Download or read book Multiscale Simulation of Transient Viscoelastic Free Surface Flows written by Mohit Bajaj and published by . This book was released on 2006 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analysis of Transient Viscoelastic Flows Involving a Free Surface written by Douglas Wayne Bousfield and published by . This book was released on 1986 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Simulation of Transient Viscoelastic Flows with Two Free Surfaces written by Wenqun Mao and published by . This book was released on 1994 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: "In this thesis, we examine the numerical simulation of transient viscoelastic flows with two moving free surfaces. A modified Galerkin finite element method is implemented to the two-dimensional non-steady motion of a viscoelastic fluid. The fluid is initially placed between two parallel plates and bounded by two straight free boundaries. In this Lagrangian finite element method, the spatial mesh deforms in time along with the moving free boundaries. The unknown shape of free surfaces is determined with the flow field u, v, $ tau$, p by the deformable finite element method, combined with a predictor-corrector scheme in an uncoupled fashion. In this study, the moving free surfaces and fluid motion of both Newtonian and non-Newtonian flows are investigated. The results include the influence of the time increment and the finite element mesh size, the effects of surface tension, fluid inertia and elasticity." --

Download or read book Numerical Simulation of Transient Viscoelastic Flows with Two Free Surfaces microform written by Wenqun Mao and published by National Library of Canada = Bibliothèque nationale du Canada. This book was released on 1994 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Simulation of Viscoelastic Free Surface Flows written by Philipp Knechtges and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Multiscale Simulation of Viscoelastic Flows written by Jason Ka-Chun Suen and published by . This book was released on 2003 with total page 726 pages. Available in PDF, EPUB and Kindle. Book excerpt: (Cont.) Simulations of the original Doi model with the Maier-Saupe potential in a pressure-driven channel flow by Nayak showed disclination formation due to the shear-rate-dependent frequencies of the tumbling/wagging states of the Doi model in a shear or mixed shear flow. The lack of an instrinsic length scale in the model leads to an infinitesimal structure refinement that eventually causes numerical instabilities. In this thesis, the effect of concentration variation is incorporated to develop a modified Doi model for introducing an intrinsic length scale through translational diffusion. This changes the mathematical characteristics of the spatial variation of the underlying diffusion equation from that of a hyperbolic equation to that of an elliptic equation. The resulting elliptic diffusion equation is then solved by using a local discontinuous Galerkin method, where an auxillary variable is introduced to rewrite the elliptic diffusion equation into a pair of formal, hyperbolic equations, which in turn is solved by the standard discontinuous Galerkin method. Unlike the original Doi model, a steady state is reached for a variety of De. Although there is structure variation across the channel width, the director profiles point uniformly along the flow direction. The lack of disclination formation may be rectified by introducing Frank elasticity into the modified Doi model ...

Download or read book Numerical Simulation of Transcient i e Transient Planar Flow of a Viscoelastic Material with Two Moving Free Surfaces written by and published by . This book was released on 1995 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Simulation of Viscoelastic Free surface Flows Using a Streamfunction written by Raphaël Comminal and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Simulations of Viscoelastic Flow in Complex Geometries Using a Multi mode Giesekus Model written by Wan-Chi Tsai and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a convergent and stable numerical algorithm to simulate unsteady incompressible viscoelastic flow in two dimensional complex geometry. The incompressible viscous momentum equation, coupled with the multiple mode Giesekus constitutive equation for viscoelastic stress, are used to model viscoelastic fluids in our problems. We recast the hyperbolic part of equations to a second order conservative finite difference method and leave the elliptic part as a source term to be computed by implicit methods. A second order Godunov method is introduced to compute edge-centered, time-centered primitive variables for calculating fluxes in a conservative finite difference equation, and then cell-centered conservative variables are updated using a hybrid flux divergence and source terms. The nonlinear stress source term in the elliptic part is computed separately by applying an operator splitting method with a new, stable, discretization. A projection method is used to enforce the velocity incompressibility constraint and to update pressure. Irregular computational domains are discretized with a Cartesian grid embedded boundary method. We demonstrate our numerical method by computing flow passing a sphere, flow in a well-rounded contraction channel, and in an abrupt contraction channel, with component Weissenberg numbers exceeding 300. The convergence rates of the solution error are second order in the L1 and L2 norms, and first order in the L[infinity] norm for velocity components in arbitrary smooth geometries. For stress components, this numerical algorithm showed second order convergence rate in the L1 norm, higher than first order in the L2 norm.

Download or read book Modeling of Three dimensional Viscoelastic Flows with Free Surfaces Using a Finite Element Method written by David Joseph Adrian and published by . This book was released on 2010 with total page 275 pages. Available in PDF, EPUB and Kindle. Book excerpt: A framework and code have been developed to simulate fiber and film processes; the code can handle three-dimensional, isothermal, incompressible, creeping flow of a Giesekus fluid with free surfaces at infinite capillary number. The code is an extension of the parallel methods developed by Caola et al. from two- to three-dimensional flows, a restructured and improved version of the three-dimensional code of Phillips based on the subproblem formulation. The free surface motion used is an extension of the axially-constrained finite difference method of Phillips from two to three dimensions; internal domain deformation is upgraded from an elliptic mapping technique, only suitable for two-dimensional geometries, to the treatment of the domain as a fictitious elastic solid that conforms to the free surface, similar to the methods of Cairncross et al. The verification of the code and its utility are tested against the ability to capture experimental behavior in a set of benchmark problems which benefit from its ability to compute fully three-dimensional flow fields. Fluids with a nonzero second normal stress difference in simple shear flow, such as Giesekus fluids, exhibit secondary flows in non-circular, non-annular pipes. The code predicts the fully-developed three-dimensional velocity field in flow of a square duct in agreement with Yue et al. Elastically-driven flow transitions from a two-dimensional, steady flow to a three-dimensional, time periodic flow also motivate the need for three-dimensional solvers, which should be able to capture the onset directly. Flow around a closely-spaced linear periodic array of cylinders in a rectangular channel, a flow studied experimentally by Liu, exhibits this kind of flow transition. Numerical simulations have been conducted in this geometry with the Oldroyd-B model, [beta] = 0.67, wall separation distances between 4-32 radii, and Deborah number 0.1

Download or read book Numerical Study of Free Surface Viscoelastic Flows written by R. Sizaire and published by . This book was released on 1997 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Simulation of Transient Nonlinear Free surface Flows with Body Interaction written by Vincent Saubestre and published by . This book was released on 1990 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dynamics and Friction Drag Behavior of Viscoelastic Flows in Complex Geometries written by Anantha Padmanabha Rao Koppol and published by . This book was released on 2007 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Computational Fluid Dynamics Model for Transient Three dimensional Free Surface Flows written by John Ferney McKibben and published by . This book was released on 1993 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High Resolution Modeling of Multiscale Transient Phenomena in Turbulent Boundary Layers written by and published by . This book was released on 2001 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: High fidelity numerical simulation of wall-bounded turbulence requires physically sound representation of the small scale unsteady processes governing near-wall momentum, heat, and mass transfer. Conventional wall treatments do not capture the diverse multiphysics flow regimes relevant to engineering applications. To obtain a robust yet computationally affordable near-wall submodel for turbulent flow computations, the fine-grained spatial structure and time evolution of the near-wall flow is simulated using a model formulated on a 1D domain corresponding to the wall-normal direction. This approach captures the strong variation of flow properties in the wall-normal direction and the transient interactions between this highly inhomogeneous region and the more nearly homogeneous (at fine scales) flow farther from the wall. The 1D simulation utilizes the One Dimensional Turbulence (ODT) methodology, whose formulation for the present application is described in detail. Demonstrations of ODT performance with regard to aspects of flow physics relevant to near-wall flow modeling are presented. The coupling of ODT to a large eddy simulation (LES) of confined turbulent flow is described, and the performance of the coupled formulation is demonstrated. It is concluded that this formulation has the potential to provide the fidelity needed for engineering applications at an affordable computational cost.

Download or read book Numerical Simulation of Complex Viscoelastic Flows Using Discontinuous Galerkin Spectral hp Element Methods written by Susanne Claus and published by . This book was released on 2013 with total page 249 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Simulation of 3D Turbulent Free surface Flows written by Takafumi Kawamura and published by . This book was released on 1998 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: