Numerical Analysis of Horizontal-Axis Wind Turbine Characteristics in Yawed Conditions

Abstract

Computational fluid dynamics (CFD) modeling and experiments have both advantages and disadvantages. Doing both can be complementary, and we can expect more effective understanding of the phenomenon. It is useful to utilize CFD as an efficient tool for the turbomachinery and can complement uncertain experimental results. However the CFD simulation takes a long time for a design in generally. It is need to reduce the calculation time for many design condi- tions. In this paper, it is attempted to obtain the more accurate characteristics of a wind turbine in yawed flow condi- tions for a short time, using a few grid points. It is discussed for the reliability of the experimental results and the CFD results.

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Suzuki, M. (2012) Numerical Analysis of Horizontal-Axis Wind Turbine Characteristics in Yawed Conditions. Open Journal of Fluid Dynamics, 2, 331-336. doi: 10.4236/ojfd.2012.24A041.

1. Introduction

Computational fluid dynamics (CFD) modeling and experiments have both advantages and disadvantages. Doing both can be complementary, and we can expect more effective understanding of the phenomenon. Although CFD has more advantages than experiments for the prediction where experiments are difficult to carry out, generally when compared with experimental results, it is difficult to obtain reliable results for a large domain by using CFD. However, it is possible to obtain useful CFD results based on verification by the experimental results. Moreover, experiments cannot deliver correct results for any arbitrary condition due to limitations to experimental equipment, measurement errors and problems with measurement systems. It is useful to utilize CFD as an efficient tool for the turbomachinery and can complement uncertain experimental results. However the CFD simulation takes a long calculation time for a design in generally. It is need to reduce the calculation time for many design conditions. In this paper, it is attempted to solve the more accurate characteristics of a wind turbine for a short time even a personal computer, using coarse grid [1]. In this paper the wind turbine characteristics of the yawed condition are discussed including the reliability of the experimental results and the CFD results.

2. Numerical Method

The in-house code used is an incompressible finite volume Navier-Stokes solver which is developed originally. The solver is based on structured grids and the use of curve-linear boundary fitted coordinates. The grid arrangement is collocated (Perić et al. [2]) and the Rhie and Chow interpolation method [3] is used. The SIMPLE algorithm (Patankar [4]) is used for pressure-velocity coupling. The convection term is calculated using the QUICK scheme (Leonard [5]) and the other terms in space are calculated using the 2nd order difference schemes. It is well known that sophisticated turbulence models do not always produce better results than the very simple models. For practical applications that are computationally expensive it is often wiser to use a simple approach. Therefore the proven and computationally efficient Launder-Sharma low-Reynolds-number k-e turbulence model [6] is used in this report.

3. Wind Turbine and Aerodynamic Force Acting to Blade

Figure 1 shows a schematic view of experimental apparatus for a wind turbine carried out by Vermeer [7]. A two bladed wind turbine is situated in front of the wind turbine. The wind turbine has diameter of 1.2 m and the blades consist of NACA 0012 airfoil and the chord length of 0.08 m. The experiment is conducted at wind velocity of 5 m/s, and the measured data are the wind velocity, the number of rotation, the torque, and the thrust. Moreover, Haans et al. [8,9] measure with the same experiment equipment about the thrust according to a yawed wind (0˚, ±15˚, ±30˚, ±45˚) of 5.5 m/s in speed

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1] M. Suzuki, “Evaluation of Experimental Results for Wind Turbine Characteristics by CFD,” Proceedings of the 9th International Symposium on Experimental and Computational Aero-thermodynamics of Internal Flows (ISAIF9), Gyeongju, 2009, Paper No. 1D-2.
[2] M. Peri?, R. Kessier, and G. Scheuerer, “Comparison of Finite-Volume Numerical Methods with Staggered and Collocated Grids,” Computers & Fluids, Vol. 16, No. 4, 1988, pp. 389-403. doi:10.1016/0045-7930(88)90024-2
[3] C. M. Rhie and W. L. Chow, “Numerical Study of the Turbulent Flow Past an Airfoil with Trailing Edge Separation,” AIAA Journal, Vol. 21, No. 11, 1983, pp. 15251532. doi:10.2514/3.8284
[4] S. V. Patankar, “Numerical Heat Transfer and Fluid Flow,” McGraw-Hill, New York, 1980.
[5] B. P. Leonard, “A Stable and Accurate Convective Modeling Procedure Based on Quadratic Upstream Interpolation,” Computer Methods in Applied Mechanics and Engineering, Vol. 19, No. 1, 1979, pp. 59-98. doi:10.1016/0045-7825(79)90034-3
[6] B. E. Launder and B. I. Sharma, “Application of the Energy-Dissipation Model of Turbulence to the Calculation of Flow near a Spinning Disk,” Letters in Heat Mass Transfer, Vol. 1, 1974, pp. 131-138. doi:10.1016/0094-4548(74)90150-7
[7] N. J. Vermeer, “Performance measurements on a Rotor Model with Mie-Vanes in the Delft Open Jet Tunnel,” Institute for Wind Energy, Delft University of Technology, Delft, 1991, IW-91048R.
[8] W. Haans, T. Sant, G. van Kuik and G. van Bussel, “Measurement of Tip Vortex Paths in the Wake of a HAWT Under Yawed Flow Conditions,” Journal of Solar Energy Engineering, Vol. 127, No. 4, 2005, pp. 456-463. doi:10.1115/1.2037092
[9] W. Haans, T. Sant, G. van Kuik and G. van Bussel, “Stall in Yawed Flow Conditions: A Correlation of Blade Element Momentum Predictions with Experiments,” Journal of Solar Energy Engineering, Vol. 128, No. 4, 2006, pp. 472-480. doi:10.1115/1.2349545
[10] L. E. Eriksson, “Generation of Boundary Conforming Grids around Wing-Body Configurations Using Transfinite Interpolations,” AIAA Journal, Vol. 20, No. 10, 1982, pp. 1313-1320. doi:10.2514/3.7980
[11] T. Maeda, Y. Kamada, J. Suzuki and H. Fujioka, “Rotor Blade Sectional Performance under Yawed Inflow Conditions,” Journal of Solar Energy Engineering, Vol. 130, No. 3, 2008, Article ID: 031018. doi:10.1115/1.2931514

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