An experimental investigation into performance characteristics of H-shaped and Savonius-type VAWT rotors

Wekesa, David Wafula; Saoke, Churchill Otieno; Kamau, Joseph Ngugi

doi:10.1016/j.sciaf.2020.e00603

Cited by 8 publications

(4 citation statements)

References 36 publications

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“…Power coefficients with the corresponding TSR were calculated and compared for both blade types. According to Wekesa et al [6], the power coefficient (C p ) is a dimensionless quantity, which is often used to compare the power performance of wind turbine rotors. In this study, C p has been used to give measure of the magnitude of power extractable in wind using Styrofoam and aluminium rotor blades.…”

Section: Results Discussion and Validationmentioning

confidence: 99%

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Design and Optimization of a Wind Turbine for Rural Household Electrification in Machakos, Kenya

Muchiri

Kamau

Wekesa

et al. 2022

Journal of Renewable Energy

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Machakos is an area characterized by low wind speeds in the range of 0.5 m/s to 5 m/s with an annual average wind speed of 3.5 m/s. Maximum power generation from wind requires the appropriate design of the conversion system. In this study, two HAWT rotor blades were fabricated using Styrofoam and aluminium with a pitching mechanism to maximize power. The system was tested in a wind tunnel environment at a wind speed range of 0 m/s−20 m/s. RPMs and torque were measured and then used to calculate the TSR and power coefficients at different pitching angles. Energy optimization was performed by varying the pitch angles from 0 to 40 degree and rotational speeds, blade shape, and also a variation of blade materials. The analysis of tip speed ratios showed positive skewness implying high potential for significant energy generation at low wind speeds. At the rated wind speed of 5 m/s, Styrofoam blades performed optimally at a pitch angle of 20 degree with a tip speed ratio (TSR) of 2.1 corresponding to a Cp of 0.465. This translates to 238 W of power. Aluminium type performed optimally at a pitch angle of 15 degree with a TSR of 1.9 corresponding to a CP of 0.431, a power estimate of 220 W. These findings showed that Styrofoam blades were more effective and thus suitable for application in wind systems. The understanding gained from this study could be useful to the HAWT research community and can be extended to the turbine designs for small-scale microgrids and utility applications.

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Section: Results Discussion and Validationmentioning

confidence: 99%

“…e two renewables also o er the potential to mitigate the ever-increasing demand for clean energy [5,6]. Of late, wind energy is one of the most developing areas in renewable energy research, accounting for approximately 40% of the total primary energy utilization [7,8].…”

Section: Introductionmentioning

confidence: 99%

Design and Optimization of a Wind Turbine for Rural Household Electrification in Machakos, Kenya

Muchiri

Kamau

Wekesa

et al. 2022

Journal of Renewable Energy

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“…Figure 4b shows our small 10 kW VAWT wind tree that combines 33 VAWTs (1 VAWT is rated at 300 W). The blades are stacked pairs of Savonius and H-Darrieus blades, which show a performance power coefficient (Cp) of around 0.2 [18].…”

Section: Wind Turbine Structurementioning

confidence: 99%

A Novel 10 kW Vertical Axis Wind Tree Design: Economic Feasibility Assessment

et al. 2021

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A novel, small-scale vertical axis wind turbine tree was designed using turbines combining both Darrieus and Savonius blades. We tested for economic viability using wind data collected at a site in Surat Thani, Thailand. The Weibull distribution and Monte Carlo modeling with financial indices (Levelized Cost of Electricity (LCOE), Net Present Value (NPV), Internal Rate of Return (IRR), and Simple Payback Period (SPP)) were used to analyze data. We found that monthly mean wind speeds varied from 2.35 m/s in October to 2.84 m/s in February, corresponding to a wind power of 28.43 W/m2 and 42.68 W/m2. The average annual power output was 1446.1 kWh for May 2019 to April 2021. Results show that for turbine cut-in to cut-out speeds (2 m/s to 15 m/s), the prototype has potential economic feasibility (NPV > 0 for 64.93%), although the small capacity of the wind tree, in combination with the low average wind speed at the Surat Thani test site, showed a lack of economic viability at this specific location (NPV = USD − 20,946.29). A higher-wind-speed location (Chiang Mai) showed viability, especially at a 10 m height (NPV > 0 for 84.83%). We discuss potential conditions that would make broader use of the prototype feasible.

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“…Further results showed similar increase in the C p values of the hybrid VAWT is also observed for other wind speed. Wekesa et al [37] experimentally investigated the performance of VAWT rotors i.e. H-Darrieus and Savonius rotor.…”

Section: Hybrid Vertical Axis Wind Turbinementioning

confidence: 99%

Design and Testing of Building Integrated Hybrid Vertical Axis Wind Turbine

Gwani¹,

Kangiwa²,

Wisdom³

2021

JEEE

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Building integrated wind turbine are considered as part of a group of technologies that are suitable for domestic micro-energy generation. Darrieus and Savonius turbines work efficiently in the urban environment at low wind speed, the Savonius rotor is self-starting and creates high torque but has low efficiency, while the Darrieus rotor is very efficient but does not self-start easily. Thus, the combination of these rotors as hybrid system would help to improve the overall efficiency of the wind turbines. The aim of this paper was to design, fabricate and experimentally investigate the performance of hybrid Vertical Axis Wind Turbine (VAWT) on residential buildings. A building model with gable rooftop was design and fabricated for use in testing of the hybrid VAWT. The height of the hybrid VAWT was paced at Y = 150 mm above the rooftop. The results obtained from the studies showed that the hybrid VAWT mounted on the building rooftop yield up to 63% more energy compared to the bare-hybrid VAWT (without building). Similar improvement in performance of the hybrid VAWT is also observed in the rotational speed, mechanical power and the coefficient of torque, where the building integrated hybrid VAWT outperformed the bare-hybrid VAWT. Thus the results indicate that urban buildings are suitable for the mounting of the hybrid VAWT.

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An experimental investigation into performance characteristics of H-shaped and Savonius-type VAWT rotors

Cited by 8 publications

References 36 publications

Design and Optimization of a Wind Turbine for Rural Household Electrification in Machakos, Kenya

Design and Optimization of a Wind Turbine for Rural Household Electrification in Machakos, Kenya

A Novel 10 kW Vertical Axis Wind Tree Design: Economic Feasibility Assessment

Design and Testing of Building Integrated Hybrid Vertical Axis Wind Turbine

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