Theoretical and computational studies on the optimal positions of NACA airfoils used in horizontal axis wind turbine blades

Abstract

This paper presents a theoretical and computational study to determine the optimal positions of airfoils along the length of the horizontal axis wind turbine blade. We used four and five-digit NACA airfoils to model a 54-meter blade. The lift, drag coefficient, and lift-to-drag ratio of each airfoil are determined by using QBlade software. The aerodynamic performance of the airfoils is studied based on the blade element momentum theory, and Matlab software is used for numerical implementation. The velocity and pressure distributions on each airfoil are assessed using computational fluid dynamics. We implement the thickness distribution techniques to adjust the positions of the airfoils along the length of the blade. It is noted that stresses reach their maximum values at the root and minimum at the tip section. Thus, the thicker (NACA 4420) and thinner (NACA 23012) airfoils are set at 20% of the maximum chord and 91.11% at the tip sections of the blades. The remaining sections of the blade are configured using linear interpolation methods. Specifically, the maximum chord length of the new design is reduced by 18.06% compared to the NACA 23012 rotor blade. Finally, the recommended tip speed ratio for the designed rotor blade is estimated using the graphs of the normal and tangential forces, thereby producing a safe and efficient design.

NACA0009 ve NACA4415 Kanat Profillerinin Sayısal ve İstatistiksel Aerodinamik Performans Analizi

“…These results were also found in another study [25]. Both studies [24,25] support the data obtained in the presented study. In addition, NACA4415 airfoil type can achieve higher lift coefficient than NACA0009.…”

“…This study [23] confirms the data obtained for NACA0009 airfoil in present study. In a study, NACA4415 lift and drag coefficients were calculated at various angles of attack and they found that the increase for the angle of attack from 0 degrees to 8 degrees increased the lift and drag coefficients [24]. These results were also found in another study [25].…”

“…In a study, NACA4415 CL and CD were calculated in accordance with various angles of attack and they found that the increase of the angle of attack up to 8 degrees increased the lift and drag coefficients. They also observed the effect of Reynold Numbers on the aerodynamic performance of airfoils [24]. CL and CD of the NACA4412 Airfoil were investigated depending on the various angles of attack and Reynold Numbers.…”

“…In CFD calculations, realizable k-epsilon was used as turbulence model. This model was used in many studies[4,21,24,26,30]. The transport equations in accordance with k and ∈ based on the realizable k-∈ model are[31]:…”