Pitching Airfoil with Combined Gurney Flap and Unsteady Trailing-Edge Flap Deflection

b = semispan c = airfoil chord Cl = lift coefficient Cm = pitching moment coefficient Cp = surface pressure coefficient f = oscillation frequency h = Gurney flap height td = flap actuation duration ts = flap actuation start time u1 = freestream velocity = angle of attack ds = dynamic-stall angle f = final angle i = initial angle ss = static stall angle = f i, pitch amplitude t = total airfoil pitch time max = maximum flap deflection = fc=u1, reduced frequency