Presenter/Author Information

Pelliccioni Armando, Inail ResearchFollow

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

Description

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.

 
Jun 17th, 2:00 PM Jun 17th, 3:20 PM

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.