A Review of Darrieus Water Turbines

Rehman, Wajiha; Rehman, Fatima; Malik, Muhammad Zain

doi:10.1115/power2018-7547

Cited by 3 publications

(3 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A typical cross-flow turbine is made of a runner with a horizontal shaft, having a certain number of blades (from 11 up to 37) [32], arranged radially and tangentially. At the core of the turbine, there is a rotor whose blades have a circular cross-section [33]. Cross flow turbines can achieve high efficiency easily, such as 80% or above [31], whereas vertical turbines for freestreams, like Savonius and Darrieus, cannot reach such high efficiency.…”

Section: The Designmentioning

confidence: 99%

See 1 more Smart Citation

A CFD Analysis for Novel Close-Ended Deflector for Vertical Water Turbines

et al. 2022

View full text Add to dashboard Cite

The effects of climate change are growing more and more evident, and this is caused by the increase in CO2 emissions. Fossil fuel exhaustion and the need for electricity in remote areas have encouraged researchers to advance and develop the renewable energy sector. One type of clean energy technology is vertical water turbines that have low efficiency. This paper aims to design and simulate a novel close-ended, guided deflector to improve the efficiency of vertical turbines. This research used the dynamic mesh technique to evaluate the concept after the deflector was designed, and a grid independence study, a boundary sensitivity study, and a timestep sensitivity study were implemented to ensure the accuracy of the results. Then, we used the sliding mesh model to determine the performance of four rotors. The results from the dynamic mesh model showed that the straight rotor with the proposed deflector was not suitable for operating in the deflector, and the concept is static and does not rotate. However, the others showed a valid concept in the proposed deflector. For the sliding mesh technique, the results indicated a common trend: all the rotors’ performances increased when tip speed ratio (TSR) increased, and the highest amount of the power coefficient (Cp) was found at higher TSRs, such as 1.3 and 1.4, with around 0.45 in the cross flow type. A three-dimensional simulation was conducted of the cross flow type with the proposed deflector, and a similar trend was found. Nevertheless, around a 5% difference was found between the 3D and 2D results for cross flow. The deflector can significantly improve the performance after 0.7 TSR to reach over 0.42 Cp at 1.3 TSR, whereas, without the deflector, the performance reduces to approximately 0.1 Cp at the same TSR.

show abstract

Section: The Designmentioning

confidence: 99%

“…The simulation was performed, taking into consideration the Malaysian environment, with an inlet velocity of 0.56 m/s, the lowest water velocity in Malaysia [32]. The maximum mechanical power in Watts contained in a freestream is given by [33][34][35]:…”

Section: The Designmentioning

confidence: 99%

A CFD Analysis for Novel Close-Ended Deflector for Vertical Water Turbines

et al. 2022

View full text Add to dashboard Cite

show abstract

“…The CFD Analyze 2D Model of the Savonius-Darrieus Turbine with variations of velocity for the environment and the angle of attack of the hydrofoil. The Savonius-Darrieus Turbine was chosen due to overcome negative start off torque problem in the Darrieus Turbine [9] [10]. Basically, this research by changing the Darrieus Turbine to the Savonius-Darrieus Turbine aim for seeing the effect of Savonius Rotor addition with an angle of attack variation [11] [12].…”

Section: Introductionmentioning

confidence: 99%

Design Modeling of Savonius-Darrieus Turbine for Sea Current Electric Power Plant

Metheny

Permatasari

Annas

2020

Sinergi

View full text Add to dashboard Cite

Turbines convert the kinetic energy of ocean currents into electrical energy produced by the sea current electric power plant. This study aims to design a power generator turbine modeling that is carried out using the Computational Fluid Dynamic (CFD) approach by comparing the geometric performance based on the angle of attack and the Tip Speed Ratio (TSR) value of the Savonius-Darrieus Turbine. Having done several trials and errors during collecting the data, the value of the TSR 1.427; 2.853; 4.28; 5; and 5.7 is proposed. Here, the NACA 0018 series has been adopted on the current design of Savonius-Darrieus Turbine. The turbine has three blades, length of the span 357 mm, the diameter of turbine 428 mm, and length of the hydrofoil chord 40 mm. Effect of various angle of attacks from 0°up to 10° has been taken into account in the computational to obtain the coefficient power for each variation. The results revealed that the turbine with an angle of attack of 5°and TSR value of 5.0 has higher power coefficient value by 0.469 as compared with its angle of attack of 10°. It should be noted here that the increase of the angle of attack up to 10° resulted in a significant reduction of the power coefficient value of 0.206 as the value of TSR about 4.28. The addition of the Savonius Rotor results in increasing efficiency of the turbine for sea current applications.

show abstract