Large Eddy Simulation Study on the Wind Characteristics of a Steep Escarpment

This work aims to study the influencing factors and spatial distribution characteristics of wind parameters in typical steep escarpment terrain. The narrowband synthetic random flow generation (NSRFG) method is employed to set target turbulent wind parameters, and large eddy simulations (LES) are performed on terrain models of varying scales. The relationship among the fluctuating wind spectrum function, turbulent kinetic energy resolution ratio, and grid size is established. The combined correction method using power and linear functions can quickly achieve the target wind profile. To reduce the output time of numerical simulation results, a Python program is developed to extract and reconstruct transient data in a user-defined subdomain of the computational domain. The results indicate that the wind parameters of the steep escarpment exhibit significant spatial variations and are significantly influenced by the direction of incoming flow and local terrain. The terrain scale impacts the results of wind parameters in numerical simulations. However, the overall characteristics of the numerical simulation results for the central region of terrain models at different scales are consistent. Regardless of the incoming wind direction, the maximum wind speed is always observed at the mountaintop. The turbulence intensity and wind attack angle at the junction of the escarpment are greater than those in homogeneous areas. The fluid vortices are compressed on the windward side of high mountains and generate rotating vortices at steep escarpments on the leeward side.