Performance analysis of a Darrieus-type wind turbine for a series of 4-digit NACA airfoils

Abstract

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.

Design of Vertical Axis Wind Turbine Darrieus Type (H- Darrieus Rotor) of 0.20 KW from the Software Topsolid

“…The aerodynamic parameters obtained for the NACA 0015 profile (lift, drag, angle of attack, stall angle, etc.) were compared with the values observed in some works taken from the literature such as those of Rogowski et al [18], Boumrar [34] and dealing with the same profile. The results show that the stall obtained by Rogowski et al [18] is light and does not suffer from a sudden drop in aerodynamic profiles, contrary to the lift profile observed in this study, where the stall is somewhat abrupt.…”

“…The choice of the aerodynamic profile is most often made using numerical fluid dynamics methods and less often using experimental tests [25,26]. Many authors have studied the aerodynamic performance of VAWTs equipped with a specific type of airfoil, usually the NACA 00XX [18]. This is the case of Mohamed et al [27] using many types of symmetrical and asymmetrical airfoils, who have shown that the symmetrical NACA 0015 airfoil has a high aerodynamic efficiency that is as high as the best among the tested airfoils.…”

“…It is also used to identify the curves that will be used to determine the lift and drag coefficients as well as the angles of attack and stall. It is expressed as follows [18,31]:…”

“…As with velocity characteristic value is used to have a single dimensionless parameter for an operating condition, which is compared to the sound speed and noted a. Its expression is given by equation (18). Its value is usually very low in the context of small win turbines, in the range of 10…”

“…Several field tests are proposed to validate the automatic start, low noise and stable performance of the new rotary wing design. Rogowski et al [18] estimated the aerodynamic performance of the H-Darrieus turbine, the aerodynamic loads on the blades and the downstream speed profiles behind the rotor. The wind turbine model is based on the rotor designed by McDonnell Aircraft Company.…”