機械通風式冷却塔からの白煙予測手法の開発 : 第2報,白煙予測のための数値シミュレーション(流体工学,流体機械)  [in Japanese] Development of Prediction Method for a Visible Plume from a Mechanical Draft-Cooling Tower : 2nd Report, Numerical Simulation to Predict a Visible Plume(Fluids Engineering)  [in Japanese]

A Large-eddy simulation (LES) was developed to predict a visible plume region from a mechanical-draft cooling tower. This numerical model solves the equations for conservation of mass, momentum, energy, vapor and liquid water. It is assumed that the visible plume is generated whenever the instantaneous liquid water mixing ratio is existed. To estimate the accuracy of the present numerical model, the predictions of visible plume length and height are compared with observations. The results show the visible plume length and height are in good agreement with the observations. Furthermore, we investigate the basic behavior of the visible plume and temperature emitted from the cooling tower under severe metrological condition. It is found that whether the visible plume reaches the ground or not mostly depends on the wind angle to the cooling tower, and temperature emitted from the cooling tower has little influence on atmosphere environment on the ground.