A system of equations of motion of a nonlinear viscoelastic liquid suitable for describing the flow of linear polymers and filled systems based on linear polymers

1981 ◽  
Vol 17 (2) ◽  
pp. 202-205
Author(s):  
V. N. Pokrovskii ◽  
P. I. Taronov ◽  
V. B. �renburg
Keyword(s):  
Equations Of Motion ◽  
Viscoelastic Liquid ◽  
System Of Equations ◽  
Linear Polymers ◽  
Nonlinear Viscoelastic

scholarly journals Shallow water waves in a rotating rectangular basin

2000 ◽  
Vol 24 (10) ◽  
pp. 649-661 ◽  
Author(s):  
Mohamed Atef Helal
Keyword(s):  
Shallow Water ◽  
Water Waves ◽  
Equations Of Motion ◽  
System Of Nonlinear Equations ◽  
System Of Equations ◽  
Order Of Approximation ◽  
Shallow Water Waves ◽  
Nonlinear System Of Equations ◽  
Rectangular Basin ◽  
Shallow Water Approximation

This paper is mainly concerned with the motion of an incompressible fluid in a slowly rotating rectangular basin. The equations of motion of such a problem with its boundary conditions are reduced to a system of nonlinear equations, which is to be solved by applying the shallow water approximation theory. Each unknown of the problem is expanded asymptotically in terms of the small parameterϵwhich generally depends on some intrinsic quantities of the problem of study. For each order of approximation, the nonlinear system of equations is presented successively. It is worthy to note that such a study has useful applications in the oceanography.

scholarly journals Numerical solution for consistent initial conditions of constrained mechanical systems

2003 ◽  
Vol 25 (3) ◽  
pp. 170-185
Author(s):  
Dinh Van Phong
Keyword(s):  
Numerical Solution ◽  
Initial Conditions ◽  
Equations Of Motion ◽  
Mechanical Systems ◽  
Differential Algebraic Equations ◽  
System Of Equations ◽  
Algebraic Equations ◽  
Flexible Approach ◽  
Constrained Mechanical Systems ◽  
Consistent Initial Values

The article deals with the problem of consistent initial values of the system of equations of motion which has the form of the system of differential-algebraic equations. Direct treating the equations of mechanical systems with particular properties enables to study the system of DAE in a more flexible approach. Algorithms and examples are shown in order to illustrate the considered technique.

Theory of water waves derived from a Lagrangian. Part 1. Standing waves

2000 ◽  
Vol 423 ◽  
pp. 275-291 ◽  
Author(s):  
MICHAEL S. LONGUET-HIGGINS
Keyword(s):  
Gravity Waves ◽  
Water Waves ◽  
Fourier Coefficients ◽  
Equations Of Motion ◽  
Standing Waves ◽  
System Of Equations ◽  
Practical Applications ◽  
Low Degree ◽  
Sharp Corners ◽  
New System

A new system of equations for calculating time-dependent motions of deep-water gravity waves (Balk 1996) is here developed analytically and set in a form suitable for practical applications. The method is fully nonlinear, and has the advantage of essential simplicity. Both the potential and the kinetic energy involve polynomial expressions of low degree in the Fourier coefficients Yn(t). This leads to equations of motion of correspondingly low degree. Moreover the constants in the equations are very simple. In this paper the equations of motion are specialized to standing waves, where the coefficients Yn are all real. Truncation of the series at low values of [mid ]n[mid ], say n < N, leads to ‘partial waves’ with solutions apparently periodic in the time t. For physical applications N must however be large. The method will be applied to the breaking of standing waves by the forming of sharp corners at the crests, and the generation of vertical jets rising from the wave troughs.

Hydrodynamics of a Centrifugal Nonlinear-Viscoelastic Liquid Film

2019 ◽  
Vol 92 (4) ◽  
pp. 923-928
Author(s):  
N. Kh. Zinnatullin ◽  
G. N. Zinnatullina ◽  
E. I. Kul’ment’eva
Keyword(s):  
Liquid Film ◽  
Viscoelastic Liquid ◽  
Nonlinear Viscoelastic

scholarly journals ON THE DYNAMICS OF A QUADRATIC SCALAR FIELD POTENTIAL

2009 ◽  
Vol 18 (04) ◽  
pp. 621-634 ◽  
Author(s):  
L. ARTURO UREÑA-LÓPEZ ◽  
MAYRA J. REYES-IBARRA
Keyword(s):  
Scalar Field ◽  
Autonomous System ◽  
Equations Of Motion ◽  
Scalar Potential ◽  
Field Potential ◽  
System Of Equations ◽  
New Formalism ◽  
Slow Roll ◽  
Chaotic Model ◽  
Friedmann Robertson Walker

We review the attractor properties of the simplest chaotic model of inflation, in which a minimally coupled scalar field is endowed with a quadratic scalar potential. The equations of motion in a flat Friedmann–Robertson–Walker universe are written as an autonomous system of equations, and the solutions of physical interest appear as critical points. This new formalism is then applied to the study of inflation dynamics, in which we can go beyond the known slow-roll approximation.

A STRING MODEL FOR D-DIMENSIONAL DE SITTER SPACE–TIME AND EQUATIONS OF MOTION

2005 ◽  
Vol 20 (26) ◽  
pp. 6065-6081
Author(s):  
PAUL BRACKEN
Keyword(s):  
Evolution Equations ◽  
Gordon Equation ◽  
Equations Of Motion ◽  
String Model ◽  
De Sitter Space ◽  
Space Time ◽  
System Of Equations ◽  
De Sitter ◽  
Minkowski Space Time ◽  
Dimensional Minkowski Space

De Sitter space–time is considered to be represented by a D-dimensional hyperboloid embedded in (D+1)-dimensional Minkowski space–time. The string equation is derived from a string action which contains a Lagrange multiplier to restrict coordinates to de Sitter space–time. The string system of equations is equivalent to a type of generalized sinh–Gordon equation. The evolution equations for all the variables including the coordinates and their derivatives are obtained for D=2,3 and 4.

II. Determination of constitutive coefficients and illustrative examples

1989 ◽  
Vol 327 (1595) ◽  
pp. 449-475 ◽  
Keyword(s):  
Turbulent Flow ◽  
Constitutive Equations ◽  
Theoretical Calculations ◽  
Equations Of Motion ◽  
Plane Channel ◽  
General System ◽  
Turbulent Fluctuation ◽  
System Of Equations ◽  
Constitutive Response

This paper is a continuation of Part I under the same title and is concerned mainly with the determination of the constitutive response coefficients, as well as some simple illustrative examples. First, a system of simplified constitutive equations for incompressible viscous turbulent flow is obtained from the more general system of equations in Part I through a judicial choice of retaining only those terms which appear to represent major features of the turbulent flow. Even for this simplified system of equations, the identification of some of the constitutive coefficients presents a formidable task; and this is especially true in the case of those coefficients that are associated with the presence of the additional independent variables of the theory due to the manifestation of the alignment of eddies (on the microscopic scale), turbulent fluctuation and eddy density. Because of this difficulty, the present effort for identification of the various constitutive coefficients must be regarded partly as tentative, pending future availability of suitable relevant experimental data and/or pertinent numerical simulation results. Keeping this background in mind, most of the relevant coefficients in the constitutive equations are determined, or the nature of their functional forms are estimated, through consideration of‘cartoon-like’ models on the microscopic level and these results are then used in conjunction with the macroscopic equations of motion to examine a number of simple solutions. These include the possibility of a flow possessing a constant uniform velocity gradient and solutions pertaining to decay of flow anisotropy and plane turbulent channel flows. The predicted theoretical calculations are in general accord with experimental observations. In addition, for plane channel flow, plots of variation along the width of the channel for the turbulent temperature and the macroscopic velocity compare favourably with corresponding known experimental results.

Transient Response of Inelastically Constrained Rigid-Body Systems

1974 ◽  
Vol 96 (3) ◽  
pp. 1041-1047 ◽  
Author(s):  
K. C. Park ◽  
K. J. Saczalski
Keyword(s):  
Structural Material ◽  
Rigid Body ◽  
Transient Response ◽  
Equations Of Motion ◽  
Coupling Mechanism ◽  
System Of Equations ◽  
Structural System ◽  
Lagrangian Multipliers ◽  
Nonlinear Geometric ◽  
Incremental Equations

An energy rate balance is employed to develop the incremental equations of motion for a shock loaded, inelastically constrained rigid-body structural system. Lagrangian multipliers provide the coupling mechanism necessary to reduce the overall system of equations to a set of modified rigid-body equations which include the nonlinear geometric and structural material effects. Kinematic material hardening and a modified yield criteria are used. Examples illustrate the technique and are compared with experimental results.

scholarly journals Dynamical Codimension – 2 Brane in a Warped Six Dimensional Space-time

2018 ◽  
Vol 28 (3) ◽  
pp. 277
Author(s):  
Phan Hong Lien
Keyword(s):  
Einstein Equation ◽  
Dimensional Space ◽  
Equations Of Motion ◽  
Space Time ◽  
Cosmological Evolution ◽  
System Of Equations ◽  
Dimensional Space Time ◽  
Six Dimensions ◽  
Bulk Space

In this paper we present the Einstein equation extended in six-dimensions (6D) from the formation of codimension-2 brane, which is created by a 4-brane and 4-anti brane moving in the warped 6D “bulk” space-time. The system of equations of motion for the dynamical codimension - 2 brane has been derived to describe the cosmological evolution on the probe branes. Some cosmological consequences are investigated.

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