Large Eddy Simulations on Vertical Axis Hydrokinetic Turbines - Power coefficient analysis for various solidities

Guillaud, Nathanaël; Balarac, Guillaume; Goncalves, Éric; Zanette, Jeronimo

doi:10.1016/j.renene.2019.08.039

Cited by 29 publications

(11 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Seeing that the details of numerical set-up and numerous obtained results can be found in [27], only a short summary is given here. Other extremely useful examples of flow simulations around VAWTs can be found in [28][29][30][31][32][33][34].…”

Section: Flow Simulationmentioning

confidence: 99%

Multi-objective Optimization and Experimental Testing of a Laminated Vertical-Axis Wind Turbine Blade

Trivković

Svorcan

Baltić

et al. 2021

Current Problems in Experimental and Computational Engineering

View full text Add to dashboard Cite

Vertical-axis wind turbines, despite being somewhat uncommon and less efficient renewable energy converters, still offer many advantages to small consumers and possibilities for further improvement. Their rotor is usually made up of fiberglass composite blades that can be optimized both aerodynamically and/or structurally. Although the aerodynamics of vertical-axis wind turbine rotors is unsteady, complex and challenging to simulate, it is possible to make a sufficiently accurate estimation of variable aerodynamic loads acting on the blade and use them for its structural dimensioning. This research combines a multi-objective constrained optimization procedure by particle swarm and finite element method with experimental analyses with the purpose of defining the best blade, i.e. the blade of minimal mass, least tip deflection under the loading case corresponding to the aerodynamically most demanding operational regime, greatest difference between its natural frequencies and rated rotor angular frequency, lowest manufacturing cost and complexity, etc. Imposed constraints also include acceptable failure criteria along the blade. Design variables refer to ply lay-up scheme, i.e. lamina thicknesses and orientations. Final solution, chosen from the obtained Pareto set, was manufactured and experimentally validated. The consistency of strains, measured in several different cases of bending, and corresponding numerical values was mostly below 8%. The study demonstrates the applicability of the employed multi-objective optimization methodology in wind turbine blade design. It also proposes an affordable and structurally reliable composite lay-up scheme specifically designed for small-scale vertical-axis wind turbines.

show abstract

Section: Flow Simulationmentioning

confidence: 99%

Multi-objective Optimization and Experimental Testing of a Laminated Vertical-Axis Wind Turbine Blade

Trivković

Svorcan

Baltić

et al. 2021

Current Problems in Experimental and Computational Engineering

View full text Add to dashboard Cite

show abstract

“…Potential flow analysis using a surface vorticity model is applied to minimize losses in the runner profile. Several other optimization methods related to potential flow analysis of the runner turbomachinery profile were conducted using a viscous vortex lattice method analysis [6], multiphase large eddy simulations [7], [8], computational fluid dynamics analysis [9]- [14] and experimental analysis [15]- [17]. In this work, design validation was implemented to determine performance using computational fluid dynamics analysis ANSYS CFX.…”

Section: Introductionmentioning

confidence: 99%

Design and performance of very low head water turbines using a surface vorticity model algorithm

Subekti

Prawara²,

Susatyo³

et al. 2022

IJPEDS

View full text Add to dashboard Cite

This study explores the numerical optimization of water turbine runner profile performance using a surface vorticity model algorithm. The turbine is designed on a laboratory scale and operates at a net head of 0.09 m, 400 rpm, and a water flow rate of 0.003 m3/s. The initial design of the turbine runner was optimized to minimize losses in the hydrofoil. The optimization algorithm is coded in MATLAB software to obtain the optimal stagger angle that will be used in the water turbine design. Furthermore, design validation was performed using computational fluid dynamics analysis ANSYS CFX to determine the water turbine performance. The settings used in ANSYS CFX include the reference pressure of 1 atm, turbulence model shear stress transport, and inlet boundary conditions using total pressure and static pressure outlet boundary conditions. The computational fluid dynamics analysis reveals that by optimizing the design, the efficiency of the water turbine increases by approximately 2.6%. The surface vorticity model algorithm can be applied to optimize the design of the water turbine runner.

show abstract

“…They are more adapted to simulate the wake of the turbine due to the importance of the 3D flow structures on the wake recovery. Large Eddy Simulations (LES) [26,27] are even more time-consuming but they allow a significant increase in the accuracy of the performance predictions, especially when the turbine blades experience stall. LES is also well adapted to model the wake of a VAT.…”

Section: Introductionmentioning

confidence: 99%

Performance Improvement of a Darrieus Tidal Turbine with Active Variable Pitch

et al. 2021

View full text Add to dashboard Cite

Vertical axis turbines, also called Darrieus turbines, present interesting characteristics for offshore wind and tidal applications but suffer from vibrations and a lower efficiency than the more conventional horizontal axis turbines. The use of variable pitch, in order to control the angle of attack of the blades continuously during their rotation, is considered in this study to overcome these problems. 2D blade-resolved unsteady Reynolds-Averaged Navier–Stokes (RANS) simulations are employed to evaluate the performance improvement that pitching blades can bring to the optimal performance of a three-straight-blade vertical axis tidal turbine. Three pitching laws are defined and tested. They aim to reduce the angle of attack of the blades in the upstream half of the turbine. No pitching motion is used in the downstream half. The streamwise velocity, monitored at the center of the turbine, together with the measurement of the blades’ angle of attack help show the effectiveness of the proposed pitching laws. The decrease in the angle of attack in the upstream half of a revolution leads to a significant increase in the power coefficient (+40%) and to a better balance of the torque generated in the upstream and downstream halves. Both torque and thrust ripples are therefore significantly reduced.

show abstract

Large Eddy Simulations on Vertical Axis Hydrokinetic Turbines - Power coefficient analysis for various solidities

Cited by 29 publications

References 42 publications

Multi-objective Optimization and Experimental Testing of a Laminated Vertical-Axis Wind Turbine Blade

Multi-objective Optimization and Experimental Testing of a Laminated Vertical-Axis Wind Turbine Blade

Design and performance of very low head water turbines using a surface vorticity model algorithm

Performance Improvement of a Darrieus Tidal Turbine with Active Variable Pitch

Contact Info

Product

Resources

About