Friction measurement in zero and adverse pressure gradientboundary layer using oil droplet interferometric method

摘要

The oil droplet interferometric technique hasbeen used to investigate the skin friction distribution alonga zero and adverse pressure gradient boundary layerdeveloping in the Laboratoire de Mecanique de Lille windtunnel. This experimental task was a part of the WALL-TURB project, funded by the European Community, inorder to bring significant progress in the understanding ofnear wall turbulence in boundary layers. Skin frictionvalues close to 0.01 Pa have been measured with thisoptical method. A comparison with the results obtainedwith hot-wire anemometry and macro-PIV demonstratesthe great potential of the oil droplet technique.