Experimental Investigation And Numerical Simulation Of A Simplified Tower Shadow Model

Nowadays, wind energy has become one of the most important alternative energies to mitigate the energy shortage problem due to the advantages of rich resources, widely distribution and environment-friendly. The rapid growth of the upstream wind turbine has led to some problems like tower shadow effect, which are aero-dynamic disturbances of the wind flow due to the presence of the tower. Tower shadow leads to a harmful effect on the wind turbine output and the wind turbine structures, and also noise radiation. For a better understanding of tower shadow, A simplified tower shadow model, or the interaction effect between a plate and a circular cylinder was investigated both experimentally and numerically.In the experimental section, The particle image velocimetry(PIV) technique was employed for the research of the interaction region, and for each case the pressure distribution on the cylinder surface was measured by a pressure sensor. The dynamic characteristics of the cylinder surface and the time-averaged flow field of the interaction region were discussed, as well as the turbulent characteristics. Conclusions are drawn out that the interaction effect fades as the plate moving away from the cylinder, the correlation coefficient between the pressure coefficient distributions of cylinder surface with and without plate increases from-0.37 to 0.97, the magnitude of the resultant force fluctuates between 72% and 115% of the original value. The blockage of cylinder affects more on the velocity components than on the turbulent parts.In the numerical part, 2D simplified model was performed by Fluent solver combined with SST k-? turbulent model. The pressure coefficient distribution of the cylinder surface and the velocity and pressure distribution of the computational domain were analysed for each case, the results show that the changes of stagnation point and separation points in simulation fit well with that in experiment, though a bit larger. The plate shear layer shows a greater impact on the cylinder, while the variation of flow pattern in the interaction region is in consistent with experiment.