The traditional RANS turbulence parameterization scheme is modified on the basis of the Computational Fluid Dynamics model (Fluent), and the large eddy model (LES) turbulence scheme is selected, then the buoyancy model of temperature stratification is introduced, finally the modified Fluent model is obtained.The Weather Research and Forecasting model (WRF) and WRF coupled Fluent before and after modified are used to simulate the wind speed and direction of the 4 months from December 2010 to March 2011 in Jishan wind station in Poyang Lake region, Jiangxi and the evolution of the flow field and the temperature field near Jishan station in March 6, 2011.According to the comparison of the observation data, it is found that: After coupling Fluent, the better WRF simulation result of the wind speed and wind direction in Jishan station is obtained.Compared with coupling original Fluent (Example 1), WRF coupling modified Fluent (Example 2) can provide more accurate simulation result of the wind speed and wind direction at each height in Jishan station.The average error of WRF, Example 1 and Example 2 for the 4 months 70 m height average wind speed are 3.963, 2.727 and 2.224 m·s-1 respectively.The Matching ratio to the observed wind direction rose of Example 2 is higher than Example 1 at 70 m height mostly.Example 2 not only can simulate the thermal buoyancy effect under the daytime unstable state and the spatial inhomogeneous and higher turbulent kinetic energy, but also can simulate the temperature inversion of the atmospheric boundary layer at night, while Example 1 can not.All the above results indicate that after the modification of Fluent model, the simulation result of the method that WRF coupled Fluent to the wind field near Jishan Station is improved.To sum up, this research provides a new method and basis for the prediction of the atmospheric flow field in the bottom of atmospheric boundary layer and the multiscale coupling simulation, and has also laid the foundation for the development and improvement of Fluent model in the future .
Jiarong ZHANG
,
Xueling CHENG
. Numerical Simulation of Wind Field in Complex Terrain based on CFD Downscaling[J]. Plateau Meteorology, 2020
, 39(1)
: 172
-184
.
DOI: 10.7522/j.issn.1000-0534.2019.00005
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