Numerical Simulation Of The Effect Of Rough Element Geometric Parameters On Wind Resistance Of Surface Wind Field

In northwest China,there is a vast Gobi with abundant gravel resources.Gravel can be used to cover the sandy surface to reduce the carrying capacity of wind speed near the surface,thus playing an important role in environmental protection.At present,the research on the wind and wind resistance effect of gravel on the sandy surface mainly focuses on field observation experiments and wind tunnel experiments,and the numerical simulation methods are very few.In this paper,the gravel is used as the research background,which is simplified into the regular geometry rough element.The RSM model in ANSYS Fluent software is used to study the wind resistance effect of the geometric parameters of the rectangular rough and hemispherical rough elements on the surface wind field.The advantages and disadvantages of the two models’wind blocking effects are compared to determine the best geometric parameters,which provides a reference for practical applications.The main contents of this paper are as follows:1.This paper reviews the research and development of the wind resistance effect of gravel,zero plane displacement d and dynamic roughness Z₀ at home and abroad.Then,the governing equation for simulating turbulent flow field of rough element and its closed solution methods are introduced in detail.2.Comparing the wind speed profile of the simulation results of this paper with the experimental results of previous scholars and the DNS simulation results,it is found that the coincidence degree is good,indicating the correctness of the numerical simulation method.3.Taking the height h and height spacing ratio of the cuboid rough element jj as geometric parameters,the pressure difference drag?_tp of the rough element in the flow field,the wall drag?_tbb on the top surface of the rough element,the wall drag?_ts on the underlying surface of the flow field,the zero-plane displacement d and the dynamic roughness Z₀ with the variation of geometric parameters and the inlet wind speed U_b are studied under different conditions of uniform inlet wind speed.The dynamic roughness Z₀ is taken as the parameter to judge the wind blocking effect of rough element,and the geometric parameters when the wind blocking effect is the best are determined.4.Based on the research theory of the rectangular parallelepiped element,the flow field characteristics of the hemispherical rough element model are further simulated,and the results are compared with the cuboid.Finally,the wind resistance effect of the hemispherical rough element is qualitatively analyzed.