The Kitanidis filter is a natural extension of the Kalman filter to systems subject to arbitrary disturbances or unknown inputs. Though the optimality of the Kitanidis filter was founded for general time varying systems more than 30 years ago, its stability analysis is still limited to time invariant systems, to the author's knowledge. In the frame...
Crack nucleation has been the subject of important contributions in the two last decades. However, it seems that few attention has been granted to the case of saturated porous media. This is the question adressed in the present paper which is devoted to nucleation in traction mode. From a physical point of view, nucleation is a sudden phenomenon, s...
The present article aims at optimising the spread of a bifurcating jet: a jet that combines axisymmetric and helical forcing to achieve increased mixing in a preferential plane. Parekh et al. (Tech. Rep. TF-35, Stanford University, 1988) explained such a bifurcation as the result of nonlinear interaction between ring vortices (triggered by m D 0 ax...
Ces travaux s'inscrivent dans la résolution de problèmes couplés aérothermiques. Il s'agit notamment d'améliorer les méthodes de couplage en termes de précision et de robustesse. La stabilité du couplage aérothermique en régime permanent a été d'abord étudiée (couplage faible). Un nombre de Biot numérique a été défini ce qui permet d'évaluer l'inte...
BORY, OlivierBOUCHEMELLA, SamilaDUBREUCQ, ThierryFLEUREAU, Jean MarieFry, Jean JacquesTaibi, Said
Les calculs de stabilité des barrages en remblai sont couramment menés en contraintes effectives avec les résistances mesurées sur les sols constitutifs du remblai parfaitement saturés. De nombreux remblais depuis leur mise en eau ont des piézométries rabattues par le filtre central et des déplacements stabilisés. Cette situation pérenne laisse à p...
The objective of the present study is to explain the evolution of the transonic buffet phenomenon from two-dimensional airfoils to three-dimensional swept wings by a global stability analysis. With respect to two-dimensional buffet, shock oscillation frequency increases by a factor of 4 to 7 in the case of a swept 30◦ wing and three-dimensional pat...
The design and assessment of a two degree of freedom gust load allevi-ation control system for a business jet aircraft is presented in this paper. The two degrees of freedom are a disturbance estimator to compute the incoming gusts as well as a feedback control law to mitigate the estimated disturbance to reduce the aircraft loads. To facilitate th...