Design of Passive Flow Control Device Derived from Bird Wing Aerodynamics.
separation is a constant problem in airfoil applications ranging from airplane wings to
turbine blades. Active solutions such as pulsed blowing require more energy and
complexity while passive solutions such as vortex generators often come at a cost of
increased drag. Bird wings have a unique solution to the problem that involves the
covert feathers on the top of their wings. ... read moreThe feathers pop up under separated
conditions and create two small circulations zones that increase lift and decreases
drag. In this thesis, an airfoil is designed and fabricated along with feather-like
flaps that are attached to the surface of the wing. Particle image velocimetry (PIV)
testing is used to verify the flap's effect on the flow field and show enhanced
streamline curvature in the separated region. A three-component strain gage force
transducer is designed and fabricated to measure lift, drag, and pitching moment on the
wing. Experimental results show an increase in lift by up to 6.4%, decrease in drag by
as much as 13.2%, and decrease in pitching moment by 8.3% by adding a flap to the bare
wing. Finally, three-dimensional effects are investigated by testing flaps with a
different number of span-wise divisions.
Thesis (M.S.)--Tufts University, 2012.
Submitted to the Dept. of Mechanical Engineering.
Advisor: Chris Rogers.
Committee: Marc Hodes, and Rich Wlezien.
Keywords: Mechanical engineering, and Aerospace engineering.read less