| In order to improve the output power of the wind turbine and capture more wind energy,it is necessary to optimize the aerodynamic performance of the blade and carry out efficient flow control.At present,scholars at home and abroad are committed to improving the aerodynamic performance of wind turbine blades by flow control devices and technologies such as vortex generators and Gurney flaps.Based on the research of flow control technology at home and abroad,this paper studies the combination of passive flow control devices,which provides a new idea for the research of flow control devices.Based on the original model of NREL Phase VI wind turbine,this paper takes five flow control devices of single and double row vortex generators,single and double row wing knives and Gurney flaps as the research objects,and explores the effects of different height parameters of double row vortex generators and different combinations of five flow control devices on the aerodynamic performance of wind turbines.The main contents and research results are as follows:1.The NREL Phase VI wind turbine blade is modeled,meshed and mesh independence verified to ensure the accuracy and feasibility of the numerical simulation method.Secondly,the SST k-ω turbulence model is used to numerically simulate the aerodynamic performance of the Phase VI wind turbine under nine working conditions.The simulation results are compared with the experimental results.It is found that the SST k-ω turbulence model can well reflect the real flow field and aerodynamic conditions of the Phase VI wind turbine.Finally,the aerodynamic characteristics such as pressure coefficient,normal force coefficient and blade surface flow separation of Phase VI wind turbine at different speeds and wind speeds are analyzed.2.Nine double-row vortex generators with different height parameters were installed on the blades of NREL Phase VI wind turbine.The effects of different height parameters of double-row vortex generators on the aerodynamic characteristics of wind turbines under four working conditions of speed 72.1rpm,wind speed 10m/s,13m/s and speed 91 rpm,wind speed 13m/s,15m/s were explored,which laid a foundation for the subsequent flow control combination research.The results show that the 9 different height parameters of double row vortex generators can improve the aerodynamic performance of wind turbine blades and improve the flow field of wind turbine at different speeds and wind speeds.Among them,the case3 combination flow control effect is the best,which can better improve the aerodynamic performance of the blade and suppress the separation flow.When the speed is 72.1rpm,the wind speed is 10m/s and the speed is 91 rpm,the wind speed is 15m/s,the output torque is 14.18% and 24.26%higher than the original model.3.Five kinds of passive flow control devices,such as single and double row vortex generators,single and double row wing knives and Gurney flaps,were installed on NREL Phase VI wind turbine blades.It was found that the flow control mechanisms of vortex generators,wing knives and Gurney flaps were different,so the effect and focus of action were different.Under the condition of mainly considering improving the output torque of the wind turbine,the effect of the double-row vortex generator is the best,followed by the Gurney flap,the single-row vortex generator,and the single-row blade,and finally the double-row blade.When the speed is 72.1rpm and the wind speed is 10m/s,the output torque is increased by 14.18%,12.71%,9.17%,6.78% and-5.78%respectively compared with the original model.Therefore,in practical engineering applications,the passive flow control device should be reasonably selected to improve the overall aerodynamic performance of the wind turbine as much as possible.4.Five kinds of passive flow control devices,single-row and double-row vortex generators,single-row and double-row wing knives and Gurney flaps,were studied respectively.It was found that the effects of flow control combinations were different.Among them,the combination of single-row and double-row vortex generators and single-row wing knives,and the combination of single-row and double-row vortex generators and Gurney flaps combined the advantages of the two control devices.On the basis of single-row vortex generators,double-row vortex generators,single-row wing knives and Gurney flaps,the output torque of wind turbines can be further improved,the flow area of blade attachment can be increased,the flow separation can be better suppressed,and the aerodynamic performance of wind turbines can be improved.When the speed is 72.1rpm and the wind speed is 10m/s,the output torque is increased by 13.79%,15.64%,15.10% and 18.41% respectively compared with the original model.In this paper,the effects of different height parameters of double-row vortex generators and different combinations of five flow control devices on the aerodynamic performance of wind turbines are studied.The optimal height parameter combination of double-row vortex generators,namely case3 combination,is obtained.At the same time,the combination of single-row,double-row vortex generators and single-row wing blades,single-row,double-row vortex generators and Gurney flaps are obtained.The flow control combination installation scheme with good effect provides a corresponding reference for subsequent research on different flow control combinations. |
