Influence Of Wind Speed And Regional Scale On Simulation Results Of Vertical Axis Drag-Type Wind Turbine

Energy is the basis for human survival and development.Now the world's population continues to increase,the consumption of energy is increasing.The conventional energy sources are mainly petroleum,coal and natural gas,most of them are in the low utilization rate,and will produce the acid rain,the greenhouse which will effect environmental pollution.In order to solve these problems.Humans are actively looking for clean energy,such as nuclear energy,solar energy,wind energy and so on.Wind energy is inexhaustible.It has the advantages of no pollution and abundant reserves.The wind turbine is a device that converts wind energy into mechanical energy.Therefore,the research of wind turbine has received extensive attention.This paper mainly studies the five-blade vertical axis drag type wind turbine.By using the method of numerical simulation CFD and FLUENT software for numerical simulation.The sliding mesh technology,the SST k-? turbulence model,PISO algorithm,and QUICK difference scheme are used in the calculations.The main contents of this article are:what are the regular patterns of the flow velocity relative to the outlet boundary standard error,torque coefficient,power,wind energy utilization rate of wind turbine,and the optimum condition,when the wind speed is in 6m/s,7m/s,8m/s,9m/s,10m/s and 12m/s,the calculation areas(HxL)are 70m×70m,70m×140m,70mx210m,70m×350m,the speeds and the length of simulation area are different.The result shows:The simulation results of the performance of wind turbine is affected by entrance wind speed field on the boundary and calculation of region size.The wind energy utilization rate of the calculation area of 70mx 350m is bigger than the calculation area of 210m×70m,when flow entrance boundary wind speed is the same in low wind speed areas(the wind speed is less than 8m/s).While in the high wind speed region,the wind energy utilization rate of the two region is similar.under the condition that the setting of outlet velocity relative error is confirmed when the wind speed increases,the required length of the simulated area should be increased.The wind speed respectively is 6m/s,7m/s,8m/s,9m/s,lOm/s,12m/s,when calculating the area is 70m×210m,in the best conditions of the wind turbine,the wind energy utilization rate respectively is 19.45%,22.80%,24.88%,26.23%,27.04%,27.89%;and when the calculation area is 70m×350m,in the best conditions of the wind turbine,wind energy utilization rate respectively is 20.39%,23.36%,25.21%,26.31%,27.12%,27.96%;Wind energy utilization rate increases gradually with the increase of wind speed for the calculation of the same area,but the growth rate slows down,and Wind energy utilization rate is gradually close to 30%.