Wind Tunnel Experimental Research And Numerical Simulation Of Flow Field Characteristics Of Atmospheric Boundary Layer

Wind power generation is currently the most effective way of wind energy utilization,and wind turbine is located in atmospheric boundary layer(ABL).Therefore,atmospheric boundary layer is directly related to power generation efficiency,operating lifetime,and noise influence of wind turbine.The research on the flow field characteristics of atmospheric boundary layer is the basis concerning the wind turbine engineering application.This paper experimental simulates the mean velocity,turbulence intensity,integral length scale,and wind power spectrum of atmospheric boundary layer in the wind tunnel.The influence mechanism of the barriers,spires,and cubes on the flow field characteristics of the boundary layer is discussed,and the target terrain type is reached.In addition,as a supplement to the wind tunnel experiment,the "numerical wind tunnel" model is set up,and the numerical calculation of the boundary layer flow field is carried out.Then the numerical results are evaluated by the experimental results.The main work and research results are as follows:(1)Barriers were added to the original combination of spires and cubes to improve wind tunnel experimental simulation conditions.12 different configurations were tested in this experiment by adjusting the turbulence devices' position,and the influence mechanism of spires,cubes,and barriers on the boundary layer was analyzed respectively.The results show that spires are the most critical factor for turbulence generation;cubes can influence the boundary layer flow field up to 6 ~ 8 times of its height;downstream-barriers can significantly increase the turbulence intensity,improve the integral length scale in the lower part of the boundary layer,and do contribute to the distribution of pulsed wind energy in the frequency domain.(2)The terrain type was obtained by comparing the wind velocity profile index between the experimental results and the corresponding standards.Then,the simulated terrain type was further verified by taking the geometric similarity into account and contrasting with international standard ASCE7.It shows that the combination of spires,downstream-cubes and downstream-barriers can well achieve the simulation of terrain B under the scale factor 1?267 in the wind tunnel.(3)The numerical wind tunnel was calculated by using the standard k-? two-equation model with the enhanced wall treatment.The comparison of the numerical calculation results with the experimental measurement data shows that their wind speed profiles are basically consistent.In addition,the velocity contours intuitively present the obstruction effect of the spires,the disturbance of the barriers to the flow,and the effect of the cubes to the lower part of the flow field.