Subject: Engineering, Automotive Engineering Keywords: Reaction engineering; Catalysis; particle; multiplicity; parallel reactions; consecutive reactions;
Online: 17 March 2021 (11:13:56 CET)
The steady-state multiplicity of the porous, non-isothermal, catalyst pellet when two parallel and consecutive chemical reactions take place was analysed in this work. The geometry selected for the catalyst pellet is finite hollow cylinder. A numerical multigrid continuation technique with the preconditioned conjugate gradient squared as coarse grid solver was used. The continuation parameter is the dimensionless adiabatic heat rise (Prater number) for the first chemical reaction. The effect of the other governing parameters was analysed and the results are compared to those provided by the single chemical reaction.
ARTICLE | doi:10.20944/preprints202104.0249.v1
Subject: Engineering, Automotive Engineering Keywords: conjugate heat transfer; convection-radiation; Rosseland approximation; P1 approximation; finite difference; defect correction - multigrid.
Online: 8 April 2021 (17:57:29 CEST)
The effect of thermal radiation on the two – dimensional, steady-state, conjugate heat transfer from a circular cylinder with an internal heat source in steady laminar crossflow is investigated in this work. P0 (Rosseland) and P1 approximations were used to model the radiative transfer. The mathematical model equations were solved numerically. Qualitatively, P0 and P1 approximations show the same effect of thermal radiation on conjugate heat transfer; the increase in the radiation – conduction parameter decreases the cylinder surface temperature and increases the heat transfer rate. Quantitatively, there are significant differences between the results provided by the two approximations.
ARTICLE | doi:10.20944/preprints202109.0469.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: heat transfer; mass transfer; convection-radiation; surface reaction; diffusion approximation; finite difference.
Online: 28 September 2021 (11:38:54 CEST)
The steady-state, coupled heat and mass transfer from a fluid flow to a sphere accompanied by an exothermal catalytic chemical reaction on the surface of the sphere is analysed taking into consideration the effect of thermal radiation. The flow past the sphere is considered steady, laminar and incompressible. The radiative transfer is modeled by P0 and P1 approximations. The mathematical model equations were discretized by the finite difference method. The discrete equations were solved by the defect correction – multigrid method. The influence of thermal radiation on the sphere surface temperature, concentration and reaction rate was analysed for three parameter sets of the dimensionless reaction parameters. The numerical results show that only for very small values of the Prater number the effect of thermal radiation on the surface reaction is not significant.