Transport Processes in Magnetosolidmechanics

1966 ◽  
Vol 33 (4) ◽  
pp. 770-776 ◽  
Author(s):  
M. R. El-Saden ◽  
O. A. Arnas
Keyword(s):  
Three Dimensional ◽  
Second Law Of Thermodynamics ◽  
Irreversible Thermodynamics ◽  
Transport Processes ◽  
Governing Equations ◽  
Electrical Currents ◽  
One Dimensional ◽  
Current Densities ◽  
Galvanomagnetic Effects ◽  
State Case

Consideration is given to the problem of a solid conducting heat and electrical currents in the presence of externally applied magnetic fields. Interactions due to the thermoelectric, thermomagnetic, and galvanomagnetic effects are taken into consideration. The general three-dimensional governing equations are established. The generalized Ohm’s law and Fourier’s law of heat conduction as formulated by the methods of nonequilibrium (irreversible) thermodynamics are employed. The governing equations are used for the analysis of a one-dimensional steady-state case, assuming constant thermophysical properties. The variations of temperature, electric field, magnetic field, and electric and thermal current densities are presented analytically and graphically. The second law of thermodynamics imposes certain limitations on the validity of the results. These limitations are discussed in detail.

Transport Processes in Magnetosolidmechanics-Adiabatic Conditions

1969 ◽  
Vol 36 (1) ◽  
pp. 107-112
Author(s):  
O. A. Arnas ◽  
G. T. Craig
Keyword(s):  
Magnetic Field ◽  
Steady State ◽  
Applied Magnetic Field ◽  
Irreversible Thermodynamics ◽  
Transport Processes ◽  
One Dimensional ◽  
Adiabatic Conditions ◽  
Basic Concepts ◽  
General Relations ◽  
State Case

General phenomenological relations describing the interactions between an externally applied magnetic field and thermal and electrical gradients in a solid are formulated from basic concepts of irreversible thermodynamics. Galvanomagnetic and thermomagnetic effects are defined under adiabatic conditions and the results obtained are compared with previous analyses under isothermal conditions. The general relations are applied to a one-dimensional steady-state case.

scholarly journals Numerical Solution and Application of Time-Space Fractional Governing Equations of One-Dimensional Unsteady Open Channel Flow Process

2016 ◽  
Author(s):  
Ali Ercan ◽  
M. Levent Kavvas
Keyword(s):  
Channel Flow ◽  
Open Channel ◽  
Open Channel Flow ◽  
Transport Processes ◽  
Governing Equations ◽  
Flow Process ◽  
One Dimensional ◽  
Time Space ◽  
Flow Processes ◽  
Saint Venant Equations

Abstract. Although fractional integration and differentiation have found many applications in various fields of science, such as physics, finance, bioengineering, continuum mechanics and hydrology, their engineering applications, especially in the field of fluid flow processes, are rather limited. In this study, a finite difference numerical approach is proposed to solve the time-space fractional governing equations of one-dimensional unsteady/non-uniform open channel flow process. By numerical simulations, results of the proposed fractional governing equations of the open channel flow process were compared with those of the standard Saint Venant equations. Numerical simulations showed that flow discharge and water depth can exhibit heavier tails in downstream locations as space and time fractional derivative powers decrease from 1. The fractional governing equations under consideration are generalizations of the well-known Saint Venant equations, which are written in the integer differentiation framework. The new governing equations in the fractional order differentiation framework have the capability of modeling nonlocal flow processes both in time and in space by taking the global correlations into consideration. Furthermore, the generalized flow process may shed light into understanding the theory of the anomalous transport processes and observed heavy tailed distributions of particle displacements in transport processes.

Time-Split Inflow Boundary Treatment

1985 ◽  
Author(s):  
Siu Shing Tong
Keyword(s):  
Three Dimensional ◽  
Internal Flow ◽  
Leading Edge ◽  
Two Dimensional ◽  
Governing Equations ◽  
Internal Flows ◽  
One Dimensional ◽  
Boundary Treatment

This paper describes a new non-reflective inflow treatment for viscous and inviscid internal flow calculations. The method approximates the multi-dimensional governing equations at the inflow boundary in a series of one-dimensional split equations. This treatment allows the artificial inflow boundary to be brought in just in front of the leading edge, while allowing upstream running waves to penetrate without significant reflection. Calculation examples of two dimensional inviscid internal flows are presented. Extension of the method to three-dimensional problems is also discussed.

scholarly journals The Coastline Evolution Model 2D (CEM2D) V1.1

2021 ◽  
Vol 14 (9) ◽  
pp. 5507-5523
Author(s):  
Chloe Leach ◽  
Tom Coulthard ◽  
Andrew Barkwith ◽  
Daniel R. Parsons ◽  
Susan Manson
Keyword(s):  
Sediment Transport ◽  
Three Dimensional ◽  
Transport Processes ◽  
Evolution Model ◽  
One Dimensional ◽  
Coastline Evolution ◽  
Fundamental Cause ◽  
Formation And Evolution ◽  
Three Dimensional Models ◽  
Variable Water

Abstract. Coasts are among the most intensely used environments on the planet, but they also present dynamic and unique hazards, including flooding and erosion. Sea level rise and changing wave climates will alter patterns of erosion and deposition, but some existing coastline evolution models are unable to simulate these effects due to their one-dimensional representation of the systems or the sediment transport processes. In this paper, the development and application of the Coastline Evolution Model 2D (CEM2D) are presented, a model which incorporates these influences. The model has been developed from the established CEM and is capable of simulating fundamental cause–effect relationships in coastal systems. The two-dimensional storage and transport of sediment in CEM2D, which are only done in one-dimension in CEM, mean it is also capable of exploring the influence of a variable water level on sediment transport and the formation and evolution of morphological features and landforms at the mesoscale. The model sits between one-dimensional and three-dimensional models, with the advantage of increased complexity and detail in model outputs compared to the former but with more efficiency and less computational expense than the latter.

scholarly journals On Maxwell Electrodynamics in Multi-Dimensional Spaces

Universe ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 20
Author(s):  
Alexei M. Frolov
Keyword(s):  
Electromagnetic Field ◽  
Maxwell Equations ◽  
Three Dimensional ◽  
Governing Equations ◽  
Tensor Form ◽  
Action Function ◽  
One Dimensional ◽  
Least Action ◽  
Maxwell Electrodynamics ◽  
Principle Of Least Action

The governing equations of Maxwell electrodynamics in multi-dimensional spaces are derived from the variational principle of least action, which is applied to the action function of the electromagnetic field. The Hamiltonian approach for the electromagnetic field in multi-dimensional pseudo-Euclidean (flat) spaces has also been developed and investigated. Based on the two arising first-class constraints, we have generalized to multi-dimensional spaces a number of different gauges known for the three-dimensional electromagnetic field. For multi-dimensional spaces of non-zero curvature the governing equations for the multi-dimensional electromagnetic field are written in a manifestly covariant form. Multi-dimensional Einstein’s equations of metric gravity in the presence of an electromagnetic field have been re-written in the true tensor form. Methods of scalar electrodynamics are applied to analyze Maxwell equations in the two and one-dimensional spaces.

A Theoretical Analysis of One-Dimensional Nonsteady Muscular Contraction

1974 ◽  
Vol 41 (2) ◽  
pp. 327-331 ◽  
Author(s):  
John A. Steen ◽  
H. H. Chiu ◽  
Augusto H. Moreno
Keyword(s):  
Three Dimensional ◽  
Muscular Contraction ◽  
Irreversible Thermodynamics ◽  
Physical Parameters ◽  
Specific Information ◽  
Contractile State ◽  
One Dimensional ◽  
Internal Function ◽  
Dimensional Element ◽  
General Physical

Most of the existing theories of muscle contraction rely primarily on specific information of the internal function of the system. These theories are generally based on mechanics or chemical kinetics models. We have previously proposed a general theory based on the laws of irreversible thermodynamics that requires only a general knowledge of the physical system. The theory has been derived in a form that is applicable to the three-dimensional, nonuniform, unsteady contraction of muscle. With a knowledge of the general physical parameters of the system, the solution of the equations would specify the force and shortening at each point in the muscle as a function of space and time. So far, we have solved the specific problem of the overall contraction of a uniform element of contractile material constrained to contract isometrically [1]. Presented herein is the response within a one-dimensional element of muscle rigidly attached at one end and acted upon by a sinusoidal force at the other end. The solution indicates that force and shortening within the muscle are composed mathematically of two sinusoidal waves moving in opposite directions. It is also seen that the maximum absolute value of the transfer function (from force to shortening) corresponds to an optimum physiological condition, where the passive elastic and active contractile responses combine to produce maximum work output. This suggests that a muscle at its optimum contractile state will shorten, against the same external force, a greater amount than when it was at a different contractile state. Application of the scheme of analysis to general nonsteady contractions of muscle, including the myocardium, is also indicated.

Performance Characteristics of Regenerative Flow Compressors for Natural Gas Compression Application

2005 ◽  
Vol 127 (1) ◽  
pp. 7-14 ◽  
Author(s):  
Mukarrum Raheel ◽  
Abraham Engeda
Keyword(s):  
Mathematical Model ◽  
Natural Gas ◽  
Three Dimensional ◽  
Governing Equations ◽  
One Dimensional ◽  
Gas Compression ◽  
And Performance ◽  
Regenerative Flow ◽  
Performance Results ◽  
Channel Region

In this paper we discuss the application of regenerative flow compressors (RFC) for low-pressure natural gas compression required by microturbine systems. A brief overview of fundamentals and the hypothesis of the operation of RFC is presented. A mathematical model to describe the complex three-dimensional corkscrew flow pattern in RFC is discussed. Governing equations for the blade and channel region are developed. A one-dimensional (1-D) performance prediction code for RFC based on governing equations and loss models is developed and performance results are compared with experimental data on a multistage RFC. Excellent agreement between theoretical and experimental results is observed, thus validating the proposed mathematical model.

Theory of Nonequilibrium Thermodynamics With Application to the Transport Processes in a Solid

1966 ◽  
Vol 88 (1) ◽  
pp. 57-61 ◽  
Author(s):  
M. R. El-Saden
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Nonequilibrium Thermodynamics ◽  
Three Dimensional ◽  
Transport Processes ◽  
Coupled Processes ◽  
Heat Current ◽  
One Dimensional ◽  
Electrical Phenomenon ◽  
The One

The theory of nonequilibrium thermodynamics for inherently irreversible coupled processes is presented and the concept of heat is incorporated appropriately. The theory was applied to the problem of a solid carrying electric and heat currents in the presence of an external magnetic field. The principle of increase of entropy was employed to determine the reversibility or irreversibility of the macroscopic effects involved and to determine the limits on the material’s properties. The dynamic equations show that, in the one-dimensional thermoelectric case, the heat current is not coupled to the electrical phenomenon. In two and three-dimensional cases, the heat current is coupled to the electrical phenomenon only through the influence of the external magnetic field. Areas of disagreement with the literature are pointed out and discussed.

scholarly journals The Coastline Evolution Model 2D (CEM2D) V1.1

2019 ◽  
Author(s):  
Chloe Leach ◽  
Tom Coulthard ◽  
Andrew Barkwith ◽  
Daniel R. Parsons ◽  
Susan Manson
Keyword(s):  
Sediment Transport ◽  
Three Dimensional ◽  
Transport Processes ◽  
Evolution Model ◽  
One Dimensional ◽  
Coastline Evolution ◽  
Fundamental Cause ◽  
Formation And Evolution ◽  
Three Dimensional Models ◽  
Variable Water

Abstract. Coasts are among the most intensely used environments on the planet, but they also present dynamic and unique hazards including flooding and erosion. Sea level rise and changing wave climates will alter patterns of erosion and deposition, but some existing coastline evolution models are unable to simulate these effects due to their one-dimensional representation of the systems, or of sediment transport processes. In this paper, the development and application of the Coastline Evolution Model 2D (CEM2D) is presented, that incorporates these influences. The model has been developed from the established CEM model and is capable of simulating fundamental cause-effect relationships in coastal systems. The two-dimensional storage and transport of sediment in CEM2D, which is only done in one-dimension in CEM, means it is also capable of exploring the influence of a variable water level on sediment transport and the formation and evolution of morphological features and landforms at the meso-scale, from 10 to 100 years and over 10 to 100 kilometres. The model sits between one-dimensional and three-dimensional models, with the advantage of increased complexity and detail in model outputs compared to the former, but with more efficiency and less computational expense than the latter.

Numerical model studies of the effect of injected nitrogen oxides on stratospheric ozone

1977 ◽  
Vol 355 (1681) ◽  
pp. 267-299 ◽  
Keyword(s):  
Nitrogen Oxides ◽  
General Circulation Model ◽  
General Circulation ◽  
Stratospheric Ozone ◽  
Three Dimensional ◽  
Circulation Model ◽  
Reaction Rates ◽  
Transport Processes ◽  
One Dimensional ◽  
Dimensional Models

The work reported here has employed one-dimensional models, in which atmospheric transport is represented in combination with chemical kinetic mechanisms, to compute average vertical distributions of the minor constituents of the stratosphere as a function of time. Perturbation experiments simulating the effects of exhaust emissions, particularly nitrogen oxides and water vapour, from supersonic and subsonic aircraft fleets have been performed. The effect on stratospheric ozone of a possible four year variation in tropospheric N 2 O levels from 1966 to 1969 has also been investigated. Inert tracer studies from a three-dimensional tropospheric and stratospheric general circulation model have been used to examine specific limitations of the representation of transport processes in one-dimensional models. The inability of current one-dimensional models to represent counter gradient transport of minor gaseous constituents by the mean global circulation is a serious shortcoming in their use for studies of this type; the importance of mean motions in the general circulation is demonstrated by diagnostic data from a three-dimensional general circulation model, and by reference to the production of nitrogen oxides in thunderstorms. Further subjects studied were the effects on the calculated ozone reductions of using different profiles of vertical eddy diffusivity, diurnal and seasonal time dependence of the solar zenith angle in the photochemistry and temperature dependence of the chemical reaction rates. It was also found that the effects of injections from the supersonic and subsonic fleets were not linearly additive in the one-dimensional diffusive models used in this study. The optimum latitude at which to operate a one-dimensional model is discussed; for injected species with long atmospheric lifetimes a value of 34° is recommended for the Northern Hemisphere.

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