Numerical Studies on the Effect of Cambered Airfoil Blades on Self-Starting of Vertical Axis Wind Turbine Part 1: NACA 0012 and NACA 4415

Abstract

This is Part-1 of the two-part paper in considering the effect of cambered airfoil blades on self-starting of vertical axis wind turbine. Part 1 reports the numerical studies on self-starting of vertical axis wind turbine with comparative studies involving NACA 0012 and cambered airfoil NACA 4415. Part 2 of the paper deals with numerical studies of NACA 0018 and cambered air foil NACA 63415. Darrieus type VAWT is attracting many researchers attention for its inherent advantages and its diversified applications. However, a disadvantage is when the rotor is stationary, no net rotational forces arises, even at high-wind speed. The principal advantage of the vertical axis format is their ability to accept wind from any direction without yawing mechanism. However, self-starting capability is the major drawbacks. Moreover, literatures based on computational analysis involving the cambered airfoil are few only. The objective of this present study is to select the suitable airfoil blades on self-starting of VAWT at low-Reynolds number. The numerical studies are carried out to identify self-starting capability of the airfoil using CFD analysis by studying the flow field over the vertical axis wind turbine blades. The commercial CFD code, ANSYS CFX 13.0© was used for the present studies. Initially, the flow over NACA 0012 was simulated and analyzed for different angles of attacks and similarly carried out for NACA 4415. The contours of static pressure distribution and velocity as well as the force and torque were obtained. Even though the lift force for cambered airfoil NACA 4415 is higher, based on the torque values of the above blade profiles, asymmetrical airfoil NACA 0012 is found to be appropriate for self-starring of VAWT.

Structural performance of composite tidal turbine blades

“…In addition, due to the circular plane in which the tidal turbine blade operates a high lift coefficient at high angles of attack is critical [32], but a range of high lift coefficients have negative impact on the efficiency and power generation [32,33]. To this end, the NACA 4415 family of aerofoils [34][35][36] were chosen here as they offer high lift-to-drag ratios over a wide range of angle of attack, combined with a reasonably thick cross section to improve structural properties. The lift-to-drag ratio, lift coefficient and angle of attack from the NACA 4415 aerofoil were used as inputs to the BEMT model in the MATLAB code.…”

Numerical Studies on the Effect of Cambered Airfoil Blades on Self-Starting of Vertical Axis Wind Turbine Part 2: NACA 0018 and NACA 63415

“…The objective of this present study is to select the suitable airfoil blades on self starting of VAWT at low-Reynolds number. NACA 0012 and NACA 4415 were discussed in Part 1 of this paper [6] to study the capabilities of the airfoil blades by considering the effect of cambered airfoil blades on self-starting of VAWT. The background of the problem taken up for the present numerical studies is dealt in detail in Part 1 of this paper [6].…”

“…The commercial CFD code, ANSYS CFX 13.0 © is used for the present numerical studies. The numerical validation and computational methodologies deployed for the present numerical investigations are discussed in detail in Part 1 of this paper [6]. The details about this are not shown in this paper for the sake of brevity.…”

Evaluating the effect of unsteady air flow on a slotted aerofoil of wind turbines

“…So, the NACA 4415 aerofoil could be used for several wind applications. M. Premkumar et al [7] studied numerically the cambered aerofoil blade a vertical axis wind turbine blades. The self-starting of the symmetrical NACA 0012 and cambered NACA 4415 blades were studied at various angles of attack.…”