A Turbulent Flow Model for Use in Numerical Evaluation of Air Quality

Abstract

Several articles have appeared recently which describe air quality models combining a wind flow calcula,tion with the calculation of pollutant dispersion. Most of them use simplified methods to obtain the wind field. In the present study, one of these methods (termed a modified potential method) is compared with a turbulent flow model based on the solution of the Navier-Stokes equations. A simple model of turbulence, suitable for environmental applications, is developed. The comparative results show that the modified potential model is adequate for many large-scale environmental studies. Its applicability is limited where local effects associated with viscous flow a,re extremely important. Such cases can be nWl'e realistically sitnulated with the tttt'-bulent flow model, although at significantly higher costs.

Sites for wind power installations: wind tunnel simulation of the influence of two-dimensional ridges on wind speed and turbulence. Annual report, first year

“…These models are generally dependent on real time specification of synoptic wind fields or interpolation between real time data gathered at a number of field sites simultaneously. Three-dimensional mass consistent wind field models have been prepared by Seltari and Lantz (1974), Dickerson and Orphan (1975), Sherman (1975), Freeman (1976), and Knox, et ale (1976). Integration of the continuity equation in the vertical direction results in a shallow layer version which requires only a twodimensional so1ution for an average duration from the mean wind.…”