Preliminary experimental study of disturbances in a laminar boundary-layer due to distributed surface roughness

Mean flow and disturbance measurements have been made on a flat plate model, one meter long in the CWRU low speed wind tunnel using hot-wire anemometry. Tests were conducted on a smooth plate and with two different grades of sandpaper covering; first with a sandpaper covering giving Re sub K values centered around 10 and then with a coarser sandpaper have Re sub K values of about 150. The mean flow measurements indicated Blasius profiles for the smooth plate and with the finer roughness. With the coarser roughness the profile was best approximated by a Blasius profile at the early stations but then progressed toward a turbulent profile.