Non-Newtonian effects in flows of some elastico-viscous liquids in curved channels

Résumé On considère l'écoulement initial de certains liquides non-newtoniens dans un canal courbe (borné par les parois d'un tuyau et un noyau de retenue) qui commence quand les forces contraignant le liquide de couler en lignes courbes le long du canal cessent subitement d'agir. On donne des calculs explicites dans les cas où les limites rigides sont (i) des parois excentriques et circulaires et (ii) des parois confocales et elliptiques.     

The numerical simulation of multiphase flow through a porous medium and its application to reservoir engineering

The analysis of multiphase flow in porous media is of considerable significance in the field of petroleum reservoir simulation, where accurate predictions of fluid flow are important in assessing the performance of oil and gas fields. The specific case of two-phase immiscible flow is considered by first deriving the governing nonlinear partial differential equations. The space discretization is then carried out making use of the additional versatility of the finite element method compared with originally used finite differences. By using a pair of dependent variables P and R, the bandwidth of the discrete space-continuous time equations may be reduced to increase significantly the speed of the algorithm. A discussion of time-stepping methods is followed by an application of the technique to a five-spot,an extraction pattern used in the field. The boundary conditions used to simulate this flow pattern are also discussed.     

Subseries convergence in topological groups and vector spaces

LetG be a separable complete metric additive topological group; it is shown that if a series Σx _n is subseries convergent in any weaker Hausdorff group topology onG, then Σx _n converges inG. This result can be used to obtain various extensions of the classical Orlicz-Pettis Theorem on subseries convergence in locally convex spaces.