Keywords
Von Karman, near-neutral, neutral, Reynolds, Roughness length
Location
Session H6: Environmental Fluid Mechanics - Theoretical, Modeling and Experimental Approaches
Start Date
17-6-2014 2:00 PM
End Date
17-6-2014 3:20 PM
Abstract
The Von Karman constant k is important for the study of lower layer of atmosphere. This parameter can be calculated using two methods: the gradient methods and the profile methods. In this work the profile methods has been applied. A dataset, collected in a meteorological tower sited at the National Wind Technology Center in Boulder was used. Data were selected for high neutral turbulence conditions, vertical homogeneity for the wind direction and friction velocity. A near-neutral correction has been applied to the observed Von Karman constant. The profile method permits to calculate the roughness Reynolds number, a parameter link to viscosity and rough scale. The results show the existence of correlations between k and Re*. In particular the classic values of k=0.40 is related to high value of Re*, while low values may be associated with low values of the Reynolds number.
Included in
Civil Engineering Commons, Data Storage Systems Commons, Environmental Engineering Commons, Hydraulic Engineering Commons, Other Civil and Environmental Engineering Commons
Relationship between Von Karman and Reynolds number: a critical analysis using the wind profile method
Session H6: Environmental Fluid Mechanics - Theoretical, Modeling and Experimental Approaches
The Von Karman constant k is important for the study of lower layer of atmosphere. This parameter can be calculated using two methods: the gradient methods and the profile methods. In this work the profile methods has been applied. A dataset, collected in a meteorological tower sited at the National Wind Technology Center in Boulder was used. Data were selected for high neutral turbulence conditions, vertical homogeneity for the wind direction and friction velocity. A near-neutral correction has been applied to the observed Von Karman constant. The profile method permits to calculate the roughness Reynolds number, a parameter link to viscosity and rough scale. The results show the existence of correlations between k and Re*. In particular the classic values of k=0.40 is related to high value of Re*, while low values may be associated with low values of the Reynolds number.
