Three-dimensional numerical simulations of straight-bladed vertical axis tidal turbines investigating power output, torque ripple and mounting forces

Marsh, Philip; Ranmuthugala, Dev; Penesis, Irene; Thomas, Giles

doi:10.1016/j.renene.2015.04.014

Cited by 102 publications

(62 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Although the 2D CFD model cannot reflect all the hydrodynamic characteristics of the VAT and will ignore some parasitic drag forces [30], it has been pointed out that the 2D model is suitable for the initial study to save computational cost and time [23]. Considering that the numerical simulation of the self-starting of a VAT is still in a preliminary stage, we decided to use the 2D model in this study.…”

Section: Numerical Set-upmentioning

confidence: 99%

Numerical Study on Self-Starting Performance of Darrieus Vertical Axis Turbine for Tidal Stream Energy Conversion

Liu

Shi

2016

Energies

View full text Add to dashboard Cite

Self-starting performance is a key factor in the evaluation of a Darrieus straight-bladed vertical axis turbine. Most traditional studies have analyzed the turbine's self-starting capability using the experimental and numerical data of the forced rotation. A 2D numerical model based on the computational fluid dynamics (CFD) software ANSYS-Fluent was developed to simulate the self-starting process of the rotor at constant incident water-flow velocities. The vertical-axis turbine (VAT) rotor is driven directly by the resultant torque generated by the water flow and system loads, including the friction and reverse loads of the generator. It is found that the incident flow velocity and the moment of inertia of the rotor have little effect on the averaged values of tip-speed ratios in the equilibrium stage under no-load conditions. In the system load calculations, four modes of the self-starting were found: stable equilibrium mode, unstable equilibrium mode, switch mode and halt mode. The dimensionless power coefficient in the simulations of passive rotation conditions is found to be, on average, 38% higher than those achieved in the simulations of forced rotation conditions.

show abstract

Section: Numerical Set-upmentioning

confidence: 99%

Numerical Study on Self-Starting Performance of Darrieus Vertical Axis Turbine for Tidal Stream Energy Conversion

Liu

Shi

2016

Energies

View full text Add to dashboard Cite

show abstract

“…These 2D models are often used due to their significantly reduced computational requirements when compared to Three-Dimensional (3D) models. However, these 2D approaches often significantly over predict maximum power output [4][5][6][7] due to the highly 3D nature of turbine hydrodynamic flow due to blade and strut joint and blade tip losses [8]. Numerical simulations are also commonly performed using fully turbulent models [4][5][6][7][8], again due to their computational efficiency.…”

Section: Introductionmentioning

confidence: 99%

“…However, these 2D approaches often significantly over predict maximum power output [4][5][6][7] due to the highly 3D nature of turbine hydrodynamic flow due to blade and strut joint and blade tip losses [8]. Numerical simulations are also commonly performed using fully turbulent models [4][5][6][7][8], again due to their computational efficiency. However, the influence of laminar-to-turbulent flow transition on power output predictions is unknown, and may be significant as turbines can operate in low Reynolds number dominated flows [8].…”

Section: Introductionmentioning

confidence: 99%

“…Numerical simulations are also commonly performed using fully turbulent models [4][5][6][7][8], again due to their computational efficiency. However, the influence of laminar-to-turbulent flow transition on power output predictions is unknown, and may be significant as turbines can operate in low Reynolds number dominated flows [8]. For turbulence modeling the k-ω Shear Stress Transport (k-ω SST) model is prevalent [2,4,[8][9][10][11][12][13][14], due to its ability to model both free stream and wall bounded flows accurately.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The influence of turbulence model and two and three-dimensional domain selection on the simulated performance characteristics of vertical axis tidal turbines

et al. 2017

Self Cite

View full text Add to dashboard Cite

ABSTRACT:The influence of Computational Fluid Dynamics (CFD) modeling techniques on the accuracy of vertical axis turbine power output predictions was investigated. Using Two-Dimensional (2D) and Three-Dimensional (3D) models, as well as the Baseline-Reynolds Stress Models (BSL-RSM) model and the k-ω Shear Stress Transport (k-ω SST) model in its fully turbulent and laminar-to-turbulent formulation, differences in power output modeling accuracy were evaluated against experimental results from literature. The highest correlation with experimental power output was found using a 3D domain model that fully resolved the boundary layer combined with the k-ω SST laminar-to-turbulent model. The turbulent 3D fully resolved boundary layer k-ω SST model also accurately predicted power output for most rotational rates, at a significantly reduced computational cost when compared to its laminar-to-turbulent formulation. The 3D fully resolved BSL-RSM model and 3D wall function boundary layer k-ω SST model were found to poorly simulate power output. Poor output predictions were also obtained using 2D domain k-ω SST models, as they were unable to account for blade tip and strut effects. The authors suggest that 3D domain fully turbulent k-ω SST models with fully resolved boundary layer modeling are used for predicting turbine power output given their accuracy and computational efficiency.  2D CFD models cannot capture blade tip and strut effects resulting in poor power output simulation accuracy  3D CFD models can now accurately capture turbine power output without excessive computation requirements  The k-ω SST turbulence models provide the closest agreement with experimental results  Transition flow modeling is computationally demanding and only increases simulation accuracy at high rotational rates when compared to fully turbulent models  BSL-RSM and k-ω SST Wall Function models poorly simulate power output

show abstract

“…On the other hand, hydrodynamics of cross-flow turbines are very complex due to three different reasons, which cause uncertainty, complex turbulence and flow separation: 1-Changing of angle of attack during each turn. 2-Influence of aerofoil fluctuations on each other, 3-Influence of connecting arms on flow field [3].In cross flow turbines, at low rotational speeds, change of angle of attack effectively alters turbine performance and causes static and dynamic stalls [4]. On the other hand, the performance of the turbine at high speeds is influenced by flow turbulence, turbulence created by the aerofoils, and interactions caused by both of them [5].…”

Section: Introductionmentioning

confidence: 99%

In-Pipe Turbine Design for Turbo Solenoid Valve System

Mutlu¹,

Çakan²

2017

IOSR JMCE

View full text Add to dashboard Cite

Three-dimensional numerical simulations of straight-bladed vertical axis tidal turbines investigating power output, torque ripple and mounting forces

Cited by 102 publications

References 20 publications

Numerical Study on Self-Starting Performance of Darrieus Vertical Axis Turbine for Tidal Stream Energy Conversion

Numerical Study on Self-Starting Performance of Darrieus Vertical Axis Turbine for Tidal Stream Energy Conversion

The influence of turbulence model and two and three-dimensional domain selection on the simulated performance characteristics of vertical axis tidal turbines

In-Pipe Turbine Design for Turbo Solenoid Valve System

Contact Info

Product

Resources

About