Numerical investigation of aerodynamic characteristics of a slotted E387 airfoil

In the study, the three-dimensional flow past E387 airfoil with and without slot (plain) was studied numerically. To this end, student version of a commercial computational fluid dynamics (CFD) package program, Ansys Fluent (Ansys 2021 R1 Academic), was used. Both steady and unsteady simulations were performed. The aim of the study is to reveal the effect of using a passive flow control method (i.e. slot) on the aerodynamic characteristics (drag coefficient, lift coefficient, pitching moment) of a low Reynolds number airfoil. The numerical study was performed at a Reynolds number of 200000 based on the chord of the airfoil. Only one slot geometry designed was used. This results from a deficiency of computational sources and required software at Munzur University. The nondimensional distance between leading edge and the exit slot is a/c=0,005, the nondimensional distance between leading edge and the inlet slot is b/c=0,014, the angle of the inlet slot relative to the chordline is 15°, the angle of the outlet slot relative to the chordline is 90°, and the ratio of inlet slot width to outlet slot width is 1,56. Compared to the plain airfoil, airfoil with present slot is only capable of increasing time-averaged lift coefficient, , at angle of incidence of α=16°. The jet flow generated at the exit slot interacted with boundary layer developed on the upper surface. This caused that separated shear layers from the upper surface reattached to upper surface of the slotted airfoil. This results in a decrease in the static pressure on the upper surface and an increase in the . Overall, the airfoil with the current design slot is less effective in increasing the airfoil performance, /, compared to the plain airfoil.