Numerical simulations of the mean wind speeds and turbulence intensities over simplified gorges using the SST <i>k</i>-<i>ω</i> turbulence model

Abstract

Numerical studies on the wind characteristics over gorge and valley terrains are very rare. Some simplified gorge terrains with different included angles and different terrain heights were adopted in the present study in order to obtain the basic information about the wind characteristics. To ensure the accuracy of the numerical results before conducting the actual numerical simulations, a new form of turbulence kinetic energy profile to serve as an inlet boundary condition was proposed based on the SST k-ω turbulence model. Then, the wind characteristics – including the mean wind speeds, turbulence intensities and mean square deviations – of the turbulent flow in the gorge terrain were studied for different included angles and different terrain heights. The results showed that the larger the included angle of the gorge terrain, the more significantly the mean wind speeds at the gorge center increase. The mean square deviation values of the turbulent flow at the gorge center are much smaller than those at the inlet. The effects of the terrain height on wind characteristics such as the mean wind speed and turbulence intensity at the gorge center are very small. The research conclusions can provide a point of reference for the wind characteristics over real gorge terrain and the simulation method of the current study can provide a new idea for other numerical simulations.