Channels, Fall 2020

Channels • 2 020 • Volume 5 • Number 1 Page 9 Fig. 9 Velocity (m/s) separation from surface of 2D circular (a) smooth cylinder (b) Model A and (b) Model B Song [10] suggested that turbulence in the grooves could act as a sort of “bearing” for the air to roll over the cylinder surface. Fig. 10 shows turbulence induced in the grooves, similar to what Song [10] found in his study. In Fig. 10b, Model B is shown to have turbulence developing early on in the grooves and seen in Table IV, Model B showed the greatest drag reduction. The two-dimensional circular cylinder study showed expected trends as the turbulence found in the grooves corresponded to a lower angle of detachment and thus a smaller wake region behind the cylinder. The driving cause of this drag reduction seems to pertain to the existence of turbulence in the grooves. Fig. 10 Turbulent kinetic energy (J/kg) contours for 2D circular (a) Model A and (b) Model B Two-dimensional CFD was performed on both smooth elliptical cylinder and Model