To reduce the vibration and aerodynamic noise of wind turbines,a new design is proposed relying on a blade with a bifurcated apex or tip.The performances of this wind turbine wheel are tested at the entrance of a DC(d...To reduce the vibration and aerodynamic noise of wind turbines,a new design is proposed relying on a blade with a bifurcated apex or tip.The performances of this wind turbine wheel are tested at the entrance of a DC(direct-action)wind tunnel for different blade tip angles and varying centrifugal force and aerodynamic loads.The test results indicate that the bifurcated apex can reduce the vibration acceleration amplitude and the vibration fre-quency of the wind wheel.At the same time,the bifurcated apex can lower the maximum sound pressure level corresponding to the rotating fundamental frequency of the wind wheel.According to all thesefindings,the tip angle of the bifurcated apex is the main factor enhancing the effect of the modification.展开更多
This paper posits that a low-speed wind turbine design is suitable for harnessing wind energy in Africa.Conventional wind turbines consisting of propeller designs are commonly used across the world.A major hurdle to u...This paper posits that a low-speed wind turbine design is suitable for harnessing wind energy in Africa.Conventional wind turbines consisting of propeller designs are commonly used across the world.A major hurdle to utilizing wind energy in Africa is that conventional commercial wind turbines are designed to operate at wind speeds greater than those prevalent in most of the continent,especially in sub-Sahara Africa(SSA).They are heavy and expensive to purchase,install,and maintain.As a result,only a few countries in Africa have been able to include wind energy in their energy mix.In this paper,the feasibility of a novel low-speed wind turbine based on a Ferris wheel is demonstrated for low wind speed applications in Africa.The performance of Ferris wheel wind turbines(FWT)with 61m(200 ft),73m(240 ft)and 104m(341 ft)diameter rims and an 800kW generator are evaluated for selected African cities.The research also compares the Weibull wind distribution of the African cities of interest.A comparison between the FWT and the conventional commercial wind turbines in terms of efficiency,rated wind speed,cost,performance,and power to weight is included.Results show that the FWT has the potential for economic power generation at rated wind speeds of 6.74m/s,which are lower than the average of 12 m/s for conventional wind turbines and have lower power to weight ratios of 5.2 kW/tonne as compared to 6.0-9.2 kW/tonne for conventional wind turbines.展开更多
基金supported by the National Natural Science Foundation Project under Grant Numbers[51966018,51466015].
文摘To reduce the vibration and aerodynamic noise of wind turbines,a new design is proposed relying on a blade with a bifurcated apex or tip.The performances of this wind turbine wheel are tested at the entrance of a DC(direct-action)wind tunnel for different blade tip angles and varying centrifugal force and aerodynamic loads.The test results indicate that the bifurcated apex can reduce the vibration acceleration amplitude and the vibration fre-quency of the wind wheel.At the same time,the bifurcated apex can lower the maximum sound pressure level corresponding to the rotating fundamental frequency of the wind wheel.According to all thesefindings,the tip angle of the bifurcated apex is the main factor enhancing the effect of the modification.
基金This research is funded by the African Centre of Excellence,Energy for Sustainable Development,University of Rwanda,through the World Bank ACE II Program.
文摘This paper posits that a low-speed wind turbine design is suitable for harnessing wind energy in Africa.Conventional wind turbines consisting of propeller designs are commonly used across the world.A major hurdle to utilizing wind energy in Africa is that conventional commercial wind turbines are designed to operate at wind speeds greater than those prevalent in most of the continent,especially in sub-Sahara Africa(SSA).They are heavy and expensive to purchase,install,and maintain.As a result,only a few countries in Africa have been able to include wind energy in their energy mix.In this paper,the feasibility of a novel low-speed wind turbine based on a Ferris wheel is demonstrated for low wind speed applications in Africa.The performance of Ferris wheel wind turbines(FWT)with 61m(200 ft),73m(240 ft)and 104m(341 ft)diameter rims and an 800kW generator are evaluated for selected African cities.The research also compares the Weibull wind distribution of the African cities of interest.A comparison between the FWT and the conventional commercial wind turbines in terms of efficiency,rated wind speed,cost,performance,and power to weight is included.Results show that the FWT has the potential for economic power generation at rated wind speeds of 6.74m/s,which are lower than the average of 12 m/s for conventional wind turbines and have lower power to weight ratios of 5.2 kW/tonne as compared to 6.0-9.2 kW/tonne for conventional wind turbines.
