Volume 11 Issue 1 ( March )

Inspired by insect flight, oscillatory motion with pitching and plunging has been studied, and tandem configurations have been explored to enhance propulsive efficiency. As a first step in analyzing an oscillating tandem airfoil configuration, tandem airfoils are modeled as stationary. The present study investigates the aerodynamic effects of pitching angles on a tandem airfoil system using two NACA airfoil profiles, NACA 0030 and NACA 4412. While numerical studies have examined wing profiles and pitching angles, experimental analyses are relatively scarce due to their cost and time intensiveness. This study aims to complement existing numerical data and provide new insights into the aerodynamic performance of tandem airfoils. Experimental investigations are conducted in a wind tunnel for pitching angle combinations of the front and rear airfoils of 5°-10°, 5°-15°, and 10°-15°. The findings indicate that increasing the pitching angle of the tandem foil oscillation system results in a higher drag coefficient (𝐶𝐶𝑑𝑑) and lift coefficient (𝐶𝐶𝑙𝑙). For the NACA 4412 profile, the maximum 𝐶𝐶𝑑𝑑 and 𝐶𝐶𝑙𝑙 values were obtained at a pitching angle of 10°- 15°, with 𝐶𝐶𝑑𝑑 = 1.553 and 𝐶𝐶𝑙𝑙 = 2.0565. The NACA 0030 profile exhibits a decreasing trend in 𝐶𝐶𝑑𝑑 with increasing pitching angle, reaching a maximum 𝐶𝐶𝑑𝑑 = 0.883 at 5°-10°, while 𝐶𝐶𝑙𝑙 increases with pitching angle, peaking at 𝐶𝐶𝑙𝑙 = 0.619.

Keywords: Oscillating Tandem Airfoil; Experimental analyses; Wind tunnel; NACA 0030; NACA 4412