Effect of moving surfaces on the airfoil boundary-layer control

Unrestrained Cylinders Rolling in Steady Uniform Flows

“…The exact speed at which separation is completely suppressed was not determined, but the numerical results showed that even at terminal velocity ratio n = 0.6, the flow was not separating from the cylinder. The results verified expectations that separation would be suppressed based on the early work reported by Prandtl and Tietjens (1957) and Goldstein (1965), and the more recent work reported by Modi et al (1990Modi et al ( , 1991aModi et al ( , 1991b and Munshi et al (1996).…”

“…When the cylinder was rotated, separation was eliminated around the corner of the block. In more recent studies, Modi et al (1990Modi et al ( , 1991b showed how rotating cylinders at certain points along an airfoil controlled separation and resulted in increased lift and stall angles for the foil. Modi et al (1991a) investigated the flow past bluff bodies.…”

Numerical study of blowing and suction slot geometry optimization on NACA 0012 airfoil

“…The values of lift and drag coefficients are presented in Table 6, which indicates that the results for two slot geome-try types are strongly closed, whereas the vortexes passing the airfoil are different. The slot geometry of type 1 models the moving surface (wall motion) over the airfoils [40,41] rather than the tangential blowing. Blowing is defined as a method of preventing separation to supply additional energy to the particles of fluid being retarded in the boundary layer [3].…”

Effect of Gap between Airfoil and Embedded Rotating Cylinder on the Airfoil Aerodynamic Performance

“…Modi [1] carried out tests on rotating cylinders located at the leading and trailing edge of the airfoil. The leading edge rotating cylinder extended the lift curve without affecting its slope thus increasing the maximum lift and delaying stall.…”