Evaluation of Weighted Residual Methods for the Solution of the Chemical Reactor Pellet Model Equations

Author(s):  
J. Solsvik ◽  
S. Tangen ◽  
H.A. Jakobsen
Author(s):  
Lamiae Vernieres-Hassimi ◽  
Ahmed Abdelghani-Idrissi ◽  
Dominique Seguin ◽  
Nordine Mouhab

Abstract The unsteady state temperature of the reactive mixture along a tubular reactor presents a maximum value resulting from the exothermicity of the chemical reaction.The knowledge of the maximum temperature, (position and value) is an important indicator for safety and quality of reactors in which a highly exothermic reaction takes place. This paper deals with experimental and theoretical estimation and localization of this maximum temperature along a chemical tubular reactor at unsteady state. This reactor is equipped with a jacket in which the refrigerating fluid flows in counter current configuration.The reaction undertaken in the inner tube of the reactor is oxidation of sodium thiosulfate by hydrogen peroxide.The unsteady state is described from the resolution of the model equations, obtained from mass and energy balances, with the numerical method of McCormack.The influences of hydrodynamic, thermal and chemical parameters on the value and position of the maximum temperature are studied.


1994 ◽  
Vol 19 (6) ◽  
pp. 721-733 ◽  
Author(s):  
M. Neufeld ◽  
R. Friedrich

The study of the transport and capture of particles moving in a fluid flow in a porous medium is an important problem of underground hydromechanics, which occurs when strengthening loose soil and creating watertight partitions for building tunnels and underground structures. A one-dimensional mathematical model of long-term deep filtration of a monodisperse suspension in a homogeneous porous medium with a dimensional particle retention mechanism is considered. It is assumed that the particles freely pass through large pores and get stuck at the inlet of small pores whose diameter is smaller than the particle size. The model takes into account the change in the permeability of the porous medium and the permissible flow through the pores with increasing concentration of retained particles. A new spatial variable obtained by a special coordinate transformation in model equations is small at any time at each point of the porous medium. A global asymptotic solution of the model equations is constructed by the method of series expansion in a small parameter. The asymptotics found is everywhere close to a numerical solution. Global asymptotic solution can be used to solve the inverse filtering problem and when planning laboratory experiments.


1982 ◽  
Author(s):  
S.G. Metchis ◽  
A.S. Foss
Keyword(s):  

Author(s):  
Vladimir Lantsov ◽  
A. Papulina

The new algorithm of solving harmonic balance equations which used in electronic CAD systems is presented. The new algorithm is based on implementation to harmonic balance equations the ideas of model order reduction methods. This algorithm allows significantly reduce the size of memory for storing of model equations and reduce of computational costs.


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