On the displacement height in the logarithmic velocity profile
- 1 October 1981
- journal article
- research article
- Published by Cambridge University Press (CUP) in Journal of Fluid Mechanics
- Vol. 111 (-1) , 15-25
- https://doi.org/10.1017/s0022112081002279
Abstract
The displacement height appears in the logarithmic velocity profile for rough-wall boundary layers as a reference height for the vertical co-ordinate. It is shown that this height should be regarded as the level at which the mean drag on the surface appears to act. The equations of motion then show that this also coincides with the average displacement thickness for the shear stress.A simple analytical model, experimental results and dimensional analysis are all used to indicate how the displacement height depends upon the detailed geometry of the roughness elements.Keywords
This publication has 12 references indexed in Scilit:
- An Investigation of the Forces on Three Dimensional Bluff Bodies in Rough Wall Turbulent Boundary LayersJournal of Fluids Engineering, 1977
- DETERMINATION OF SAND ROUGHNESS FOR FIXED BEDSJournal of Hydraulic Research, 1974
- A wind-profile index for canopy flowBoundary-Layer Meteorology, 1972
- Structural features of turbulent flow over smooth and rough boundariesJournal of Fluid Mechanics, 1971
- Momentum absorption by vegetationQuarterly Journal of the Royal Meteorological Society, 1971
- Wind tunnel determination of the roughness length as a function of the fetch and the roughness density of three-dimensional roughness elementsAtmospheric Environment (1967), 1971
- Turbulence Characteristics In Free Surface Flows Over Smooth And Rough BoundariesJournal of Hydraulic Research, 1971
- Rough wall turbulent boundary layersJournal of Fluid Mechanics, 1969
- Flow Phenomena Near Rough BoundariesJournal of Hydraulic Research, 1969
- On the Turbulent Structure of Airflow withinJournal of the Meteorological Society of Japan. Ser. II, 1963