Circulation Control Airfoil Study: Progress Report No. 4
Schmidt, Louis Vincent
MetadataShow full item record
The prime goal of the investigations has been the evaluation of the unsteady aerodynamics, and in particular the transfer functions, applicable to the Circulation Control Airfoil (CCA) for the situation of harmonic blowing perturbations superimposed upon a mean cavity pressure. Circulation control was achieved upon the relatively thick (t/c = 0.214) elliptically shaped two-dimensional air foil by tangential jet injection at an upper surface slot just ahead of the rounded trailing edge. The experiments were conducted in the Naval Postgraduate School unsteady flow 2 x 2 foot wind tunnel. Preliminary results were obtained disclosing the nature of unsteady surface pressures over the airfoil, both amplitude and phase, relative to the oscillating cavity pressures for a range of reduced frequencies, k=0 to 0.46, at a model attitude approximating the zero lift condition (blowing-off) at a moderate value of momentum blowing coefficient. Positive results were obtained towards identifying the behavior of the Coanda sheet dynamics, airfoil lift transfer function and airfoil damping moment
RightsThis publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.
NPS Report NumberNPS-67SX-77111
Showing items related by title, author, creator and subject.
Chandrasekhara, M.S.; Martin, P.B.; Tung, C. ;The control of compressible dynamic stall using a variable droop leading edge airfoil is described. The leading 25% of a VR-12 airfoil is drooped as it executes sinusoidal pitch oscillations such that the leading portion ...
Brawley, Stephen C. (Monterey, California. Naval Postgraduate School, 1993);An airfoil design technique has been developed which decreases the computational processing time by more than an order of magnitude when optimizing aerodynamic performance. The practicality of airfoil design using parallel ...
Sahin, Mehmet; Sankar, Lakshmi N.; Chandrasekhara, M.S.; Tung, Chee (American Institute of Aeronautics and Astronautics Inc., 2000);Dynamic stall calculations were carried out for an airfoil with a deformed leading edge shape at a freestream Mach number of 0.3. The surface deformations were done about a baseline NACA 0012 airfoil, effectively ...