Optimization of cycloidal water turbine and the performance improvement by individual blade control

Hwang, In Sik; Lee, Yun Han; Kim, Seung Jo

doi:10.1016/j.apenergy.2008.11.009

Cited by 130 publications

(68 citation statements)

References 5 publications

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“…To improve the efficiency, Hwang optimized a 2D Hrotor using a RANS solver and the k-epsilon turbulence model (Hwang, Lee, & Kim, 2009). Hwang showed that the performance can be improved by 25% with an optimized pitching angle motion.…”

Section: Engineering Applications Of Computational Fluid Mechanicsmentioning

confidence: 99%

Numerical investigation of vortex dynamics in an H-rotor vertical axis wind turbine

Chen

Lian

2015

Engineering Applications of Computational Fluid Mechanics

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We study the vortex dynamics of a two-dimensional H-rotor wind turbine using a Navier-Stokes solver. The k-ε turbulence model with the wall function is used as the turbulence closure. A sliding mesh technique is employed to handle the blade rotation. The vortex-blade interaction is systematically investigated and its influence on the force generation is discussed. Our simulations show that the vortex-blade interaction largely depends on the solidity and tip speed ratio. We further study the impact of solidity on the turbine performance. Our simulations show that the peak torque per blade decreases with the solidity while the peak torque azimuthal angle increases with the solidity. Our simulations also show that the increase in the azimuthal angle is more significant at low tip speed ratios than at high tip speed ratios. The impact of blade thickness is studied. Our simulations show that a thicker airfoil has a higher torque coefficient than a thinner airfoil. However, because for the thinner airfoil its peak torque occurs at a high tip speed ratio, the thinner airfoil has an overall higher power coefficient than the thicker airfoil.

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Section: Engineering Applications Of Computational Fluid Mechanicsmentioning

confidence: 99%

Numerical investigation of vortex dynamics in an H-rotor vertical axis wind turbine

Chen

Lian

2015

Engineering Applications of Computational Fluid Mechanics

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“…The velocity at the rotor disk, , is given by (1) where is the free-stream velocity and is the axial flow induction factor. The tangential velocity of a blade element, , is given by (2) where is the angular velocity of the blade. When this velocity component is combined with the expression for the tangential velocity of the wake the result is the net tangential flow velocity experienced by a blade element, , which is…”

Section: Stream-tube Modelmentioning

confidence: 99%

“…Additionally, the power output from a typical horizontal axis tidal turbine is significantly greater than for a wind turbine of similar dimensions and comparable fluid flow velocities, due to water being over 800 times denser than air [2]. In spite of these inherent advantages, tidal current turbine technology is still in its infancy, with the world's first large scale commercial tidal turbine only having been connected to the grid as recently as 2008 by Sea Generation Ltd [3].…”

Section: Introductionmentioning

confidence: 99%

Design of composite tidal turbine blades

et al. 2013

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Tidal turbine blades are subjected to significant thrust and torsional loadings due to the high density of the seawater in which they operate. These thrust loadings lead to high bending moments at the blade root, which can prove to be a serious design constraint for these devices and can have implications with respect to cost-effectiveness and scalability. This work presents a combined hydrodynamic-structural design methodology for a commercial scale (1.5 MW) tidal turbine. A hydrodynamic analysis of the blade is carried out to determine force distributions along the blade span under normal and extreme operating conditions. Using output from the hydrodynamic model, a pre-processor for computing blade structural properties is used to determine the strain distribution along the blade spar caps. The strain distributions from this analysis are then compared with a finite element model of the blade which is then used to compare the structural performance of glass fibre reinforced polymer (GFRP) and carbon fibre reinforced polymer (CFRP) as spar cap materials.

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“…Numerical investigations on flow curvature effects were conducted by Coiro et al [20], 2 Advances in Mechanical Engineering and he argued the difference between DMS model and VAT-VOR3D code. Hwang et al proposed a cycloidal water turbine with individual blade pitch control [21], along with optimized cycloidal motion for better performance obtained from CFD simulations.…”

Section: Introductionmentioning

confidence: 99%

Aerodynamic Performance Prediction of Straight-Bladed Vertical Axis Wind Turbine Based on CFD

Zhang

Liang

Liu

et al. 2013

Advances in Mechanical Engineering

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Numerical simulation had become an attractive method to carry out researches on structure design and aerodynamic performance prediction of straight-bladed vertical axis wind turbine, while the prediction accuracy was the major concern of CFD. Based on the present two-dimensional CFD model, a series of systematic investigations were conducted to analyze the effects of computational domain, grid number, near-wall grid, and time step on prediction accuracy. And then efforts were devoted into prediction and analysis of the overall flow field, dynamic performance of blades, and its aerodynamic forces. The calculated results agree well with experimental data, and it demonstrates that RNG k-turbulent model is great to predict the tendency of aerodynamic forces but with a high estimate value of turbulence viscosity coefficient. Furthermore, the calculated tangential force is more dependent on near-wall grid and prediction accuracy is poor within the region with serious dynamic stall. In addition, blades experience mild and deep stalls at low tip speed ratio, and thus the leading edge separation vortex and its movement on the airfoil surface have a significant impact on the aerodynamic performance.

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Optimization of cycloidal water turbine and the performance improvement by individual blade control

Cited by 130 publications

References 5 publications

Numerical investigation of vortex dynamics in an H-rotor vertical axis wind turbine

Numerical investigation of vortex dynamics in an H-rotor vertical axis wind turbine

Design of composite tidal turbine blades

Aerodynamic Performance Prediction of Straight-Bladed Vertical Axis Wind Turbine Based on CFD

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