drag can be greater than the sum of the drag forces of each of its elements depending on the geometry at the joints. The flow pattern there is a complex boundary layer that is generated by the mixing of the individual boundary layers over each of the elements. The ensuing diversion of the streamlines from their normal paths over the contour of these elements and the mixing of the boundary layers result in additional resistance, which is known as interference drag. This paper describes the results of an experimental investigation of interference drag for three simple two-element prismatic shapes, the L, the T, and the skewed T whose parts are joined at angles of 30degrees, 45degrees, 60degrees, and 75degrees. (C) 2002 Elsevier Science Inc. All rights reserved.