TY - JOUR
T1 - The flow past a thin wing with an oscillating jet flap
JF - Philosophical Transactions of the Royal Society of London. Series A,
Mathematical and Physical Sciences
JO - Philos Trans R Soc Lond A
SP - 445
LP - 477
M3 - 10.1098/rsta.1965.0012
VL - 257
IS - 1085
AU -
Y1 - 1965/06/03
UR - http://rsta.royalsocietypublishing.org/content/257/1085/445.abstract
N2 - An exact solution is obtained for the linearized flow past a thin two-dimensional wing of chord c at zero incidence in an incompressible stream of density and undisturbed velocity U, with a thin jet of momentum-flux emerging from its trailing edge at an oscillating deflexion-angle exp.The motion is governed by a singular third-order integro-differential equation, which becomes tractable when μ is small: solutions in this 'weak-jet' limit depend on a single parameter v = and are found to exist only when . The possible significance of this critical frequency is discussed. Computations of jet shape and lift force for a range of values of v are presented, and the solutions for periodic plunging and pitching motions of the wing are derived from that for deflexion. The formulation follows that of an earlier paper (Spence 1961b), in which, however, an unsound approximation was made to the governing equations.
ER -