Drag reduction over embedded cavities in Couette flow

作者：Lang A W^*; Johnson T J

来源：Mechanics Research Communications, 2010, 37(4): 432-435.

DOI：10.1016/j.mechrescom.2010.04.011

• Couette flow
• Drag reduction
• Cavity flow
• Low Reynolds number

Using a newly developed Couette flow facility with high viscosity oil as the working fluid, drag measurements over a patterned surface consisting of two-dimensional square embedded cavities orientated transversely to the main flow were experimentally obtained. Drag data was then compared to that obtained over a flat plate. Results show that for Re < 15 (where Re is based on the gap height) an appreciable drag reduction of >5% is obtained. This reduction, known as the "roller bearing effect", is due to the formation of embedded vortices within the cavities. Also, as the Re decreases the theoretical Stokes limit of 18% drag reduction is approached.

• 出版日期2010-6