scholarly journals Entropy production and Onsager symmetry in neoclassical transport processes of toroidal plasmas

1996 ◽  
Vol 3 (1) ◽  
pp. 304-322 ◽  
Author(s):  
H. Sugama ◽  
W. Horton
Keyword(s):  
Entropy Production ◽  
Transport Processes ◽  
Toroidal Plasmas ◽  
Onsager Symmetry ◽  
Neoclassical Transport

Symmetries of and entropy production by transport in toroidal confinement systems

1998 ◽  
Vol 59 (4) ◽  
pp. 695-706 ◽  
Author(s):  
H. SUGAMA ◽  
W. HORTON
Keyword(s):  
Entropy Production ◽  
Transport Process ◽  
Collision Operator ◽  
Positive Definite ◽  
Anomalous Transport ◽  
The Self ◽  
Entropy Production Rate ◽  
Onsager Symmetry ◽  
Neoclassical Transport ◽  
Linearized Collision Operator

A synthesized formulation of classical, neoclassical and anomalous transport in toroidal confinement systems with electromagnetic fluctuations and large mean flows is presented. The positive-definite entropy production rate and the conjugate flux–force pairs are rigorously defined for each transport process. The Onsager symmetries of the classical and neoclassical transport matrices are derived from the self-adjointness of the linearized collision operator. The linear gyrokinetic equation with given electromagnetic fluctuations determines the anomalous fluxes with the quasilinear anomalous transport matrix, which satisfies the Onsager symmetry.

scholarly journals Transport processes and entropy production in toroidal plasmas with gyrokinetic electromagnetic turbulence

1996 ◽  
Vol 3 (6) ◽  
pp. 2379-2394 ◽  
Author(s):  
H. Sugama ◽  
M. Okamoto ◽  
W. Horton ◽  
M. Wakatani
Keyword(s):  
Entropy Production ◽  
Transport Processes ◽  
Toroidal Plasmas

Local Entropy Production Rates in a Polymer Electrolyte Membrane Fuel Cell

2017 ◽  
Vol 42 (1) ◽  
pp. 1-30 ◽  
Author(s):  
Marc Siemer ◽  
Tobias Marquardt ◽  
Gerardo Valadez Huerta ◽  
Stephan Kabelac
Keyword(s):  
Fuel Cell ◽  
Entropy Production ◽  
Polymer Electrolyte ◽  
Polymer Electrolyte Membrane ◽  
Gas Diffusion ◽  
Transport Processes ◽  
Local Entropy ◽  
Equilibrium Thermodynamics ◽  
Electrolyte Membrane ◽  
Non Equilibrium

AbstractA modeling study on a polymer electrolyte membrane fuel cell by means of non-equilibrium thermodynamics is presented. The developed model considers a one-dimensional cell in steady-state operation. The temperature, concentration and electric potential profiles are calculated for every domain of the cell. While the gas diffusion and the catalyst layers are calculated with established classical modeling approaches, the transport processes in the membrane are calculated with the phenomenological equations as dictated by the non-equilibrium thermodynamics. This approach is especially instructive for the membrane as the coupled transport mechanisms are dominant. The needed phenomenological coefficients are approximated on the base of conventional transport coefficients. Knowing the fluxes and their intrinsic corresponding forces, the local entropy production rate is calculated. Accordingly, the different loss mechanisms can be detected and quantified, which is important for cell and stack optimization.

scholarly journals A convergence study for the Laguerre expansion in the moment equation method for neoclassical transport in general toroidal plasmas

2010 ◽  
Vol 17 (8) ◽  
pp. 082510 ◽  
Author(s):  
S. Nishimura ◽  
H. Sugama ◽  
H. Maaßberg ◽  
C. D. Beidler ◽  
S. Murakami ◽  
...  
Keyword(s):  
Moment Equation ◽  
Equation Method ◽  
Laguerre Expansion ◽  
Toroidal Plasmas ◽  
Neoclassical Transport ◽  
Convergence Study ◽  
The Moment

CRYSTAL GROWTH AND THE THERMODYNAMICS OF IRREVERSIBLE PROCESSES

1959 ◽  
Vol 37 (6) ◽  
pp. 739-754 ◽  
Author(s):  
J. S. Kirkaldy
Keyword(s):  
Free Energy ◽  
Steady State ◽  
Entropy Production ◽  
Dendritic Growth ◽  
Transport Processes ◽  
Irreversible Processes ◽  
Interface Morphology ◽  
Crystal Face ◽  
Thermodynamics Of Irreversible Processes ◽  
Alloy Crystal

The principle of minimum rate of entropy production is applied to steady-state transport processes in the neighborhood of an alloy crystal face growing into its melt. The procedure gives a satisfactory rationale of observed interface morphology. It is noted that segregation, which occurs in cellular or dendritic growth of alloys, is a direct manifestation of the system's attempt to minimize entropy production by conserving free energy. The general problems of growth of pure and impure single crystals from the melt and vapor are discussed.

Sign in / Sign up

Export Citation Format

Share Document