Transient Response in a One-Dimensional Model of Thermoelastic Contact

1996 ◽  
Vol 63 (3) ◽  
pp. 575-581 ◽  
Author(s):  
Z. S. Olesiak ◽  
Yu. A. Pyryev
Keyword(s):  
Boundary Conditions ◽  
Nonlinear Problem ◽  
Transient Response ◽  
Computational Simulation ◽  
Linear Equations ◽  
Numerical Results ◽  
System Of Equations ◽  
Dimensional Model ◽  
One Dimensional ◽  
Method Of Solution

We consider two layers of different materials with the initial gap between them in the field of temperature with imperfect boundary conditions in Barber’s sense. The model we discuss is that of two contacting rods (Barber and Zhang, 1988) which in the case of a single rod was devised and discussed by Dundurs and Comninou (1976, 1979). In this paper we try to make a step further in the investigation of the essentially nonlinear problem. Though we consider a system of the linear equations of thermoelasticity the nonlinearity is induced by the boundary conditions dependent on the solution. We present an algorithm for solving the system of equations based on Laplace’s transform technique. The method of solution can be used also in the dynamical problems with inertial terms taken into account. The numerical results have been obtained by a kind of computational simulation.

BATCH DOUGH VISCOSITY INFLUENCE ON FLOW-PRESSURE CHARACTERISTICS OF THE KNEADING MACHINE

2019 ◽  
Author(s):  
В.С. РУБАН ◽  
В.И. АЛЕШИН ◽  
Д.С. БЕЗУГЛЫЙ
Keyword(s):  
Batch Process ◽  
System Of Equations ◽  
Systems Of Equations ◽  
The Finite Element Method ◽  
Dimensional Model ◽  
Symmetric Form ◽  
Pressure Function ◽  
One Dimensional ◽  
Flow Pressure ◽  
Transport Problems

Рассмотрены уравнения баланса и концентрационных потоков, базирующихся на моделях, позволяющих анализировать одноименные модели реологии течения в канале шнека блока замеса тестомесильной машины. Анализ процесса транспортировки и замеса на основе одномерной модели выявил необходимость использования сигмоидальной функции коэффициента напоропроводности от давления. Переход от одномерных задач к многомерным задачам переноса связан с преобразованием систем уравнений к симметричному виду. Полученные системы уравнений после использования теоремы Грина могут быть решены методом конечных элементов. The balance equation and concentration flows based on the models which make it possible to analyze the eponymous models of flow rheology in the block screw channel in a dough mixing machine has been considered. The analysis of the transportation and batch process based on one-dimensional model proved the necessity to apply sigmoidal coefficient of pressure function. The transition from one-dimensional problems to multidimensional transport problems is associated with the transformation of systems of equations to a symmetric form. The resulting system of equations after using Green’s theorem can be solved by the finite element method.

Effective Shear Area in One Dimensional Ship Hull Finite Element Models to Predict Natural Frequencies of Vibration

2013 ◽  
Author(s):  
Osvaldo Pinheiro de Souza e Silva ◽  
Severino Fonseca da Silva Neto ◽  
Ilson Paranhos Pasqualino ◽  
Antonio Carlos Ramos Troyman
Keyword(s):  
Finite Element ◽  
Natural Frequencies ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Numerical Results ◽  
Computational Method ◽  
Scale Model ◽  
Dimensional Model ◽  
One Dimensional ◽  
Shear Area

This work discusses procedures used to determine effective shear area of ship sections. Five types of ships have been studied. Initially, the vertical natural frequencies of an acrylic scale model 3m in length in a laboratory at university are obtained from experimental tests and from a three dimensional numerical model, and are compared to those calculated from a one dimensional model which the effective shear area was calculated by a practical computational method based on thin-walled section Shear Flow Theory. The second studied ship was a ship employed in midshipmen training. Two models were made to complement some studies and vibration measurements made for those ships in the end of 1980 decade when some vibration problems in them were solved as a result of that effort. Comparisons were made between natural frequencies obtained experimentally, numerically from a three dimensional finite element model and from a one dimensional model in which effective shear area is considered. The third and fourth were, respectively, a tanker ship and an AHTS (Anchor Handling Tug Supply) boat, both with comparison between three and one dimensional models results out of water. Experimental tests had been performed in these two ships and their results were used in other comparison made after the inclusion of another important effect that acts simultaneously: the added mass. Finally, natural frequencies experimental and numerical results of a barge are presented. The natural frequencies numerical results of vertical hull vibration obtained from these approximations of effective shear areas for the five ships are finally discussed.

scholarly journals Dissociation and recombination in the electrolyte flow model

2021 ◽  
Vol 2090 (1) ◽  
pp. 012076
Author(s):  
A Shobukhov ◽  
H Koibuchi
Keyword(s):  
Flow Model ◽  
Numerical Solutions ◽  
Stable Equilibrium ◽  
Steady State Solution ◽  
System Of Equations ◽  
Constant Flow ◽  
Dimensional Model ◽  
Electrolyte Flow ◽  
One Dimensional ◽  
Dilute Aqueous Solution

Abstract We propose a one-dimensional model for the dilute aqueous solution of NaCl which is treated as an incompressible fluid placed in the external electric field. This model is based on the Poisson-Nernst-Planck system of equations, which also contains the constant flow velocity as a parameter and considers the dissociation and the recombination of ions. We study the steady-state solution analytically and prove that it is a stable equilibrium. Analyzing the numerical solutions, we demonstrate the importance of dissociation and recombination for the physical meaningfulness of the model.

scholarly journals Well-Posed Lateral Boundary Conditions for Spectral Semi-Implicit Semi-Lagrangian Schemes: Tests in a One-Dimensional Model

2009 ◽  
Vol 137 (1) ◽  
pp. 315-330 ◽  
Author(s):  
F. Voitus ◽  
P. Termonia ◽  
P. Bénard
Keyword(s):  
Boundary Conditions ◽  
Weather Prediction ◽  
Implicit Time ◽  
Lateral Boundary ◽  
Dimensional Model ◽  
One Dimensional ◽  
Lateral Boundary Conditions ◽  
Boundary Treatment ◽  
Truncation Scheme ◽  
Well Posed

Abstract The aim of this paper is to investigate the feasibility of well-posed lateral boundary conditions in a Fourier spectral semi-implicit semi-Lagrangian one-dimensional model. Two aspects are analyzed: (i) the complication of designing well-posed boundary conditions for a spectral semi-implicit scheme and (ii) the implications of such a lateral boundary treatment for the semi-Lagrangian trajectory computations at the lateral boundaries. Straightforwardly imposing boundary conditions in the gridpoint-explicit part of the semi-implicit time-marching scheme leads to numerical instabilities for time steps that are relevant in today’s numerical weather prediction applications. It is shown that an iterative scheme is capable of curing these instabilities. This new iterative boundary treatment has been tested in the framework of the one-dimensional shallow-water equations leading to a significant improvement in terms of stability. As far as the semi-Lagrangian part of the time scheme is concerned, the use of a trajectory truncation scheme has been found to be stable in experimental tests, even for large values of the advective Courant number. It is also demonstrated that a well-posed buffer zone can be successfully applied in this spectral context. A promising (but not easily implemented) alternative to these three above-referenced schemes has been tested and is also presented here.

Design Considerations for Aerodynamically Quenching Gas Sampling Probes

1984 ◽  
Vol 106 (2) ◽  
pp. 460-466 ◽  
Author(s):  
L. Chiappetta ◽  
M. B. Colket
Keyword(s):  
Sensitivity Study ◽  
Operating Conditions ◽  
Dimensional Model ◽  
Quenching Temperature ◽  
One Dimensional ◽  
Trade Offs ◽  
Transfer Equations ◽  
Method Of Solution ◽  
Internal Aerodynamics ◽  
Temperature And Pressure

An aerodynamic quench is the most rapid method for quenching temperature and pressure-dependent chemical reactions. Attempts have been made to quench gas samples aerodynamically, but many of these attempts have been unsuccessful because of a lack of understanding of the internal aerodynamics of sampling probes. A one-dimensional model developed previously by the authors has been used for the design and analysis of aerodynamically quenching probes. This paper presents in detail the important aerodynamic and heat transfer equations used in the model, a description of the method of solution, and the results of a sensitivity study. These calculations demonstrate the limitations and important trade-offs in design and operating conditions of probes using an aerodynamic quench.

scholarly journals An Improved One-Dimensional Model for Liquid Slugs Traveling in Pipelines

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Arris S. Tijsseling ◽  
Qingzhi Hou ◽  
Zafer Bozkuş
Keyword(s):  
Experimental Data ◽  
Flow Separation ◽  
Parameter Variation ◽  
Numerical Results ◽  
Driving Pressure ◽  
Dimensional Model ◽  
Liquid Slug ◽  
Straight Pipe ◽  
One Dimensional ◽  
1D Model

An improved one-dimensional (1D) model—compared to previous work by the authors—is proposed, which is able to predict the acceleration and shortening of a single liquid slug propagating in a straight pipe with a downstream bend. The model includes holdup at the slug's tail and flow separation at the bend. The obtained analytical and numerical results are validated against experimental data. The effects of holdup, driving pressure and slug length are examined in a parameter variation study.

Modeling of a Torch Ignition System Using One-Dimensional Model of Computational Simulation

2014 ◽  
Author(s):  
T. A. A. MOREIRA ◽  
P. H. AMBRÓSIO ◽  
F. T. BORGHI ◽  
L. B. MINETI ◽  
A. C. NEVES ◽  
...  
Keyword(s):  
Computational Simulation ◽  
Dimensional Model ◽  
Ignition System ◽  
One Dimensional
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