Numerical Simulation of the Aerodynamic Performance of a H-Type Wind Turbine during Self-Starting

2014 ◽  
Vol 529 ◽  
pp. 296-302 ◽  
Author(s):  
Wei Zuo ◽  
Shun Kang

The aerodynamic performance and the bypass flow field of a vertical axis wind turbine under self-starting are investigated using CFD simulations in this paper. The influence of pitch angle variations on the performance of the wind turbine during self-starting is presented. A two-dimensional model of the wind turbine with three blades is employed. A commercial software FlowVision is employed in this paper, which uses dynamic Cartesian grid. The SST turbulence model is used for turbulence modeling, which assumes the flow full turbulent. Based on the comparison between the computed time-dependent variations of the rotation speed with the experimental data, the time-dependent variations of the torque are presented. The characteristics of self-starting of the wind turbine are analyzed with the pitch angle of 0o、-2oand 2o. The influence of pitch angle variations on two-dimensional unsteady viscous flow field through velocity contours is discussed in detail.

Author(s):  
Akiyoshi Iida ◽  
Akisato Mizuno ◽  
Kyoji Kamemoto

Unsteady flow field and flow induced noise of vertical axis wind turbine are numerically investigated. The flow field is numerically calculated by the vortex method with core-spreading model. This simulation obtains aerodynamic performance and aerodynamic forces. Aerodynamic noise is also simulated by using Ffowcs Williams-Hawkings equation with compact body and low-Mach number assumptions. Tip speed of rotor blades are not so high, then the contribution of the moving sound source is smaller than that of the dipole sound source. Since the maximum power coefficient of VAWT can be obtained at lower tip-speed ratio compared to the conventional, horizontal axis wind turbines, the aerodynamic noise from vertical axis wind turbine is smaller than that of the conventional wind turbines at the same aerodynamic performance. This result indicates that the vertical axis wind turbines are useful to develop low-noise wind turbines.


Author(s):  
Teresa Parra-Santos ◽  
Diego J. Palomar Trullen ◽  
Armando Gallegos ◽  
Cristobal N. Uzarraga ◽  
Maria Regidor-Sanchez ◽  
...  

The performance of a Vertical Axis Wind Turbine (VAWT) is numerically analyzed. Influence of fixed pitch angle is studied to get tendencies on the characteristic curves. The set up corresponds with an H-Darrieus with three straight NACA airfoils attached to a vertical shaft. Two-dimensional, transient, Navier Stokes equations are solved with a Third-Order Muscl scheme using SIMPLE to couple pressure and velocity. At least three revolutions must be simulated to get the periodic behaviour. Transition SST turbulence model has been chosen based on literature. Pitch angles of −6° and −10° have been analyzed with Tip Speed Ratios ranging from 0.7 and 1.6. The pitch angle of −10° improves the performance of the wind turbine. Instantaneous and averaged power coefficients as well as detailed flow field around the airfoils are shown.


2019 ◽  
Author(s):  
Krzysztof Rogowski ◽  
Martin Otto Laver Hansen ◽  
Galih Bangga

Abstract. The purpose of this paper is to estimate the H-Darrieus wind turbine aerodynamic performance, aerodynamic blade loads and velocity profiles downstream behind the rotor. The wind turbine model is based on the rotor designed by McDonnell Aircraft Company. The model proposed here consists of three fixed straight blades; in the future this model is planned to be develop with controlled blades. The study was conducted using the unsteady Reynolds averaged Navier-Stokes (URANS) approach with the k-ω shear stress transport (SST) turbulence model. The numerical two-dimensional model was verified using two other independent aerodynamic approaches: the vortex model developed in Technical University of Denmark (DTU) and the extended version of the CFD code FLOWer at the University of Stuttgart (USTUTT). All utilized numerical codes gave similar result of the instantaneous aerodynamic blade loads. In addition, steady-state calculations for the applied airfoils were also made using the same numerical model as for the vertical axis wind turbine (VAWT) to obtain lift and drag coefficients. The obtained values of lift and drag force coefficients, for a Reynolds number of 2.9 million, agree with the predictions of the experiment and XFoil over a wide range of angle of attack. The maximum rotor power coefficients are obtained at 0.5, which makes this impeller attractive from the point of view of further research. This work also addresses the issue of determining the aerodynamic performance of the rotor with various 4-digit NACA airfoils. The effect of two airfoil parameters, maximum airfoil thickness and maximum camber, on aerodynamic rotor performance is investigated. Research has shown that if this rotor were to work with fixed blades it is recommended to use the NACA 1418 airfoil instead of the original NACA 0018.


1995 ◽  
Vol 117 (3) ◽  
pp. 187-193 ◽  
Author(s):  
B. Fortunato ◽  
A. Dadone ◽  
V. Trifoni

An accurate two-dimensional methodology, the COIN Lambda Fast Solver, for the computation of the flow field about a vertical axis wind turbine is presented. Such a technique determines the smooth flow field by integrating the compatibility conditions along the bicharacteristic lines. The time-averaged wind turbine effects are introduced by means of an actuator porous cylinder having the same radius of the wind turbine. A time-averaged flow field is determined. The computed vertical axis wind turbine performances are compared with other numerical results. A qualitative comparison with experimental data is also shown. Such comparisons prove the merits of the proposed methodology.


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