CFD Numerical Simulation Of Wind Field Over Complex Terrain

With the “the Belt and Road Initiatives” and the “13th Five-Year Plan”,activities such as infrastructure construction and wind resource development in complex terrain areas have become an inevitable requirement for economic and social development.Computational fluid dynamics(CFD)numerical simulation is an effective means to master the characteristics of complex terrain wind field.Compared with the field measured and wind tunnel experimental,it has the advantages of intuitionism,high efficiency,short period and low cost,and attracted the attention of more and more engineers.In view of the fact that the mountain terrain wind field is more complex and variable than the typical mountain wind field,it is difficult to meet the current development and construction needs for the development and construction of the mountainous terrain area only by relying on the regulations of the building structure load specification.Therefore,in order to better serve the economic construction of the society,it is more intuitive and effective to understand the wind field characteristics of complex terrain,make up for the shortcomings of current load specifications,and provide more for wind resource development,urban wind environment research,and atmospheric pollutant diffusion research.Accurate and effective guidance is necessary to carry out numerical simulation studies of complex terrain wind fields.In this paper,based on the standard k-? turbulence model,the equilibrium atmospheric boundary layer is studied.The atmospheric boundary layer is realized by adding the source term in the transport equation of turbulent kinetic energy and dissipation rate and applying shear stress to the bottom and top boundaries.Good self-sustaining properties.Then,based on the complex terrain around the Siu Ho Wan(SHW)observatory in Hong Kong,the high-precision complex terrain model is established and high-quality meshing is carried out.Numerical simulations of different wind-down complex terrain wind fields are carried out,and the simulation results will be obtained.The wind field data at SHW is compared with wind tunnel test and field measured data to verify the validity and reliability of the CFD numerical simulation means in this chapter.Then the extension of complex terrain boundaries and the complex terrain range and computational domain size are further discussed.Different complex terrain boundary expansion methods are used to smoothly transition the digital terrain boundary,and the complex terrain flow under different expansion modes is compared and analyzed.The field characteristics,and the influence of the complex terrain range and the calculation domain size on the characteristics of the complex terrain flow field are discussed.It provides a reference for the terrain boundary processing and terrain range selection and calculation domain size setting in the numerical simulation of complex terrain wind field.Finally,in order to apply more realistic inflow conditions in the numerical simulation of complex terrain wind field,maintain the geomorphological features of a larger range of original terrain,break through the limitations of current computer hardware level and improve the efficiency and accuracy of numerical simulation of complex terrain,the numerical simulation is implemented based on IMP,the calculation domain of the complex terrain wind field simulation is divided into upper and lower levels in the inflow direction and the results of the simulation speed and turbulence characteristics of the upper complex terrain calculation domain are extracted by FLUENT and used as the next level.Calculate the inlet boundary conditions of the domain to achieve fast and high-precision numerical simulation of complex terrain wind fields.