E-EPSILON MODELING OF TURBULENT AIR-FLOW DOWNWIND OF A MODEL FOREST EDGE

A two-dimensional E - epsilon model, which included the effects of pla nt-atmosphere interaction, was used to simulate air flow downwind of f orest edges for the purpose of predicting the microclimate in forest o penings. A suitable set of wall functions was selected to consider the aerodynamic effects of the ground in the opening. The model with disc retization and parameter schemes was validated using a set of data fro m a wind-tunnel experiment. The simulated wind speed and turbulence ki netic energy closely agreed with the measured values. After validation , the model was used to predict eddy diffusivity in the lee of the for est edge. The modelled spatial distribution of the eddy diffusivity ag reed in general with that calculated using wind-tunnel measurements. T he usefulness and limitations of the E - epsilon model are discussed.