Showing papers on "Shell balance published in 2007"

Navier–Stokes Equations Interacting with a Nonlinear Elastic Biofluid Shell

Abstract: We study a moving boundary value problem consisting of a viscous incompressible fluid moving and interacting with a nonlinear elastic fluid shell. The fluid motion is governed by the Navier–Stokes equations, while the fluid shell is modeled by a bending energy which extremizes the Willmore functional and a membrane energy with density given by a convex function of the local area ratio. The fluid flow and shell deformation are coupled together by continuity of displacements and tractions (stresses) along the moving surface defining the shell. We prove the existence and uniqueness of solutions in Sobolev spaces for a short time.

Flow past a porous approximate spherical shell

Abstract: In this paper, the creeping flow of an incompressible viscous liquid past a porous approximate spherical shell is considered. The flow in the free fluid region outside the shell and in the cavity region of the shell is governed by the Navier–Stokes equation. The flow within the porous annulus region of the shell is governed by Darcy’s Law. The boundary conditions used at the interface are continuity of the normal velocity, continuity of the pressure and Beavers and Joseph slip condition. An exact solution for the problem is obtained. An expression for the drag on the porous approximate spherical shell is obtained. The drag experienced by the shell is evaluated numerically for several values of the parameters governing the flow.

The Influence of Actuator Parameters on Fluid Jetting Dispensing

Abstract: The actuator is an important component of the fluid jet-dispenser,and has an important influence on the fluid volume and velocity of the fluid jetted from the jet-dispenserThe calculation formula of cumulative fluid volume and its equivalent velocity based on fluid kinetic energy are deduced through central velocity at the nozzle outlet from the numerical simulation result,then cumulative fluid volume and equivalent velocity are computed under the condition of different actuator parameters by MATLAB programThis research supplies some foundation for the design and operation adjustment of the actuatorThe results show a good changeing characteristic of the cumulative fluid volume and equivalent velocity,the stroke of the ball-needle compared with its acceleration has less influence on the jetting fluid dispensing

Fluid Pressure on Rectangular Rigid Tanks Due to Uplift Motion

Abstract: This paper mathematically derives fluid pressure on a rectangular rigid tank with unit depth, which models a section of a center part of a flat-bottom cylindrical shell tank, accompanied with uplift motion. Employing boundary conditions consisting of fluid velocity imparted by motion of the side walls and bottom plate of the tank along with uplifting, the equation of continuity of fluid given by the Laplace equation is solved as the parabolic partial differential equation of Neumann problem. The fluid pressure is given by a function of the velocity potential. Comparison of mathematical results with numerical ones based on explicit FE analysis corroborates its accuracy and applicability on design procedure of flat-bottom cylindrical shell tanks.Copyright © 2007 by ASME

Dynamical Behaviour of Plates Subjected to a Flowing Fluid

Abstract: In this paper we describe the development of a fluid-solid finite element to model plates subjected to flowing fluid under various boundary conditions. The mathematical model for the structure is developed using a combination of the finite element method and Sanders' shell theory. The membrane displacement field is approximated by bilinear polynomials and the transversal displacement by an exponential function. Fluid pressure is expressed by inertial, Coriolis and centrifugal fluid forces. Bernoulli's equation for the fluid-solid interface and partial differential equation of potential flow are applied to calculate the fluid pressure. Calculated results are in agreement with other analytical theories.

Analysis on the deformation and internal force of an elastic thin cylindrical shell in fluid

Abstract: The basic fluid-solid interaction formulas for a shell in fluid are given using elasticity theory of thin shells and fundamental equations of fluid mechanics. The united Lagrangian-Eulerian method is proposed and used to form the equations for the small bending of a cylindrical shell with a surrounding transverse flow, and then the velocity potential of the fluid field as well as the deformation and the internal force distribution of the shell are obtained. Using a specific example, the fluid field figures are obtained, and the effects of parameters on the deformation of the shell and pressure coefficient of the shell surface are discussed.