摘要
The multi-rotor approach adds a significant improvement over conventional,single rotor wind turbines by utilizing the wind side-flow that is lost by conventional turbines.The power output can be increased by as much as 26%over a conventional wind turbine of comparable size.The benefit of the addition of side flow can be easily seen when used with the multi-rotor turbines as shown in this paper.At induction factors of greater than 0.2,a multi-rotor system will begin outputting higher power than the rotors individually.Based on the results as shown in this paper,an optimal induction factor would be between 0.4 and 0.5 to get the greatest benefit of the side flow.The addition of a brimmed diffuser magnified the benefits of the side flow even more by increasing flow through and in front of the rear rotor.Depending on the rotor spacing,rotors in front of the back rotor could see the effects of the diffuser as well.Typically a rotor spacing of one meter or greater is practical depending on the size of the rotor blades.Flow simulation studies supported the benefits of a multi-rotor system and the use of side flow for rotor step sizes of greater than 4 meters.The power increase with the addition of a diffuser was supported by the flow simulation studies as well by showing significant increases in wind power and power.Additionally,according to flow trajectory animations,turbulence as a result of upstream rotating blades appeared to be dampened out because of the diffuser.
