Two-Step Exothermic Chemical Reaction for Heat Transfer Investigation in a Convective Cylinder

In this article, analysis of heat transfer in a stockpile of reactive materials modelled in a rectangular slab is carried out. A two-step exothermic chemical reaction is assumed and the heat loss to the surrounding environment is by radiation. The ordinary differential equation (ODE) governing the problem is tackled numerically by Runge-Kutta Fehlberg (RKF45) method coupled with Shooting technique. The heat transfer analysis is simplified by investigation some kinetic parameters’ effects on the temperature of the combusting system. It was found out that some kinetic parameters raise the levels of the temperature by encouraging the exothermic chemical reaction, whereas some, reduce the levels of the temperature to slow down the heat transfer rate. The results are depicted graphically and discussed accordingly.

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On Heat Transfer of a Two-Step Radiating Slab of Variable Thermal Conductivity

Materials Science Forum ◽

10.4028/www.scientific.net/msf.987.137 ◽

2020 ◽

Vol 987 ◽

pp. 137-141

Author(s):

Ramoshweu Solomon Lebelo

Keyword(s):

Heat Transfer ◽

Thermal Conductivity ◽

Chemical Reaction ◽

Combustion Process ◽

Variable Thermal Conductivity ◽

Nonlinear Ordinary Differential Equation ◽

Physical Parameters ◽

Exothermic Chemical Reaction ◽

Temperature Levels ◽

Heat Transfers

An investigation of heat transfers in a combustible stockpile whose materials are of variable thermal conductivity is conducted in this article. The stockpile is modeled in rectangular slap and a two-step exothermic chemical reaction responsible for the combustion process is assumed. The reactive slab is also assumed to lose heat to the ambient by radiation. The Runge-Kutta Fehlberg (RKF45) method coupled with the Shooting technique is applied to tackle numerically the nonlinear ordinary differential equation (ODE) governing the problem. The process of heat transfer during combustion is made easy to understand by investigating effects of selected thermo-physical parameters on the system’s temperature. The results show that some thermo-physical parameters accelerate the exothermic chemical reaction and therefore raise the temperature levels, and that others help to reduce heat release rate to lower the temperature profiles. The graphs for the results are plotted and discussed accordingly.

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Analysis of Heat Transfer in a Triangular Enclosure Filled with a Porous Medium Saturated with Magnetized Nanofluid Charged by an Exothermic Chemical Reaction

Mathematical Problems in Engineering ◽

10.1155/2019/7451967 ◽

2019 ◽

Vol 2019 ◽

pp. 1-19

Author(s):

Raees-ul-Haq Muhammad

Keyword(s):

Heat Transfer ◽

Chemical Reaction ◽

Volume Fraction ◽

Physical Phenomenon ◽

Convection Heat Transfer ◽

Numerical Procedure ◽

Boussinesq Approximation ◽

Brownian Diffusion ◽

Model Parameters ◽

Exothermic Chemical Reaction

This paper intends to numerically study the steady-state free convection heat transfer in the presence of an exothermal chemical reaction governed by Arrhenius kinetics within a right-angled enclosure of triangular shape filled by porous media saturated with magnetized nanofluid. An approximation named as Darcy–Boussinesq approximation along with a nanofluid model mathematically propounded by Buongiorno has been implemented to model physical phenomenon representing fluid flow, heat transfer, and nanoparticle concentration. The mathematical equations in a dimensionless form describing the stream function for circulation of the fluid, the energy equation for heat, and nanoparticle volume fraction for concentration are solved using the finite difference method. The validity of the numerical procedure is established by comparing present results with the formerly available works in both statistical and graphical approaches. Streamlines, isotherms, and isoconcentrations are plotted and discussed for the various parametric regimes. The graphical description depicts that the average Nusselt and Sherwood numbers are the decreasing function of the Rayleigh number. The study revealed the accountable influence of model parameters such as thermophoresis and Brownian diffusion on the local Sherwood number, whereas a minimum impact on the local Nusselt number is observed.

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Modeling and Simulations of Buongiorno’s Model for Nanofluid in a Microchannel with Electro-Osmotic Effects and an Exothermal Chemical Reaction

Nanomaterials ◽

10.3390/nano11040905 ◽

2021 ◽

Vol 11 (4) ◽

pp. 905

Author(s):

Ammarah Raees ◽

Muhammad Raees-ul-Haq ◽

Muavia Mansoor

Keyword(s):

Heat Transfer ◽

Chemical Reaction ◽

Momentum Equation ◽

Dimensionless Numbers ◽

Buongiorno’S Model ◽

Slip Boundary ◽

Flow And Heat Transfer ◽

Exothermic Chemical Reaction ◽

Nanoparticles Concentration ◽

Osmotic Effects

The article presents a mathematical model for the magnetized nanofluid flow and heat transfer with an exothermic chemical reaction controlled by Arrhenius kinetics. Buongiorno’s model with passive boundary condition is employed to formulate the governing equation for nanoparticles concentration. The momentum equation with slip boundary conditions is modelled with the inclusion of electroosmotic effects which remain inattentive in the study of microchannel flows with electric double layer (EDL) effects. Conclusions are based on graphical and numerical results for the dimensionless numbers representing the features of heat transfer and fluid flow. Frank-Kamenetskii parameter resulting from the chemical reaction showed significant effects on the optimization of heat transfer, leading to increased heat exchangers’ effectiveness. The Hartmann number and slip parameter significantly affect skin friction, demonstrating the notable effects of electroosmotic flow and the exothermic chemical reaction on heat transfer in microchannels. This analysis contributes to prognosticating the convective heat transfer of nanofluids on a micro-scale for accomplishing successful thermal designs.

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Thermal Stresses in Chemically Hardening Elastic Media With Application to the Molding Process

Journal of Applied Mechanics ◽

10.1115/1.3423364 ◽

1974 ◽

Vol 41 (3) ◽

pp. 647-651 ◽

Cited By ~ 16

Author(s):

Myron Levitsky ◽

Bernard W. Shaffer

Keyword(s):

Residual Stress ◽

Chemical Reaction ◽

Thermal Stresses ◽

Stress Component ◽

Elastic Solid ◽

Molding Process ◽

Hardening Process ◽

Exothermic Chemical Reaction ◽

Component Parallel

A method has been formulated for the determination of thermal stresses in materials which harden in the presence of an exothermic chemical reaction. Hardening is described by the transformation of the material from an inviscid liquid-like state into an elastic solid, where intermediate states consist of a mixture of the two, in a ratio which is determined by the degree of chemical reaction. The method is illustrated in terms of an infinite slab cast between two rigid mold surfaces. It is found that the stress component normal to the slab surfaces vanishes in the residual state, so that removal of the slab from the mold leaves the remaining residual stress unchanged. On the other hand, the residual stress component parallel to the slab surfaces does not vanish. Its distribution is described as a function of the parameters of the hardening process.

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Impact of autocatalytic chemical reaction in an Ostwald-de-Waele nanofluid flow past a rotating disk with heterogeneous catalysis

Scientific Reports ◽

10.1038/s41598-021-94918-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Bai Yu ◽

Muhammad Ramzan ◽

Saima Riasat ◽

Seifedine Kadry ◽

Yu-Ming Chu ◽

...

Keyword(s):

Heat Transfer ◽

Thermal Conductivity ◽

Differential Equations ◽

Chemical Reaction ◽

Power Law ◽

Variable Thickness ◽

Rotating Disk ◽

Thermal Profile ◽

Nanofluid Flow ◽

Power Law Index

AbstractThe nanofluids owing to their alluring attributes like enhanced thermal conductivity and better heat transfer characteristics have a vast variety of applications ranging from space technology to nuclear reactors etc. The present study highlights the Ostwald-de-Waele nanofluid flow past a rotating disk of variable thickness in a porous medium with a melting heat transfer phenomenon. The surface catalyzed reaction is added to the homogeneous-heterogeneous reaction that triggers the rate of the chemical reaction. The added feature of the variable thermal conductivity and the viscosity instead of their constant values also boosts the novelty of the undertaken problem. The modeled problem is erected in the form of a system of partial differential equations. Engaging similarity transformation, the set of ordinary differential equations are obtained. The coupled equations are numerically solved by using the bvp4c built-in MATLAB function. The drag coefficient and Nusselt number are plotted for arising parameters. The results revealed that increasing surface catalyzed parameter causes a decline in thermal profile more efficiently. Further, the power-law index is more influential than the variable thickness disk index. The numerical results show that variations in dimensionless thickness coefficient do not make any effect. However, increasing power-law index causing an upsurge in radial, axial, tangential, velocities, and thermal profile.

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