Numerical Analysis on The Effects of Stagger, Thickness, and Curvature on The Propulsion of Tandem Airfoil

The study of the aerodynamics of flapping airfoils is crucial to understand the flight of natural flyers and its potential applications in developing micro air vehicles and wind/water turbine blades. There has been much research on the aerodynamics of flapping wings recently, but there is only a little research relating to the tandem airfoil. Therefore, this study is conducted to determine the aerodynamic characteristics of the tandem airfoil at Re = 100000, typical of insect flight. The tandem airfoil is plunging and pitching harmonically. This study numerically analyzes the effects of stagger, thickness, and curvature on tandem airfoil propulsion. The effects of stagger are studied using NACA 0012, while the effects of thickness are analyzed on NACA 0012, 0015, 0020 and 0030. The simulations to study the effects of curvature are conducted using NACA 0030. The optimum distance of the stagger is X/c = 2.5, but the propulsive efficiency of tandem NACA 0012 is still smaller than two single NACA 0012 airfoils. For the most optimum thickness at 30% of the chord length, the propulsive efficiency of tandem NACA 0030 is higher than two single NACA 0030 airfoils. Meanwhile, the most optimum curvature is 0% because the increase in curvature of the airfoil reduces propulsive efficiency.