The characteristics of a laboratory produced turbulent Ekman layer |
| |
| Authors: | G C Howroyd P R Slawson |
| |
| Institution: | 1. Dept. of Mechanical Engineering, University of Waterloo, Waterloo, Ontario, Canada
|
| |
| Abstract: | The characteristics of the atmospheric turbulent Ekman boundary layer have been qualitatively simulated in an annular rotating wind tunnel. Observed velocity spirals found to exist within the wind tunnel resembled qualitatively those found in the atmosphere in that a two-layer structure was evident, consisting of a log-linear portion topped by an outer spiral layer. The magnitude of the friction velocity u * obtained from the log-linear profile agreed with that measured directly, i.e., that obtained from the relation: u * = (u′w′)1/2. Also, the effects of surface roughness on the characteristics of the boundary layer agreed with expected results. In cases where the parametric behaviour predicted by theory departed from the observed behaviour, the probable cause was the inherent size limitations of the wind tunnel. The ability to maintain dynamic similarity is constrained by the limited radius of curvature of the wind tunnel. The vertical distribution of turbulent intensity in the wind tunnel was found to agree qualitatively with an observed atmospheric distribution. Also, a vertical distribution of eddy diffusivity was calculated from tunnel data and found to give qualitatively what one might expect in the atmosphere. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
