A111 On design and evaluation of performances of prototype Mg-alloy micro vertical axis wind turbine

2015

JFST

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In this research, an inexpensive aerodynamic shape optimization of airfoil is performed for Darrieus type vertical axis wind turbine (VAWT). Computational fluid dynamics (CFD) evaluations of various airfoil shapes are treated inexpensively by considering the apparent flow velocity magnitudes and apparent angles of attack at multiple positions of VAWT airfoil, which includes some assumptions as two dimensional steady flows and no consideration about flow interactions between blade airfoils. Global optimal shapes are efficiently explored by using a Kriging response surface model approach. An optimal VAWT airfoil is obtained by the maximization of a proposed objective function. Since our objective function for this design optimization of VAWT airfoil can be primary decomposed into the terms of thrust force and pitching moment, another multi-objective optimization of thrust/pitching moment coefficients is also performed for detailed discussions about the obtained optimal airfoil. Analysis of variance is performed on the Kriging response surface model to extract design knowledge in this design optimization problem. The obtained optimal airfoil achieves a significant improvement in the aerodynamic performance compared with an existing airfoil. Finally, expensive unsteady CFD simulations are performed for the obtained airfoils, that take into account unsteady flow interactions between three blade airfoils. The results of the unsteady CFD simulations validate the effectiveness of the proposed aerodynamic shape optimization approach for VAWT airfoil.

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Section: Cfd Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Inexpensive airfoil shape optimization for vertical axis wind turbine and its validation

2015

JFST

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“…Since the turbulent intensity of natural wind is generally 10-20%, we assume fully turbulent flows in this study, and then the Spalart-Allmaras one equation turbulence model is utilized in this computation [8]. The computational grid topology utilized in this study is O-type, whose total number of grid points is about 30,000.…”

Section: B Cfd Methodsmentioning

confidence: 99%

“…The latter has attracted much more attention in recent years, whose axis of rotation is perpendicular to the main flow. Many experimental/numerical investigations have been performed in the literature [1][2][3][4][5][6][7][8]. The VAWT has an advantage over the HAWT in the flexibility about the direction of the main flow.…”

Section: Introductionmentioning

confidence: 99%

Efficient Aerodynamic Shape Optimization of VAWT Airfoil and Its Validation

33rd Wind Energy Symposium

2015

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In this paper, an efficient aerodynamic shape optimization of VAWT airfoil is performed with a Kriging response surface model approach. Numerical evaluations of various airfoil shapes are treated inexpensively by considering the apparent flow velocity magnitudes and apparent angles of attack at multiple positions of VAWT airfoil, which includes some assumptions as two dimensional steady flows, no consideration about flow interactions between blade airfoils and so on. An optimal VAWT airfoil is obtained by the minimization of a proposed objective function. Since our objective function for this design optimization of VAWT airfoil can be primary decomposed into the terms of thrust force and pitching moment, another multi-objective optimization of thrust/pitching moment coefficients is also performed for detailed discussions about the obtained optimal airfoil. The obtained optimal airfoil achieves a significant improvement in the aerodynamic performance compared with an existing airfoil. ANOVA analysis is also performed on the Kriging model to extract more engineering design information of the VAWT airfoil. Finally, expensive unsteady CFD simulations are performed for the obtained airfoils, that take into account unsteady flow interactions between three blade airfoils. The results of the unsteady CFD simulations validate the effectiveness of the proposed aerodynamic shape optimization approach of VAWT airfoil.

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Numerical / Experimental Investigation of Airfoil Shape for Small VAWT

34th Wind Energy Symposium

2016