The terminal velocity of several cylinders (of glass, perspex and stainless steel) falling with their axis parallel to the direction of motion has been measured in a series of Newtonian fluids embracing a 40-fold variation in liquid viscosity. The measurements have been carried out in fall tubes of four different diameters to elucidate the importance of wall effects. The experimental results encompass the following ranges of conditions: cylinder to fall tube diameter ratio: 0.08 to 0.4; length to diameter ratio: 0.05 to 2 and Reynolds number varied from 0.2 to 180.The wall effects are discussed in a manner analogous to those for spherical particles. Terminal velocity data are analysed using two approaches, namely, drag coefficient-Reynolds number relationship and a dimensionless velocity ratio denoting the departure from the behaviour of an equivalent sphere. Predictive equations have been developed using both schemes.LA vitesse terminale de plusieurs cylindres (de verre, de Plexiglas et d'acier inoxydable) tombant de telles sorte que leur axe principal est confondu avec la direction de chute, a Cte mesurC dans une serie de fluides newtoniens dont la ganime de viscosite varie d'un facteur 40. Des mesures ont 6tC effectuees dans des tubes de quatre diametres differents pour comprendre I'importance des effets de parois. Les resultats experimentaux englobent les conditions suivantes: rapport cylindre-diambtre du tube entre 0.08 et 0.4; rapport longueur-diamktre entre 0.05 et 2 ; et nombre de Reynolds conipris entre 0,2 et 180.Les effets de parois sont examines comme dans le cas des particules spheriques. On a analyse les donnees de vitesse terminale par deux approches, a savoir, la relation entre le coefficient de trainee et le nombre de Reynolds et un rapport de vitesse sans dimension representant I'Ccart par rapport au comportement d'une sphere Cquivalente. On a mis au point des modeles prCdictifs en utilisant ces deux approches.

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Shear-driven flow between a rotating cylinder and a stationary elliptical enclosure is studied in this paper. Two-dimensional time-dependent Navier–Stokes equations are solved using a meshless method, where interpolations are done with polyharmonic spline radial basis functions. The fluid flow is analyzed for various aspect ratios of the ellipse and eccentric placements of the inner cylinder. Contour plots of vorticity with streamlines, plots of non-dimensional torque, and the angle of eye of the primary vortex are presented in the paper for Reynolds numbers between 200 and 2000. Formation of Moffatt like vortices in the wide-gap region of the model is observed, and some benchmark data are provided for various cases that are simulated.

New experimental results on the hindered settling of model glass bead suspensions in non‐Newtonian suspending media are reported. The data presented encompass the following ranges of variables: 7.38 × 10−4 ≤ Re1∞ ≤ 2; 0.0083 ≤ d/D ≤ 0.0703; 0.13 ≤ C ≤ 0.43 and 1 ≥ n ≥ 0.8. In these ranges of conditions, the dependence of the hindered settling velocity on concentration is adequately represented by the corresponding Newtonian expressions available in the literature. The influence of the power law flow behaviour index is completely embodied in the modified definition of the Reynolds number used for power law liquids.

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