Kelvin-Helmholtz Instability Due to Slot Blowing in Laminar Boundary Layers

Combined passive and active flow control for fixed-wing micro air vehicles

“…As less momentum is imparted to the flow in the foregoing case, a possible explanation for this behavior may lie in a more efficient manipulation of separated shear layer entrainment characteristics via excitation of Kelvin-Helmholtz instability. 39…”

“…As less momentum is imparted to the flow in the foregoing case, a possible explanation for this behavior may lie in a more efficient manipulation of separated shear layer entrainment characteristics via excitation of Kelvin-Helmholtz instability. 39 Facing a background of power constraints in MAV applications, as the AFC devices stand as major energy consumers, the amount of power required for their operation plays an important role in the design. Hence, as introduced earlier in this paper, the power coefficient C π is also a relevant parameter in the assessment of the AFC system.…”

“…Furthermore, a large actuator profile above the wing surface may inadvertently trip the flow, causing premature separation or an early transition to turbulent flow, thus increasing the skin friction drag. To circumvent these difficulties in MAV applications, micro-flow control devices, such as pneumatic turbulators, are of particular interest, 39,40 whereas several investigations have been carried out in other fields as well. These turbulators blow high-momentum air jets inside the boundary layer at stations where the boundary layer would be likely to separate.…”