Gaoyuan qixiang (Apr 2024)
Application of Large Eddy Simulation on Qinghai-Xizang Plateau Wind for Airdrop
Abstract
The Qinghai-Xizang Plateau has complex terrain and climate, which is a great challenge to the airdrop parachute landing and aviation safety.This research focuses on Qinghai-Xizang Plateau wind field simulation in boundary layer based on numerical calculation method.Firstly, the study built a WRF-LES system and scaled down to 40 m horizontal resolution based on the large eddy simulation (LES) scheme of WRF (Weather Research and Forecasting) model, and undertook the application study of large eddy simulation on the Qinghai-Xizang Plateau.Based on a strong wind case over the Qinghai-Xizang Plateau, the impacts of LES scheme and terrain elevation data on wind field simulation were evaluated through sensitivity tests.Then, the parameters in the standard sub-grid turbulent stress models of LES scheme were analyzed, and the optimal schemes for wind field simulation on the Qinghai-Xizang Plateau was obtained.Finally, a batch test was conducted to verify the applicability of the optimal schemes to the Qinghai-Xizang Plateau wind field simulation.The test results show that the WRF-LES system with a resolution of 40 m can simulate more precise and accurate wind field information, and the MAE (Mean Absolute Error) of simulated wind speed is reduced by 1.4 m·s-1 and the RMSE (Root Mean Square Error) is reduced by 1.81 m·s-1 compared with the ACM2 scheme; The high-precision ASTER terrain data can also improve the effect of wind field simulation, and the error is approximately deduced by 0.2 m·s-1; The LES scheme that use 1.5-order turbulent flow energy scheme and set parameter coefficient 0.1 has the best simulation result, and the MAE is 1.56 m·s-1 and RMSE is 2.06 m·s-1; The batch test verifies that the large eddy simulation scheme is fit for the wind simulation on the Qinghai-Xizang Plateau, and the wind field simulation results in the 40 m resolution is significantly better than in the mesoscale resolution.The result shows that WRF-LES system can provide accurate wind field information for the parachute landing on the plateau.
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