Evaluation of the unsteady aerodynamic forces acting on a vertical-axis turbine by means of numerical simulations and open site experiments

Pitch regulation plays a significant role in improving power performance and achieving output control in wind turbines. The present study focuses on a novel, pitch-regulated vertical axis wind turbine (VAWT) with inclined pitch axes. The effect of two pitch parameters (the fold angle and the incline angle) on the instantaneous aerodynamic forces and overall performance of a straight-bladed VAWT under a tip-speed ratio of 4 is investigated using an actuator line model, achieved in ANSYS Fluent software and validated by previous experimental results. The results demonstrate that the fold angle has an apparent influence on the angles of attack and forces of the blades, as well as the power output of the wind turbine. It is helpful to further study the dynamic pitch regulation and adaptable passive pitch regulation of VAWTs. Incline angles away from 90° lead to the asymmetric distribution of aerodynamic forces along the blade span, which results in an expected reduction of loads on the main shaft and the tower of VAWTs.

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A Straight-Bladed Vertical-Axis Turbine for Wave Energy Conversion

The Proceedings of the Fluids engineering conference ◽

10.1299/jsmefed.2020.os09-12 ◽

2020 ◽

Vol 2020 (0) ◽

pp. OS09-12

Author(s):

Keisuke KITANO ◽

Yasutaka HAYAMIZU ◽

Takayuki SUZUKI ◽

Shinichi MORITA ◽

Shigeru OHTSUKA ◽

...

Keyword(s):

Energy Conversion ◽

Wave Energy ◽

Vertical Axis ◽

Wave Energy Conversion ◽

Vertical Axis Turbine

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Experimental Study on the Straight-Bladed Vertical-Axis Turbine for Wave Energy Conversion

The Proceedings of Conference of Chugoku-Shikoku Branch ◽

10.1299/jsmecs.2021.59.07a5 ◽

2021 ◽

Vol 2021.59 (0) ◽

pp. 07a5

Author(s):

Keisuke KITANO ◽

Yasutaka HAYAMIZU ◽

Takayuki SUZUKI ◽

Shigeru OHTSUKA ◽

Shinichi MORITA ◽

...

Keyword(s):

Experimental Study ◽

Energy Conversion ◽

Wave Energy ◽

Vertical Axis ◽

Wave Energy Conversion ◽

Vertical Axis Turbine

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The Vertical-Axis Turbine

LEGO Wind Energy ◽

10.1007/978-1-4842-4439-5_3 ◽

2019 ◽

pp. 29-55

Author(s):

Grady Koch ◽

Elias Koch

Keyword(s):

Vertical Axis ◽

Vertical Axis Turbine

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Unsteady Aerodynamic Forces Measured on a Fluttering Profile

Volume 4: Fluid-Structure Interaction ◽

10.1115/pvp2014-28567 ◽

2014 ◽

Author(s):

Igor Zolotarev ◽

Václav Vlček ◽

Jan Kozánek

Keyword(s):

Mach Number ◽

Flow Field ◽

Degrees Of Freedom ◽

Air Flow ◽

Optical Measurements ◽

Energy Contribution ◽

Aerodynamic Forces ◽

Unsteady Aerodynamic ◽

New Information ◽

Drag And Lift

The study presents evaluation of optical measurements of the air flow field near the fluttering profile NACA0015 with two-degrees of freedom, Mach number of the flutter occurrence were M=0.21 and M=0.45. Aerodynamic forces (drag and lift components) were evaluated independently on the upper and lower surfaces of the profile. Using the mentioned decomposition, the new information about mechanism of flutter properties was obtained. The forces on the upper and lower surfaces are phase shifted and are partially eliminated as a result of the circulation around the profile. The cycle changes of these forces cause the permanent energy contribution from the airflow to the vibrating system.

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Performance Modeling of Ducted Vertical Axis Turbine Using Computational Fluid Dynamics

Marine Technology Society Journal ◽

10.4031/mtsj.47.4.12 ◽

2013 ◽

Vol 47 (4) ◽

pp. 36-44 ◽

Cited By ~ 3

Author(s):

Prasun Chatterjee ◽

Raymond N. Laoulache

Keyword(s):

Performance Modeling ◽

Flow Direction ◽

Computational Cost ◽

Vertical Axis ◽

Area Ratio ◽

Diameter Ratio ◽

Turbulent Model ◽

Ansys Fluent ◽

Second Order In Time ◽

Vertical Axis Turbine

AbstractVertical axis turbines (VATs) excel over horizontal axis turbines in their independent flow direction. VATs that operate in an enclosure, e.g., a diffuser shroud, are reported to generate more power than unducted VATs. A diffuser-shrouded, high solidity of 36.67%, three-blade VAT with NACA 633-018 airfoil section is modeled in 2-D using the commercial software ANSYS-FLUENT®. Incompressible, unsteady, segregated, implicit, and second order in time and space solver is implemented in association with the Spalart-Allmaras turbulent model with a reasonable computational cost. The computational results are assessed against experimental data for unducted VAT at low tip speed ratios between 1 and 2 for further numerical analysis on diffuser models. Different diffuser designs are investigated using suitable nozzle size, area ratio, length-to-diameter ratio and angles between the diffuser inner surfaces. The numerical model shows that, for a specific diffuser design, the ducted VAT performance coefficient can be augmented by almost 90% over its unducted counterpart.

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