TY - JOUR
T1 - Geometrically-exact unsteady model for airfoils undergoing large amplitude maneuvers
AU - Yan, Zhimiao
AU - Taha, Haithem E.
AU - Hajj, Muhammad R.
N1 - Publisher Copyright:
© 2014 Elsevier Masson SAS. All rights reserved.
PY - 2014/12
Y1 - 2014/12
N2 - A semi-analytical, geometrically-exact, unsteady potential flow model is developed for airfoils undergoing large amplitude maneuvers. For this objective, the classical unsteady theory of Theodorsen is revisited relaxing some of the major assumptions such as (1) flat wake, (2) small angle of attack, (3) small disturbances to the mean flow components, and (4) time-invariant free-stream. The kinematics of the wake vortices is simulated numerically while the wake and bound circulation distribution and, consequently, the associated pressure distribution are determined analytically. The steady and unsteady behaviors of the developed model are validated against experimental and computational results. The model is then used to determine the lift frequency response at different mean angles of attack. Both qualitative and quantitative discrepancies are found between the obtained frequency response and that of Theodorsen at high angles of attack.
AB - A semi-analytical, geometrically-exact, unsteady potential flow model is developed for airfoils undergoing large amplitude maneuvers. For this objective, the classical unsteady theory of Theodorsen is revisited relaxing some of the major assumptions such as (1) flat wake, (2) small angle of attack, (3) small disturbances to the mean flow components, and (4) time-invariant free-stream. The kinematics of the wake vortices is simulated numerically while the wake and bound circulation distribution and, consequently, the associated pressure distribution are determined analytically. The steady and unsteady behaviors of the developed model are validated against experimental and computational results. The model is then used to determine the lift frequency response at different mean angles of attack. Both qualitative and quantitative discrepancies are found between the obtained frequency response and that of Theodorsen at high angles of attack.
KW - High angle of attack
KW - Theodorsenfrequency response
KW - Unsteady aerodynamics
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U2 - 10.1016/j.ast.2014.09.021
DO - 10.1016/j.ast.2014.09.021
M3 - Article
AN - SCOPUS:84908446935
SN - 1270-9638
VL - 39
SP - 293
EP - 306
JO - Aerospace Science and Technology
JF - Aerospace Science and Technology
ER -