Impact of ohmic heating on energy transport in double diffusive Oldroyd-B nanofluid flow induced by stretchable cylindrical surface

The most important and significant research topic in mechanical and industrial engineering is the fluid flow with heat transport by a stretched surface because of the numerous applications. The impact of heat transport on product quality can be noticed in the field of chemical engineering, polymer processing, glass fiber production, hot rolling, metal extrusion, production of paper, and drawing of plastic films and wires. In light of such foregoing applications, an attempt is made to model the thermal and solutal diffusion phenomena in Oldroyd-B nanofluid flow over a stretching cylinder by using Buongiorno's model and Cattaneo-Cristov theory. To explore the heat flow mechanism in the flow, the effects of heat source/sink with ohmic heating are also considered. Additionally, the influence of chemical reactions is used to investigate the solutal transport process in nanofluid flow. The mathematical formulation section of the manuscript depicts the mathematical modeling of momentum, heat, and mass diffusion equations. The effect of dimensionless physical constraints on the flow, temperature, and concentration distributions of Oldroyd-B nanofluid flow are investigated using the homotopy analysis method (HAM) in Wolfram Mathematica. In the results and discussion section, graphical findings are displayed and physically justified. A section of concluding remarks is added at the end of the text to emphasize the study's major findings.

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Burgers fluid flow in perspective of Buongiorno’s model with improved heat and mass flux theory for stretching cylinder

The European Physical Journal Applied Physics ◽

10.1051/epjap/2020200286 ◽

2020 ◽

Vol 92 (3) ◽

pp. 31101

Author(s):

Zahoor Iqbal ◽

Masood Khan ◽

Awais Ahmed

Keyword(s):

Diffusion Process ◽

Mathematical Formulation ◽

Thermal Relaxation ◽

Mass Diffusion ◽

Stretching Cylinder ◽

Discussion Section ◽

Buongiorno’S Model ◽

Homotopy Analysis ◽

Burgers Fluid ◽

Diffusion Phenomena

In this study, an effort is made to model the thermal conduction and mass diffusion phenomena in perspective of Buongiorno’s model and Cattaneo-Christov theory for 2D flow of magnetized Burgers nanofluid due to stretching cylinder. Moreover, the impacts of Joule heating and heat source are also included to investigate the heat flow mechanism. Additionally, mass diffusion process in flow of nanofluid is examined by employing the influence of chemical reaction. Mathematical modelling of momentum, heat and mass diffusion equations is carried out in mathematical formulation section of the manuscript. Homotopy analysis method (HAM) in Wolfram Mathematica is utilized to analyze the effects of physical dimensionless constants on flow, temperature and solutal distributions of Burgers nanofluid. Graphical results are depicted and physically justified in results and discussion section. At the end of the manuscript the section of closing remarks is also included to highlight the main findings of this study. It is revealed that an escalation in thermal relaxation time constant leads to ascend the temperature curves of nanofluid. Additionally, depreciation is assessed in mass diffusion process due to escalating amount of thermophoretic force constant.

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Numerical Simulation of Heat Mass Transfer Effects on MHD Flow of Williamson Nanofluid by a Stretching Surface with Thermal Conductivity and Variable Thickness

Coatings ◽

10.3390/coatings11060684 ◽

2021 ◽

Vol 11 (6) ◽

pp. 684

Author(s):

Saeed Islam ◽

Haroon Ur Rasheed ◽

Kottakkaran Sooppy Nisar ◽

Nawal A. Alshehri ◽

Mohammed Zakarya

Keyword(s):

Thermal Conductivity ◽

Boundary Layer ◽

Mass Transfer ◽

Differential Equations ◽

Variable Thickness ◽

Heat Mass Transfer ◽

Mathematical Formulation ◽

Stretching Surface ◽

Nanofluid Flow ◽

The Impact

The current analysis deals with radiative aspects of magnetohydrodynamic boundary layer flow with heat mass transfer features on electrically conductive Williamson nanofluid by a stretching surface. The impact of variable thickness and thermal conductivity characteristics in view of melting heat flow are examined. The mathematical formulation of Williamson nanofluid flow is based on boundary layer theory pioneered by Prandtl. The boundary layer nanofluid flow idea yields a constitutive flow laws of partial differential equations (PDEs) are made dimensionless and then reduce to ordinary nonlinear differential equations (ODEs) versus transformation technique. A built-in numerical algorithm bvp4c in Mathematica software is employed for nonlinear systems computation. Considerable features of dimensionless parameters are reviewed via graphical description. A comparison with another homotopic approach (HAM) as a limiting case and an excellent agreement perceived.

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Thermally and chemically reacted MHD Maxwell nanofluid flow past an inclined permeable stretching surface

Proceedings of the Institution of Mechanical Engineers Part E Journal of Process Mechanical Engineering ◽

10.1177/09544089211050715 ◽

2021 ◽

pp. 095440892110507

Author(s):

Amar B. Patil ◽

Vishwambhar S. Patil ◽

Pooja P. Humane ◽

Nalini S. Patil ◽

Govind R. Rajput

Keyword(s):

Differential Equations ◽

Energy Transport ◽

Stretching Surface ◽

Nanofluid Flow ◽

Linear Ordinary Differential Equations ◽

Maxwell Nanofluid ◽

Similarity Transformations ◽

Flow Past ◽

Chemically Reacting ◽

The Impact

The present work deals with chemically reacting unsteady magnetohydrodynamic Maxwell nanofluid flow past an inclined permeable stretching surface embedded in a porous medium with thermal radiation. The formulated governing partial differential equations conveying the flow model of Maxwell with Buongiorno modeled nanofluid is transformed into the system of highly non-linear ordinary differential equations via suitable similarity transformations; those equations are transmuted into an initial value problem and then solved numerically by a shooting approach with Runge–-Kutta fourth-order schema. To obtain the physical insight of the flow situation, the influence of associated parameters on the velocity, temperature, and concentration profiles is sketched graphically with the aid of MATLAB software. Furthermore, engineering quantities of interest are interpreted graphically. The computed numerical results are compared to estimate the validity of the achieved results; it has been found out that the computed results are highly accurate. The impact of the Maxwell parameter and inclination angle of the sheet on the velocity field is observed in decaying. Both thermal and solutal energy transport are progressive in nature as the Maxwell parameter and thermophoresis parameter grows, and a reverse trend is observed for Prandtl number.

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Unsteady Three-Dimensional MHD Nanofluid Flow Over a Stretching Sheet with Variable Wall Thickness and Slip Effects

International Journal of Applied Mechanics and Engineering ◽

10.2478/ijame-2019-0044 ◽

2019 ◽

Vol 24 (3) ◽

pp. 709-724

Author(s):

G. Vinod Kumar ◽

S.V.K. Varma ◽

R.V.M.S.S.K. Kumar

Keyword(s):

Boundary Layer ◽

Wall Thickness ◽

Stretching Sheet ◽

Three Dimensional ◽

Nanofluid Flow ◽

Buongiorno’S Model ◽

Slip Boundary ◽

Variable Wall Thickness ◽

Variable Wall ◽

The Impact

Abstract The stretching sheets with variable thickness may occur in engineering applications more frequently than a flat sheet. Due to its various applications, in the present analysis we considered a three dimensional unsteady MHD nanofluid flow over a stretching sheet with a variable wall thickness in a porous medium. The effects of radiation, viscous dissipation and slip boundary conditions are considered. Buongiorno’s model is incorporated to study the combined effects of thermophoresis and Brownian motion. The dimensionless governing equations are solved by using MATLAB bvp4c package. The impact of various important flow parameters is presented and analysed through graphs and tables. It is interesting to note that all the three boundary layer thicknesses are diminished by slip parameters. Further, the unsteady parameter decreases the hydromagnetic boundary layer thickness.

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Nonlocal heat flux effects on temperature evolution of the solar atmosphere

Astronomy and Astrophysics ◽

10.1051/0004-6361/201730580 ◽

2018 ◽

Vol 615 ◽

pp. A32

Author(s):

S. S. A. Silva ◽

J. C. Santos ◽

J. Büchner ◽

M. V. Alves

Keyword(s):

Magnetic Field ◽

Heat Flux ◽

Solar Corona ◽

Heat Transport ◽

Transition Region ◽

Solar Atmosphere ◽

Energy Transport ◽

Flux Model ◽

The Impact ◽

Heat Flux Model

Context. Heat flux is one of the main energy transport mechanisms in the weakly collisional plasma of the solar corona. There, rare binary collisions let hot electrons travel over long distances and influence other regions along magnetic field lines. Thus, the fully collisional heat flux models might not describe transport well enough since they consider only the local contribution of electrons. The heat flux in weakly collisional plasmas at high temperatures with large mean free paths has to consider the nonlocality of the energy transport in the frame of nonlocal models in order to treat energy balance in the solar atmosphere properly. Aims. We investigate the impact of nonlocal heat flux on the thermal evolution and dynamics of the solar atmosphere by implementing a nonlocal heat flux model in a 3D magnetohydrodynamic simulation of the solar corona. Methods. We simulate the evolution of solar coronal plasma and magnetic fields considering both a local collision dominated and a nonlocal heat flux model. The initial magnetic field is obtained by a potential extrapolation of the observed line-of-sight magnetic field of AR11226. The system is perturbed by moving the plasma at the photosphere. We compared the simulated evolution of the solar atmosphere in its dependence on the heat flux model. Results. The main differences for the average temperature profiles were found in the upper chromosphere/transition region. In the nonlocal heat transport model case, thermal energy is transported more efficiently to the upper chromosphere and lower transition region and leads to an earlier heating of the lower atmosphere. As a consequence, the structure of the solar atmosphere is affected with the nonlocal simulations producing on average a smoother temperature profile and the transition region placed about 500 km higher. Using a nonlocal heat flux also leads to two times higher temperatures in some of the regions in the lower corona. Conclusions. The results of our 3D MHD simulations considering nonlocal heat transport supports the previous results of simpler 1D two-fluid simulations. They demonstrated that it is important to consider a nonlocal formulation for the heat flux when there is a strong energy deposit, like the one observed during flares, in the solar corona.

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The Consequences of Excessive Chemicalization on Fruits Quality

Revista de Chimie ◽

10.37358/rc.18.6.6315 ◽

2018 ◽

Vol 69 (6) ◽

pp. 1303-1308 ◽

Cited By ~ 3

Author(s):

Manuel Alexandru Gitea ◽

Simona Bungau ◽

Daniela Gitea ◽

Lavinia Purza ◽

Sebastian Nemeth ◽

...

Keyword(s):

Environmental Protection ◽

Pesticide Residues ◽

Chemical Engineering ◽

Agricultural Productivity ◽

Fruit Trees ◽

Pesticide Treatment ◽

Intensive Intervention ◽

Optimal Efficiency ◽

The Impact ◽

Intensive System

Chemistry in agriculture has been considered for several decades a formula synonymous with progress and development, as chemical engineering, mechanization, irrigation, modern agro-technical processes have contributed to a substantial increase in production. At present, the use of pesticides to increase agricultural productivity is considered to be a global hazard to the environment. This study examines changes in tree tolerance for major diseases and pests, disease and pest behavior, and the changes that occur in the recommended pesticide treatment. The researches were carried out on different species of fruit trees (apple, plum, and almond), cultivated in an intensive system, in five orchards located in Bihor county. The behavior of each species, as well as the behavior of different varieties with respect to tolerance to major diseases and pests, have been observed over the last 5 years (2013-2017). In addition, pesticide residues were monitored from all crops of apple, plum and almond. During 2015-2017, from March to May, the diseases were more virulent, requiring intensive intervention with systemic and contact fungicide combinations to achieve optimal efficiency; this fact has been correlated with the increase in the number of samples containing pesticide residues. This perspective allows an ecological remodeling of current progress in orchard development, including all aspects of environmental protection and the impact on population2 s health.

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Nanofluid flow containing carbon nanotubes with quartic autocatalytic chemical reaction and Thompson and Troian slip at the boundary

Scientific Reports ◽

10.1038/s41598-020-74855-7 ◽

2020 ◽

Vol 10 (1) ◽

Cited By ~ 1

Author(s):

Muhammad Ramzan ◽

Jae Dong Chung ◽

Seifedine Kadry ◽

Yu-Ming Chu ◽

Muhammad Akhtar

Keyword(s):

Mathematical Model ◽

Carbon Nanotubes ◽

Drag Force ◽

Chemical Reaction ◽

Slip Velocity ◽

Volume Fraction ◽

Surface Drag ◽

Nanofluid Flow ◽

Velocity Parameter ◽

The Impact

Abstract A mathematical model is envisioned to discourse the impact of Thompson and Troian slip boundary in the carbon nanotubes suspended nanofluid flow near a stagnation point along an expanding/contracting surface. The water is considered as a base fluid and both types of carbon nanotubes i.e., single-wall (SWCNTs) and multi-wall (MWCNTs) are considered. The flow is taken in a Dacry-Forchheimer porous media amalgamated with quartic autocatalysis chemical reaction. Additional impacts added to the novelty of the mathematical model are the heat generation/absorption and buoyancy effect. The dimensionless variables led the envisaged mathematical model to a physical problem. The numerical solution is then found by engaging MATLAB built-in bvp4c function for non-dimensional velocity, temperature, and homogeneous-heterogeneous reactions. The validation of the proposed mathematical model is ascertained by comparing it with a published article in limiting case. An excellent consensus is accomplished in this regard. The behavior of numerous dimensionless flow variables including solid volume fraction, inertia coefficient, velocity ratio parameter, porosity parameter, slip velocity parameter, magnetic parameter, Schmidt number, and strength of homogeneous/heterogeneous reaction parameters are portrayed via graphical illustrations. Computational iterations for surface drag force are tabulated to analyze the impacts at the stretched surface. It is witnessed that the slip velocity parameter enhances the fluid stream velocity and diminishes the surface drag force. Furthermore, the concentration of the nanofluid flow is augmented for higher estimates of quartic autocatalysis chemical.

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Numerical treatment of time dependent magnetohydrodynamic nanofluid flow of mass and heat transport subject to chemical reaction and heat source

Alexandria Engineering Journal ◽

10.1016/j.aej.2021.07.030 ◽

2021 ◽

Author(s):

Yun-Xiang Li ◽

S.R. Mishra ◽

P.K. Pattnaik ◽

S. Baag ◽

Yong-Min Li ◽

...

Keyword(s):

Heat Source ◽

Heat Transport ◽

Chemical Reaction ◽

Time Dependent ◽

Numerical Treatment ◽

Nanofluid Flow

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In Vitro Gastrointestinal Digestion Impact on the Bioaccessibility and Antioxidant Capacity of Bioactive Compounds from Tomato Flours Obtained after Conventional and Ohmic Heating Extraction

Foods ◽

10.3390/foods10030554 ◽

2021 ◽

Vol 10 (3) ◽

pp. 554

Author(s):

Marta C. Coelho ◽

Tânia B. Ribeiro ◽

Carla Oliveira ◽

Patricia Batista ◽

Pedro Castro ◽

...

Keyword(s):

Gastrointestinal Tract ◽

Phenolic Compounds ◽

Antioxidant Capacity ◽

Bioactive Compounds ◽

Solid Fraction ◽

Ohmic Heating ◽

Coumaric Acid ◽

Insoluble Dietary Fiber ◽

The Impact

In times of pandemic and when sustainability is in vogue, the use of byproducts, such as fiber-rich tomato byproducts, can be an asset. There are still no studies on the impact of extraction methodologies and the gastrointestinal tract action on bioactive properties. Thus, this study used a solid fraction obtained after the conventional method (SFCONV) and a solid fraction after the ohmic method (SFOH) to analyze the effect of the gastrointestinal tract on bioactive compounds (BC) and bioactivities. Results showed that the SFOH presents higher total fiber than SFCONV samples, 62.47 ± 1.24–59.06 ± 0.67 g/100 g DW, respectively. Both flours present high amounts of resistant protein, representing between 11 and 16% of insoluble dietary fiber. Furthermore, concerning the total and bound phenolic compounds, the related antioxidant activity measured by 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical cation decolorization assay presented significantly higher values for SFCONV than SFOH samples (p < 0.05). The main phenolic compounds identified in the two flours were gallic acid, rutin, and p-coumaric acid, and carotenoids were lycopene, phytofluene, and lutein, all known as health promoters. Despite the higher initial values of SFCONV polyphenols and carotenoids, these BCs’ OH flours were more bioaccessible and presented more antioxidant capacity than SFCONV flours, throughout the simulated gastrointestinal tract. These results confirm the potential of ohmic heating to modify the bioaccessibility of tomato BC, enhancing their concentrations and improving their antioxidant capacity.

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