Deep stall characterization and identification algorithm on a T-tail aircraft model

Laurent Hetru (1) , Thierry M. Faure (1, 2) , Sebastien Kolb (1) , Olivier Montagnier (3, 1)

1 CReA - Centre de recherche de l'armée de l'air
2 LIMSI - Laboratoire d'Informatique pour la Mécanique et les Sciences de l'Ingénieur
3 M&S - Matériaux et Structures

Deep stall is a kind of stall affecting aircraft longitudinal dynamics in which the pitch up/down command is almost ineffective. The flight of the tail inside the separated wake of the stalled main wing could be considered as an explanation for the phenomenon. It implies a stable equilibrium at high angle of attack. The analysis is first performed from the observation that the different possible types of time evolutions in the (alpha, q) phase portrait are only in limited number. Then the damping of the short period mode near deep stall is noted to be smaller than the one at low angle-of-attack. At the end, the analysis of the dynamics proves to allow the identification of critical deep stall prone flight conditions without any a priori information on the aircraft.

Mots clés: Deep Stall; Flight Dynamics

Domaines: Mécanique des fluides [physics.class-ph]

Laurent Hetru, Thierry M. Faure, Sebastien Kolb, Olivier Montagnier. Deep stall characterization and identification algorithm on a T-tail aircraft model. 50th 3AF International Conference on Applied Aerodynamics, Association Aéronautique et Astronautique de France - 3AF, Mar 2015, Toulouse, France. 6 p. ⟨hal-01138936⟩