Exact and approximate equations for the kinetics of absorption for a linear isotherm in the case of a finite rate of surface mass exchange

1968 ◽  
Vol 17 (10) ◽  
pp. 2285-2287
Author(s):  
P. P. Zolotarev
Keyword(s):  
Mass Exchange ◽  
Finite Rate ◽  
Surface Mass ◽  
Linear Isotherm ◽  
Kinetics Of ◽  
Approximate Equations

Asymptotic analysis of premixed burning with large activation energy

1972 ◽  
Vol 56 (1) ◽  
pp. 81-95 ◽  
Author(s):  
Francis E. Fendell
Keyword(s):  
Laminar Flame ◽  
Lewis Number ◽  
Spherically Symmetric ◽  
Arrhenius Kinetics ◽  
Finite Rate ◽  
Activation Temperature ◽  
One Dimensional ◽  
First Order ◽  
Monomolecular Decomposition ◽  
Kinetics Of

The structure and propagation rates of premixed flames are determined by singular perturbation in the limit where the activation temperature is large relative to other flow temperatures for several basic flows. Specifically, the simple kinetics of an exothermic first-order monomolecular decomposition under Arrhenius kinetics is studied for one-dimensional laminar flame propagation, spherically symmetric quasi-steady monopropellant droplet burning, and other simple geometries. Results elucidate Lewis-number effects, losses owing to fuel gasification processes, and conditions under which the thin-flame approximation is a limit of finite-rate Arrhenius kinetics.

scholarly journals Isothermal Dynamics of the Adsorption of Multicomponent Mixtures

1988 ◽  
Vol 5 (2) ◽  
pp. 94-105 ◽  
Author(s):  
L.K. Filippov
Keyword(s):  
Porous Medium ◽  
Mass Exchange ◽  
Multicomponent Mixture ◽  
Theoretical Models ◽  
Multicomponent Mixtures ◽  
Mixture Adsorption ◽  
Limited Applicability ◽  
Kinetics Of ◽  
Porous Grains ◽  
Exchange Parameters

Theoretical models for the isothermal dynamics of the adsorption of multicomponent mixtures have been classified. The conditions determining a given frontal behaviour have been shown to depend on the type of theoretical model employed, on the kind of the adsorption isotherm and on the values of the mass exchange parameters inside and outside the porous grains in the porous medium. It has been shown that S type models of the kinetics of interphase mass exchange occurring within porous grains are of limited applicability, whereas the C type appears to be more sensible. Formulae for calculating the quantities determining the frontal behaviour for multicomponent mixture adsorption have been derived.

Kinetics of polymer crystallization - I. Discrete and continuum models

1988 ◽  
Vol 416 (1851) ◽  
pp. 443-461 ◽  
Keyword(s):  
Crystal Structure ◽  
One Dimensional ◽  
Ising Antiferromagnet ◽  
Equilibrium Distributions ◽  
Rate Processes ◽  
Lamellar Crystals ◽  
Kinetics Of ◽  
Dynamic Reversibility ◽  
Approximate Equations ◽  
The Continuum

The kinetics of growth of lamellar crystals by chain folding of polymer molecules are described by Markov rate processes whose states are representations of the edge of a lamella. The dynamic reversibility of these processes allows their equilibrium distributions to be found and these describe states of steady crystal growth. For a hexagonal crystal structure the equilibrium distribution is the Gibbs distribution for a constrained, one-dimensional Ising antiferromagnet. For a square crystal structure it is a constrained exponential distribution. These distributions provide a description of the roughness of the edge of a growing crystal and expressions for the growth rate. The continuum limit of these models is shown to coincide with the model of Frank and of Bennett et al . ( J. statist. Phys . 24, 419 (1981)). Frank’s approximate equations (Frank, F. C. J. Cryst. Growth 22, 233 (1974)) are also examined.

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