Unsteady three-dimensional vortex sheet panel solutions for oscillating wings
by
John T. Conway
Agder College, Grooseveien 36, Grimstad, Norway
Coauthors: Fatih Tezok (TAI, Ankara, Turkey)

The paper will describe the application of the CANAERO-T (1,2,3) panel method to the problem of wings oscillating in pitch. The method has already been applied to impulsively started cases (3). CANAERO-T models inviscid unsteady flow around complex configurations using constant source panels on the configuration surface and bilinear doublet distributions on wake panels and on the camber surfaces of lifting components. Neumann boundary conditions are applied on the configuration surface and wake convection is used to compute the development with time of the wakes. Pressure distributions and forces are calculated from the unsteady Bernoulli equation, with the time derivative of the potential calculated using central differencing of the solutions for 3 consecutive time steps.

The method is able to capture the nonlinear self-interaction of the wake as it propagates downstream from the tailing edges of the lifting components, showing the "mushrooming" effect previously reported for two-dimensional calculations. The paper will examine cases at high and low reduced frequency for single wings and wing-body configurations. Phaze lags and hysteresis effects will also be explored.

REFERENCES (1) Conway, J. and Mackay, M., "Prediction of the effects of body separation vortices on submarine configurations using the CANAERO panel method", AIAA Paper 90-0302, 28th Aerospace Sciences Meeting, January 8-11 1990, Reno, Nevada.

(2) Mackay, M. and Conway, J., "Modelling the cross-flow body separation on a submarine using a panel method", Warship 91, RINA Symposioum on Naval Submarines, London, May 1991. (3) Conway, J. and Tezok, F., "A time-marching scheme for the CANAERO three-dimensional vortex sheets panel method", 38th Aerospace Sciences Meeting, January 10-13, 2000, Reno, Nevada.

Date received: January 3, 2000

Copyright © 2000 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # cadd-09.