Mathematical analysis of solar conduction dryer using reaction engineering approach

2020 ◽  
Vol 18 (5-6) ◽  
Author(s):  
Anand Chavan ◽  
Bhaskar Thorat
Keyword(s):  
Heat Transfer ◽  
Activation Energy ◽  
Mass Transfer ◽  
Effective Diffusivity ◽  
Reaction Engineering ◽  
Agricultural Product ◽  
Heat Transfer Mechanism ◽  
Engineering Approach ◽  
Individual Mode ◽  
Relative Activation

AbstractSolar conduction dryer (SCD) utilizes all three modes of heat transfer, viz., conduction, convection, and radiation. The effect of individual mode of heat transfer in SCD on agricultural product drying was studied using drying kinetics and basic heat transfer calculations. It was observed that the order of influence of mode of heat transfer mechanism as conduction followed by radiation and then convection. The correlation for relative activation energy (∆Ev/∆Ev,∞) as a function of moisture content (X−X∞), effective diffusivity (Deff), and mass transfer coefficient (hm) were determined for each mode of heat transfer. It was observed that the reaction engineering approach (REA) is appropriate tool to understand the physics of drying mechanism in SCD.

scholarly journals Measuring REA-based drying kinetics through temperature-moisture content relationship

2018 ◽  
Author(s):  
Xiao Dong Chen ◽  
Aditya Putranto
Keyword(s):  
Heat Transfer ◽  
Activation Energy ◽  
Mass Transfer ◽  
Moisture Content ◽  
Mass Balance ◽  
Reaction Engineering ◽  
New Approach ◽  
Engineering Approach ◽  
Relative Activation ◽  
Drying Conditions

The reaction engineering approach (REA) has been proposed and implemented for modeling a number of challenging drying cases. While the modeling is simple and accurate, it is effective to generate the drying parameters. The relative activation energy is the fingerprint of the REA which describes the changes of internal behaviors inside the materials during drying. In this paper, a new method, based on combined heat and mass balance, is proposed and implemented to retrieve the relative activation energy of flat materials. The results indicate that the new approach can be used to retrieve well the activation energy of flat materials. The relative activation energy retrieved by the new approach is independent on the external drying conditions. This new approach can also potentially be used to evaluate the change of surface area of materials during drying Keywords: reaction engineering approach (REA);, modeling; relative activation energy; mass transfer;, heat transfer 

scholarly journals Impact of Binary Chemical Reaction and Activation Energy on Heat and Mass Transfer of Marangoni Driven Boundary Layer Flow of a Non-Newtonian Nanofluid

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 702
Author(s):  
Ramanahalli Jayadevamurthy Punith Gowda ◽  
Rangaswamy Naveen Kumar ◽  
Anigere Marikempaiah Jyothi ◽  
Ballajja Chandrappa Prasannakumara ◽  
Ioannis E. Sarris
Keyword(s):  
Heat Transfer ◽  
Activation Energy ◽  
Boundary Layer ◽  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Velocity Gradient ◽  
Boundary Layer Flow ◽  
Biological Fluids ◽  
Porosity Parameter ◽  
Layer Flow

The flow and heat transfer of non-Newtonian nanofluids has an extensive range of applications in oceanography, the cooling of metallic plates, melt-spinning, the movement of biological fluids, heat exchangers technology, coating and suspensions. In view of these applications, we studied the steady Marangoni driven boundary layer flow, heat and mass transfer characteristics of a nanofluid. A non-Newtonian second-grade liquid model is used to deliberate the effect of activation energy on the chemically reactive non-Newtonian nanofluid. By applying suitable similarity transformations, the system of governing equations is transformed into a set of ordinary differential equations. These reduced equations are tackled numerically using the Runge–Kutta–Fehlberg fourth-fifth order (RKF-45) method. The velocity, concentration, thermal fields and rate of heat transfer are explored for the embedded non-dimensional parameters graphically. Our results revealed that the escalating values of the Marangoni number improve the velocity gradient and reduce the heat transfer. As the values of the porosity parameter increase, the velocity gradient is reduced and the heat transfer is improved. Finally, the Nusselt number is found to decline as the porosity parameter increases.

Numerical investigation of heat and mass transfer during hydrogen sorption in a mixture of AB2 – AB5 metal hydride for hydrogen storage

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Mapula Lucey Moropeng ◽  
Andrei Kolesnikov ◽  
Mykhaylo Lototskyy ◽  
Avhafunani Mavhungu
Keyword(s):  
Heat Transfer ◽  
Activation Energy ◽  
Mass Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Heat And Mass Transfer ◽  
Metal Hydride ◽  
Sorption Process ◽  
Hydrogen Gas ◽  
Hydrogen Sorption

AbstractThis paper presents the investigation of a two dimensional coupled model of heat and mass transfer in a mixture of AB2 – AB5 metal hydride (MH) systems of a cylindrical configuration during hydrogen sorption using COMSOL 5.3a commercial software. The parametric study on the sorption process has been studied with variation of heat transfer coefficient (HTC), and activation energy (AE) to understand the effects they have on the reaction kinetics of the sorption process. The simulation results demonstrate the importance of mutual dependence between the temperature propagation in the body of metal hydride, the absorbed concentration of the hydrogen gas, and the gas pressure for the absorption of hydrogen gas in metal hydrides. The decrease in the activation energy is found to have significant effect on the dynamic performances of hydrogen absorption in the MH reactors with an increased amount of hydrogen conversion, whilst the variation of heat transfer coefficient displayed insignificant change in hydrogen conversion. The simulated results show good agreement with the experimental results obtained from HYSA Systems and were implemented for use in the STILL RX60-30L electric forklift fuel cell applications designed by HYSA Systems in the University of the Western Cape.

Flow and heat transfer over a permeable moving wedge in a hybrid nanofluid with activation energy and binary chemical reaction

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Nurul Amira Zainal ◽  
Roslinda Nazar ◽  
Kohilavani Naganthran ◽  
Ioan Pop
Keyword(s):  
Heat Transfer ◽  
Activation Energy ◽  
Mass Transfer ◽  
Chemical Reaction ◽  
Volume Fraction ◽  
Hybrid Nanofluid ◽  
Content Type ◽  
Transfer Rates ◽  
Flow And Heat Transfer ◽  
Moving Wedge

Purpose The analysis of boundary layers is needed to reflect the behaviour of fluid flows in current industrial processes and to improve the efficacy of products. Hence, this study aims to analyse the flow and heat transfer performance of hybrid alumina-copper/water (Al2O3-Cu/H2O) nanofluid with the inclusion of activation energy and binary chemical reaction effect towards a moving wedge. Design/methodology/approach The multivariable differential equations with partial derivatives are converted into a specific type of ordinary differential equations by using valid similarity transformations. The reduced mathematical model is elucidated in the MATLAB system by using the bvp4c procedure. This solution method is competent in delivering multiple solutions once appropriate assumptions are supplied. Findings The results of multiple control parameters have been studied, and the findings are verified to provide more than one solution. The coefficient of skin friction was discovered to be increased by adding nanoparticles volume fraction from 0% to 0.5% and 1%, by almost 1.6% and 3.2%. Besides, increasing the nanoparticles volume fraction improves heat transfer efficiency gradually. The inclusion of the activation energy factor displays a downward trend in the mass transfer rates, consequently reducing the concentration profile. In contrast, the increment of the binary reaction rate greatly facilitates the augmentation of mass transfer rates. There is a significant enhancement in the heat transfer rate, approximately 13.2%, when the suction effect dominates about 10% in the boundary layer flow. Additionally, the results revealed that as the activation energy rises, the temperature and concentration profiles rise as well. It is proved that the activation energy parameter boosts the concentration of chemical species in the boundary layer. A similar pattern emerges as the wedge angle parameter increases. The current effort aims to improve the thermal analysis process, particularly in real-world applications such as geothermal reservoirs, chemical engineering and food processing, which often encountered mass transfer phenomenon followed by chemical reactions with activation energy. Originality/value The present results are original and new for the study of flow and heat transfer over a permeable moving wedge in a hybrid nanofluid with activation energy and binary chemical reaction.

Magnetohydrodynamic flow of Carreau liquid over a stretchable sheet with a variable thickness

2020 ◽  
Vol 16 (5) ◽  
pp. 1277-1293 ◽  
Author(s):  
B. Mahanthesh
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Activation Energy ◽  
Mass Transfer ◽  
Differential Equations ◽  
Chemical Reaction ◽  
Variable Thickness ◽  
Transfer Rate ◽  
Content Type ◽  
Biomedical Sensors

PurposeThe magnetohydrodynamic (MHD) flow problems are important in the field of biomedical applications such as magnetic resonance imaging, inductive heat treatment of tumours, MHD-derived biomedical sensors, micropumps for drug delivery, MHD micromixers, magnetorelaxometry and actuators. Therefore, there is the impact of the magnetic field on the transport of non-Newtonian Carreau fluid in the presence of binary chemical reaction and activation energy over an extendable surface having a variable thickness. The significance of irregular heat source/sink and cross-diffusion effects is also explored.Design/methodology/approachThe leading governing equations are constructed by retaining the effects of binary chemical reaction and activation energy. Suitable similarity transformations are used to transform the governing partial differential equations into ordinary differential equations. Subsequent nonlinear two-point boundary value problem is treated numerically by using the shooting method based on Runge–Kutta–Fehlberg. Graphical results are presented to analyze the behaviour of effective parameters involved in the problem. The numerical values of the mass transfer rate (Sherwood number) and heat transfer rate (Nusselt number) are also calculated. Furthermore, the slope of the linear regression line through the data points is determined in order to quantify the outcome.FindingsIt is established that the external magnetic field restricts the flow strongly and serves as a potential control mechanism. It can be concluded that an applied magnetic field will play a major role in applications like micropumps, actuators and biomedical sensors. The heat transfer rate is enhanced due to Arrhenius activation energy mechanism. The boundary layer thickness is suppressed by strengthening the thickness of the sheet, resulting in higher values of Nusselt and Sherwood numbers.Originality/valueThe effects of magnetic field, binary chemical reaction and activation energy on heat and mass transfer of non-Newtonian Carreau liquid over an extendable surface with variable thickness are investigated for the first time.

Miniature Biomass Conversion Unit for Learning the Fundamentals of Heterogeneous Reactions through Analysis of Heat Transfer and Thermochemical Conversion

2020 ◽  
Vol 63 (4) ◽  
pp. 1019-1036
Author(s):  
Jacqueline B. Gartner ◽  
Olivia M. Reynolds ◽  
Manuel Garcia-Perez ◽  
David B. Thiessen ◽  
Bernard J. Van Wie
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Heterogeneous Reaction ◽  
Biomass Conversion ◽  
Reaction Engineering ◽  
Heterogeneous Reactions ◽  
Fractional Factorial ◽  
Thermochemical Conversion ◽  
Transfer Model ◽  
List Type

HighlightsA miniaturized thermochemical conversion system has been designed, manufactured, and optimized.Five laboratories can be performed with the system, incorporating heat transfer and reaction engineering phenomena.Educational materials to deploy the system in the classroom, including worksheets and solutions, are provided.Pyrolysis, combustion, and gasification exercises are shown with reaction visualization and product validation.Abstract. We describe a simple new miniaturized thermochemical module (MTM). Special considerations are needed to make the MTM useful not only for studying biomass conversion but also for providing safe classroom learning opportunities for heat and mass transfer and heterogeneous reaction engineering students and for training new researchers. The MTM consists of a quartz reactor wrapped with a Kanthal resistance wire and a silvered concentric annular glass shield for retaining thermal energy, placed in a protective Plexiglas viewing case. Safety is considered for use by new research trainees and within the classroom. We demonstrate MTM usage through five laboratory exercises beginning with an experimental design to determine operating modes to establish thermochemical conversion temperatures. Heat transfer skills are developed with the aid of a first-order differential heat transfer model and fractional factorial design. Thermochemical conversion is demonstrated and products are validated for pyrolysis, gasification, and combustion. The combustion laboratory also offers significant insight into reaction versus mass transfer-controlled regimes and for modeling heat transfer. Discussion is provided on the utility of the system for demonstrating heat transfer, kinetic, and mass transfer concepts, with applications across the engineering curriculum. Keywords: Combustion, Education, Gasification, Heat transfer modeling, Miniature thermochemical module, Pyrolysis.

Arrhenius Activation Energy Effect on a Stagnation Point Slippery MHD Casson Nanofluid Flow with Entropy Generation and Melting Heat Transfer

2021 ◽  
Vol 408 ◽  
pp. 1-18
Author(s):  
Tunde Abdulkadir Yusuf ◽  
Toyin Wasiu Akaje ◽  
Sulyman O. Salawu ◽  
Jacob Abiodun Gbadeyan
Keyword(s):  
Heat Transfer ◽  
Activation Energy ◽  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Stagnation Point ◽  
Entropy Generation ◽  
Casson Fluid ◽  
Arrhenius Activation Energy ◽  
Melting Heat ◽  
Melting Heat Transfer

This study features the entropy generation analysis on a steady two-dimensional flow of an incompressible Casson fluid with heat and mass transfer over a heated linearly stretching surface is investigated using a modified Arrhenius activation energy. The appropriate model governing the physical phenomenon is converted into a dimensionless equation with the aid of appropriate transformation and are numerically solved using the spectral collocation method. The present research model is concerned to study the stagnation point slippery flow, heat, and mass transfer analysis of a Casson fluid flow past an elastic surface with the impact of a magnetic field. The study focuses on the influences of Arrhenius activation energy, melting heat transfer, and heat source on heat and mass transfer behavior posed by Casson fluid. The magnitude of skin becomes lesser for larger values of slip parameter while the rate of mass transfer is enhanced via greater values of the destructive chemical reaction. Also, an excellent agreement is shown with previous studies for the limiting case.

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