The Effect of Small-Scale Roughness on the Mean Flow Profile of a Laminar Boundary Layer
The processes by which distributed surface roughness accelerate boundary layer transition remain unclear. Experimental studies aimed at clarification were carried out during the early 1980s by three groups who maintained intercommunication. In each case, Blasius-like boundary layers were selected for study for reasons of simplicity and standardization. The experiments by Leventhal  and by Corke, Bar-Sever, and Morkovin  concerned measurement of the growth of naturally-occurring flow fluctuations within laminar layers during passage over sandpaper roughness. In contrast, this author  chose to measure only the mean velocity alteration due to roughness, with the expectation that the distorted profile could be analyzed for incremental growth using stability theory.
KeywordsLaminar Boundary Layer Vortex Pair Boundary Layer Transition Distorted Profile Roughness Density
Unable to display preview. Download preview PDF.
- Leventhal, L., “Preliminary Experimental Study of Disturbances in a Laminar Boundary Layer Due to Distributed Surface Roughness,” M.S. Thesis, Case Western Reserve University, Cleveland, OH, December 1980.Google Scholar
- Kendall, J. M., “Laminar Boundary Layer Velocity Distortion by Surface Roughness: Effect upon Stability,” AIAA Paper 81–0195, St. Louis, January, 1981.Google Scholar