Numerical study of effect of winglet planform and airfoil on a horizontal axis wind turbine performance

This article introduces novel blade tip geometric modification to improve the aerodynamic performance of horizontal-axis wind turbine by adding auxiliary cascading blades toward the tip region. This study focuses on the new turbine shape and how it enhances the turbine performance in comparison with the classical turbine. This study is performed numerically for National Renewable Energy Laboratory Phase II (non-optimized wind turbine) taking into consideration the effect of adding different cascade configurations on the turbine performance using ANSYS FLUENT program. The analysis of single-auxiliary and double-auxiliary cascade blades has shown an impact on increasing the turbine power of 28% and 76%, respectively, at 72 r/min and 12.85 m/s of wind speed. Knowing that the performance of cascaded wind turbine depends on the geometry, solidity and operating conditions of the original blade; therefore, these results are not authorized for other cases.

Download Full-text

The prediction of horizontal axis wind turbine performance in yawed flow using an unsteady prescribed wake model

Proceedings of the Institution of Mechanical Engineers Part A Journal of Power and Energy ◽

10.1243/0957650991537419 ◽

1999 ◽

Vol 213 (1) ◽

pp. 33-43 ◽

Cited By ~ 35

Author(s):

F. N. Coton ◽

T Wang

Keyword(s):

Wind Turbine ◽

Horizontal Axis ◽

Horizontal Axis Wind Turbine ◽

Turbine Performance ◽

Wake Model

Download Full-text

Numerical Study of Superharmonic Resonances in a Mistuned Horizontal-Axis Wind-Turbine Blade-Rotor Set

Volume 8: 31st Conference on Mechanical Vibration and Noise ◽

10.1115/detc2019-98010 ◽

2019 ◽

Author(s):

Ayse Sapmaz ◽

Gizem D. Acar ◽

Brian F. Feeny

Keyword(s):

Wind Turbine ◽

Initial Conditions ◽

Numerical Study ◽

Horizontal Axis ◽

Rotor Speed ◽

Horizontal Axis Wind Turbine ◽

First Order ◽

Direct Excitation ◽

Rotor Angle ◽

Perturbation Solutions

Abstract This paper is on a simplified model of an in-plane blade-hub dynamics of a horizontal-axis wind turbine with a mistuned blade. The model has cyclic parametric and direct excitation due to gravity and aerodynamics. This work follows up a previous perturbation study applied to the blade equations written in the rotor-angle domain and decoupled from the hub, in which superharmonic and primary resonances were analyzed. In this work, the effects of mistuning, damping, and forcing level are illustrated. The first-order perturbation solutions are verified with comparisons to numerical simulations at superharmonic resonance of order two. Additionally, the effect of rotor loading on the rotor speed and blade amplitudes is investigated for different initial conditions and mistuning cases.

Download Full-text

A Simplified Free Wake Method for Horizontal-Axis Wind Turbine Performance Prediction

Journal of Fluids Engineering ◽

10.1115/1.3242595 ◽

1986 ◽

Vol 108 (4) ◽

pp. 400-406 ◽

Cited By ~ 21

Author(s):

A. A. Afjeh ◽

T. G. Keith

Keyword(s):

Wind Turbine ◽

Performance Prediction ◽

Vortex Method ◽

Computational Effort ◽

Horizontal Axis ◽

Tip Vortex ◽

Performance Parameters ◽

Horizontal Axis Wind Turbine ◽

Turbine Performance ◽

Free Wake

Based on the assumption that wake geometry of a horizontal-axis wind turbine closely resembles that of a hovering helicopter, a method is presented for predicting the performance of a horizontal-axis wind turbine. A vortex method is used in which the wake is composed of an intense tip-vortex and a diffused inboard wake. Performance parameters are calculated by application of the Biot-Savart law along with the Kutta-Joukowski theorem. Predictions are shown to compare favorably with values from a more complicated full free wake analysis and with existing experimental data, but require more computational effort than an existing fast free wake method.

Download Full-text

A comparative numerical study of four turbulence models for the prediction of horizontal axis wind turbine flow

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1243/09544062jmes1901 ◽

2010 ◽

Vol 224 (9) ◽

pp. 1973-1979 ◽

Cited By ~ 19

Author(s):

N S Tachos ◽

A E Filios ◽

D P Margaris

Keyword(s):

Wind Turbine ◽

Turbulence Model ◽

Numerical Study ◽

Free Field ◽

Turbulence Models ◽

Horizontal Axis ◽

Wind Condition ◽

Computational Domain ◽

Horizontal Axis Wind Turbine ◽

Rans Equations

The analysis of the near and far flow fields of an experimental National Renewable Energy Laboratory (NREL) rotor, which has been used as the reference rotor for the Viscous and Aeroelastic Effects on Wind Turbine Blades (VISCEL) research program of the European Union, is described. The horizontal axis wind turbine (HAWT) flow is obtained by solving the steady-state Reynolds-averaged Navier—Stokes (RANS) equations, which are combined with one of four turbulence models (Spalart—Allmaras, k—∊, k—∊ renormalization group, and k—ω shear stress transport (SST)) aiming at validation of these models through a comparison of the predictions and the free field experimental measurements for the selected rotor. The computational domain is composed of 4.2×106 cells merged in a structured way, taking care of refinement of the grid near the rotor blade in order to enclose the boundary layer approach. The constant wind condition 7.2 m/s, which is the velocity of the selected experimental data, is considered in all calculations, and only the turbulence model is altered. It is confirmed that it is possible to analyse a HAWT rotor flow field with the RANS equations and that there is good agreement with experimental results, especially when they are combined with the k—ω SST turbulence model.

Download Full-text

Quantitative impact of a micro-cylinder as a passive flow control on a horizontal axis wind turbine performance

Energy ◽

10.1016/j.energy.2021.122654 ◽

2021 ◽

pp. 122654

Author(s):

Wafaa Mostafa ◽

Abouelmagd Abdelsamie ◽

Momtaz Sedrak ◽

Dominique Thévenin ◽

Mohamed H. Mohamed

Keyword(s):

Flow Control ◽

Wind Turbine ◽

Horizontal Axis ◽

Horizontal Axis Wind Turbine ◽

Passive Flow Control ◽

Passive Flow ◽

Turbine Performance ◽

Quantitative Impact

Download Full-text

Analysis of a small horizontal axis wind turbine performance

International Journal of Energy Research ◽

10.1002/er.699 ◽

2001 ◽

Vol 25 (6) ◽

pp. 501-506 ◽

Cited By ~ 5

Author(s):

Ahmet Z. Sahin ◽

Ahmed Z. Al-Garni ◽

Abdulghani Al-Farayedhi

Keyword(s):

Wind Turbine ◽

Horizontal Axis ◽

Horizontal Axis Wind Turbine ◽

Turbine Performance

Download Full-text

EFFECTIVENESS OF BLADE TIP ON LOW SPEED HORIZONTAL AXIS WIND TURBINE PERFORMANCE

Jurnal Teknologi ◽

10.11113/jt.v78.9582 ◽

2016 ◽

Vol 78 (8-4) ◽

Author(s):

Muhammad Hafidz Ariffudin ◽

Fazila Mohd Zawawi ◽

Haslinda Mohamed Kamar ◽

Nazri Kamsah

Keyword(s):

Wind Turbine ◽

High Efficiency ◽

Turbine Blades ◽

Horizontal Axis ◽

Tip Vortex ◽

Wind Turbine Blades ◽

Horizontal Axis Wind Turbine ◽

Low Speed ◽

Low Wind Speed ◽

Turbine Performance

There has been an increasing demand for renewable energy in order to create a sustainable society as the non-renewable energies such as fossil fuel resources are limited. Modern wind turbines claim that they have a high efficiency in term of wind energy extraction. However, there are still having losses due to tip vortex causing to a reduction in performance. Motivated by this reason, this research aims at exploring the possibility to increase the performance of low speed small-scaled horizontal axis wind turbine with various tip devices using Computational Fluid Dynamics (CFD). Four wind turbine blades with different tip devices which consist of sword tip, swept tip, upwind winglet and downwind winglet are compared with wind turbine blade without tip device in term of CP. The application of tip device can significantly reduce induced tip vortex and improve wind turbine performance. For TSR below than 4, adding a sword tip increases CP about 7.3%, swept tip increases CP about 9.1%, upwind winglet increases CP about 1.8% and downwind winglet increases CP about 3.2%. It is observed that the best tip device for low wind speed application is swept tip as it give the highest performance increment compared to without tip device.

Download Full-text