Physical modeling of flow over an axisymmetric knoll under neutral atmospheric conditions [report]

W.C. Cliff, J.D. Smith
1980 unpublished
The Pacific Northwest Laboratory used a glass-walled hydraulic (water) flume to physically model air flow near an axisymmetric knoll in a neutral atmospheric boundary layer. The knoll was a 1:250 scale model. An upstream velocity profile (1/7 power law), characteristic of a neutral atmospheric boundary layer, was produced by locating a 10-cm-high (4-in.) trip near the flume entrance and by appropriately roughening the flume floor. Mean velocity, rms velocity, and turbulence intensity profiles
more » ... re measured at locations near the knoll using an existing laser Doppler anemometer system. The flow accelerated over the knoll and produced a relatively uniform velocity profile at the crest. The measured velocity profile was in close agreement with a theoretical velocity profile developed using potential flow theory and an upstream power law velocity profile. The turbulence intensity decreased at the crest of the knoll as a result of the flow acceleration. v " . ,
doi:10.2172/5569503 fatcat:ab4oia3pobfspf4halgwlbr47e