Cylinder

About: Cylinder is a research topic. Over the lifetime, 65503 publications have been published within this topic receiving 372954 citations. The topic is also known as: cylindrical.

Experimental determination of the main features of the viscous flow in the wake of a circular cylinder in uniform translation. Part 2. Unsteady flow

Abstract: A visualization method is used to obtain the main features of the hydrodynamic field for flow past a circular cylinder moving at a uniform speed in a direction perpendicular to its generating lines in a tank filled with a viscous liquid. Photographs are presented to show the particular fineness of the experimental technique. More especially, the closed wake and the velocity distribution behind the obstacle are investigated; the changes in the geometrical parameters describing the eddies with Reynolds number (5 < Re < 40) and with the ratio λ between the diameters of the cylinder and tank are given. A comparison with existing numerical and experimental results is presented and some remarks are made about the calculation techniques proposed up to the present. The limits of the Reynolds-number range for which the twin vortices exist and adhere stably to the cylinder are determined.

Gently sloping turning device

Abstract: FIELD: medicine, particularly, surgical and stomatologic instruments. SUBSTANCE: device has remote-control mechanism in the form of main internal cylinder and external control cylinder. External cylinder is fitted with handle for rotation and locking. External cylinder has eccentric turning rod at its end. Rod enters corresponding recess made in intermediate part of body which consists of hinge-connected parts with central channel. Hinge-connected parts of body are made with pairs of end-face coupling surfaces positioned at an angle to longitudinal axis of body and with axles oriented perpendicularly to end-face coupling surfaces. Axles are provided with central channel and bevel gears at their ends. Intermediate part of body with recess corresponding to rod is located between end-face coupling surfaces. As result, device may be used in body of almost any surgical instrument or some other manipulator for easy and quick variation of deflection angle of instrument operating parts from longitudinal axis of body within wide range. EFFECT: higher efficiency. 3 cl, 3 dwg

Direct analysis of particulate suspensions with inertia using the discrete Boltzmann equation

Abstract: An efficient and robust computational method, based on the lattice-Boltzmann method, is presented for analysis of impermeable solid particle(s) suspended in fluid with inertia. In contrast to previous lattice-Boltzmann approaches, the present method can be used for any solid-to-fluid density ratio. The details of the numerical technique and implementation of the boundary conditions are presented. The accuracy and robustness of the method is demonstrated by simulating the flow over a circular cylinder in a two-dimensional channel, a circular cylinder in simple shear flow, sedimentation of a circular cylinder in a two-dimensional channel, and sedimentation of a sphere in a three-dimensional channel. With a solid-to-fluid density ratio close to one, new results from two-dimensional and three-dimensional computational analysis of dynamics of an ellipse and an ellipsoid in a simple shear flow, as well as two-dimensional and three-dimensional results for sedimenting ellipses and prolate spheroids, are presented.

Kinetics of swelling and shrinking of gels

Abstract: The kinetics of swelling and shrinking of gels is theoretically generalized and experimentally studied. A new relation, in addition to the differential equation developed by Tanaka and Fillmore, is formulated to solve the kinetics of gels having arbitrary shape. Using our new theory, we provide explicit solutions for long cylinder and large disk gels. These solutions predict that the effective diffusion constants of long cylinder and large disk gels are 1.5 and 3 times smaller than that of a spherical gel. The relaxation times of long cylinder and large disk gels with small shear modulus μ are approximately 2.0 and 5.7 times longer than that of a sphere, where the diameters of the cylinder and the sphere and the thickness of the disk are the same. The theory also concludes that the experimentally measured kinetics of a long cylinder and disk gels along the z axis and the radial axis are the same. The results have been excellently confirmed by the experiments.