scholarly journals Entropy generation and dissipative heat transfer analysis of mixed convective hydromagnetic flow of a Casson nanofluid with thermal radiation and Hall current

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
A. Sahoo ◽  
R. Nandkeolyar
Keyword(s):  
Temperature Distribution ◽  
Differential Equations ◽  
Ordinary Differential Equations ◽  
Entropy Generation ◽  
Ohmic Heating ◽  
Heat Transfer Analysis ◽  
Bejan Number ◽  
Casson Nanofluid ◽  
Highly Nonlinear ◽  
Physical Quantities

AbstractThe present article provides a detailed analysis of entropy generation on the unsteady three-dimensional incompressible and electrically conducting magnetohydrodynamic flow of a Casson nanofluid under the influence of mixed convection, radiation, viscous dissipation, Brownian motion, Ohmic heating, thermophoresis and heat generation. At first, similarity transformation is used to transform the governing nonlinear coupled partial differential equations into nonlinear coupled ordinary differential equations, and then the resulting highly nonlinear coupled ordinary differential equations are numerically solved by the utilization of spectral quasi-linearization method. Moreover, the effects of pertinent flow parameters on velocity distribution, temperature distribution, concentration distribution, entropy generation and Bejan number are depicted prominently through various graphs and tables. It can be analyzed from the graphs that the Casson parameter acts as an assisting parameter towards the temperature distribution in the absence of viscous and Joule dissipations, while it has an adverse effect on temperature under the impacts of viscous and Joule dissipations. On the contrary, entropy generation increases significantly for larger Brinkman number, diffusive variable and concentration ratio parameter, whereas the reverse effects of these parameters on Bejan number are examined. Apart from this, the numerical values of some physical quantities such as skin friction coefficients in x and z directions, local Nusselt number and Sherwood number for the variation of the values of pertinent parameters are displayed in tabular forms. A quadratic multiple regression analysis for these physical quantities has also been carried out to improve the present model’s effectiveness in various industrial and engineering areas. Furthermore, an appropriate agreement is obtained on comparing the present results with previously published results.

scholarly journals Entropy Generation and Heat Transfer Analysis in MHD Unsteady Rotating Flow for Aqueous Suspensions of Carbon Nanotubes with Nonlinear Thermal Radiation and Viscous Dissipation Effect

Entropy ◽  
2019 ◽  
Vol 21 (5) ◽  
pp. 492 ◽  
Author(s):  
Muhammad Jawad ◽  
Zahir Shah ◽  
Aurungzeb Khan ◽  
Waris Khan ◽  
Poom Kumam ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Carbon Nanotubes ◽  
Differential Equations ◽  
Viscous Dissipation ◽  
Entropy Generation ◽  
Heat Transfer Analysis ◽  
Shrinking Sheet ◽  
Bejan Number ◽  
Nanofluid Flow ◽  
The Impact

The impact of nonlinear thermal radiations rotating with the augmentation of heat transfer flow of time-dependent single-walled carbon nanotubes is investigated. Nanofluid flow is induced by a shrinking sheet within the rotating system. The impact of viscous dissipation is taken into account. Nanofluid flow is assumed to be electrically conducting. Similarity transformations are applied to transform PDEs (partial differential equations) into ODEs (ordinary differential equations). Transformed equations are solved by the homotopy analysis method (HAM). The radiative source term is involved in the energy equation. For entropy generation, the second law of thermodynamics is applied. The Bejan number represents the current investigation of non-dimensional entropy generation due to heat transfer and fluid friction. The results obtained indicate that the thickness of the boundary layer decreases for greater values of the rotation parameter. Moreover, the unsteadiness parameter decreases the temperature profile and increases the velocity field. Skin friction and the Nusselt number are also physically and numerically analyzed.

Entropy generation and heat transfer analysis for ferrofluid flow between two rotating disks with variable conductivity

2021 ◽  
pp. 095440622199118
Author(s):  
Anupam Bhandari
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Differential Equations ◽  
Entropy Generation ◽  
Heat Transfer Analysis ◽  
Entropy Generation Rate ◽  
Geometrical Parameters ◽  
Rotating Disks ◽  
Coupled Differential Equations ◽  
Lower Disk

Present model analyze the flow and heat transfer of water-based carbon nanotubes (CNTs) [Formula: see text] ferrofluid flow between two radially stretchable rotating disks in the presence of a uniform magnetic field. A study for entropy generation analysis is carried out to measure the irreversibility of the system. Using similarity transformation, the governing equations in the model are transformed into a set of nonlinear coupled differential equations in non-dimensional form. The nonlinear coupled differential equations are solved numerically through the finite element method. Variable viscosity, variable thermal conductivity, thermal radiation, and volume concentration have a crucial role in heat transfer enhancement. The results for the entropy generation rate, velocity distributions, and temperature distribution are graphically presented in the presence of physical and geometrical parameters of the flow. Increasing the values of ferromagnetic interaction number, Reynolds number, and temperature-dependent viscosity enhances the skin friction coefficients on the surface and wall of the lower disk. The local heat transfer rate near the lower disk is reduced in the presence of Harman number, Reynolds number, and Prandtl number. The ferrohydrodynamic flow between two rotating disks might be useful to optimize the use of hybrid nanofluid for liquid seals in rotating machinery.

Effects of chemical reaction and activation energy on a Carreau nanoliquid past a permeable surface under zero mass flux conditions

2019 ◽  
Vol 234 (1-2) ◽  
pp. 47-57
Author(s):  
GK Ramesh ◽  
K Ganesh Kumar ◽  
Ali J Chamkha ◽  
Rama Subba Reddy Gorla
Keyword(s):  
Activation Energy ◽  
Differential Equations ◽  
Ordinary Differential Equations ◽  
Chemical Reaction ◽  
Permeable Surface ◽  
Concentration Gradients ◽  
Zero Mass ◽  
Temperature Impact ◽  
Fifth Order ◽  
Physical Quantities

Arrhenius condition has been broadly utilized as a model of the temperature impact on the rate compound responses and organic procedure. Hence, our aim of this article is to examine the effects of chemical reaction and activation energy on a Carreau nanoliquid in a permeable surface. For thermal and mass transport curiosities, the cumulative upgrade of convective type condition and zero mass transition have been considered. The overseeing sets of partial differential equations are rendered into coupled nonlinear ordinary differential equations. The arrangement of the subsequent ordinary differential equations is acquired with the assistance of the Runge-Kutta-Fehlberg-fourth-fifth order (RKF-45) procedure. The influence of relevant parameters and physical quantities is investigated. The results show that the presence of reaction rate and energy activation term decelerates the temperature and concentration gradients.

Numerical model of the steam pipeline with thermal insulation

2019 ◽  
Vol 30 (5) ◽  
pp. 2237-2253 ◽  
Author(s):  
Karol Kaczmarski
Keyword(s):  
Temperature Distribution ◽  
Numerical Model ◽  
Differential Equations ◽  
Ordinary Differential Equations ◽  
Outer Surface ◽  
Transient Temperature ◽  
Content Type ◽  
First Order ◽  
Steam Pipeline ◽  
Pipeline Wall

Purpose The purpose of this paper is to develop a numerical model of a steam pipeline connecting a boiler with a turbine, with an insulated outer surface. The temperature distribution inside the pipeline wall was compared when was perfectly insulated and when used real insulation on the outside surface. Design/methodology/approach The transient temperature, pressure and velocity of steam in the pipeline were determined using a proposed numerical model with distributed parameters. To calculate the transient temperature of the steam and pipeline wall the finite volume method was used. The energy conservation equations were written for all control area around all the nodes. The heat balance equations are a system of first-order ordinary differential equations with respect to time. The Runge–Kutta method of the fourth-order was used to solve the system of ordinary differential equations of the first-order. Findings The temperature distribution in the pipeline wall and the temperature distribution in wall insulation were presented. Also, the temperature of the steam and pipeline wall as a function of insulation thickness was calculated. Based on the results obtained by the proposed numerical model, thermal stresses at the inner and outer surface of the component were determined. To assess the accuracy of the proposed model, the results were compared to the analytical solution for the steady state. Originality/value The paper presents the results obtained from calculations using a numerical model of the steam pipeline with the actual insulation on the outer surface.

scholarly journals Entropy Generation in Couette Flow Through a Deformable Porous Channel

2019 ◽  
Vol 4 (2) ◽  
pp. 575-590 ◽  
Author(s):  
G. Gopi Krishna ◽  
S. Sreenadh ◽  
A.N.S. Srinivas
Keyword(s):  
Porous Medium ◽  
Temperature Distribution ◽  
Couette Flow ◽  
Entropy Generation ◽  
Volume Fraction ◽  
Fluid Velocity ◽  
Porous Channel ◽  
Injection Velocity ◽  
Bejan Number ◽  
Parallel Plates

AbstractThe present study examines the entropy generation on Couette flow of a viscous fluid in parallel plates filled with deformable porous medium. The fluid is injected into the porous channel perpendicular to the lower wall with a constant velocity and is sucked out of the upper wall with same velocity .The coupled phenomenon of the fluid flow and solid deformation in the porous medium is taken in to consideration. The exact expressions for the velocity of fluid, solid displacement and temperature distribution are found analytically. The effect of pertinent parameters on the fluid velocity, solid displacement and temperature profiles are discussed in detail. In the deformable porous layer, it is noticed that the velocity of fluid, solid displacement and temperature distribution are decreases with increasing the suction/injection velocity parameter. The results obtained for the present flow characteristic reveal several interesting behaviors that warrant further study on the deformable porous media. Furthermore, the significance of drag and the volume fraction on entropy generation number and Bejan number are discussed with the help of graphs.

scholarly journals Darcy-Forchheimer hybrid nanofluid flow over a stretching curved surface with heat and mass transfer

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0249434
Author(s):  
Anwar Saeed ◽  
Wajdi Alghamdi ◽  
Safyan Mukhtar ◽  
Syed Imad Ali Shah ◽  
Poom Kumam ◽  
...  
Keyword(s):  
Differential Equations ◽  
Ordinary Differential Equations ◽  
Volume Fraction ◽  
Curved Surface ◽  
Hybrid Nanofluid ◽  
Porous Space ◽  
Highly Nonlinear ◽  
Homotopy Analysis ◽  
Curvature Parameter ◽  
Swcnts And Mwcnts

The present article provides a detailed analysis of the Darcy Forchheimer flow of hybrid nanoliquid past an exponentially extending curved surface. In the porous space, the viscous fluid is expressed by Darcy-Forchheimer. The cylindrical shaped carbon nanotubes (SWCNTs and MWCNTs) and Fe3O4 (iron oxide) are used to synthesize hybrid nanofluid. At first, the appropriate similarity transformation is used to convert the modeled nonlinear coupled partial differential equations into nonlinear coupled ordinary differential equations. Then the resulting highly nonlinear coupled ordinary differential equations are analytically solved by the utilization of the “Homotopy analysis method” (HAM) method. The influence of sundry flow factors on velocity, temperature, and concentration profile are sketched and briefly discussed. The enhancement in both volume fraction parameter and curvature parameter k results in raises of the velocity profile. The uses of both Fe3O4 and CNTs nanoparticles are expressively improving the thermophysical properties of the base fluid. Apart from this, the numerical values of some physical quantities such as skin friction coefficients, local Nusselt number, and Sherwood number for the variation of the values of pertinent parameters are displayed in tabular forms. The obtained results show that the hybrid nanofluid enhances the heat transfer rate 2.21%, 2.1%, and 2.3% using the MWCNTs, SWCNTs, and Fe3O4 nanomaterials.

scholarly journals Aspects of Chemical Entropy Generation in Flow of Casson Nanofluid between Radiative Stretching Disks

Entropy ◽  
2020 ◽  
Vol 22 (5) ◽  
pp. 495 ◽  
Author(s):  
Nargis Khan ◽  
Iram Riaz ◽  
Muhammad Sadiq Hashmi ◽  
Saed A. Musmar ◽  
Sami Ullah Khan ◽  
...  
Keyword(s):  
Entropy Generation ◽  
Fluid Velocity ◽  
Axisymmetric Flow ◽  
Casson Fluid ◽  
Physical Parameters ◽  
Bejan Number ◽  
Axial Component ◽  
Radiation Chemical ◽  
Casson Nanofluid ◽  
The Impact

The appropriate utilization of entropy generation may provoke dipping losses in the available energy of nanofluid flow. The effects of chemical entropy generation in axisymmetric flow of Casson nanofluid between radiative stretching disks in the presence of thermal radiation, chemical reaction, and heat absorption/generation features have been mathematically modeled and simulated via interaction of slip boundary conditions. Shooting method has been employed to numerically solve dimensionless form of the governing equations, including expressions referring to entropy generation. The impacts of the physical parameters on fluid velocity components, temperature and concentration profiles, and entropy generation number are presented. Simulation results revealed that axial component of velocity decreases with variation of Casson fluid parameter. A declining variation in Bejan number was noticed with increment of Casson fluid constant. Moreover, a progressive variation in Bejan number resulted due to the impact of Prandtl number and stretching ratio constant.

scholarly journals Consequences of Soret–Dufour Effects, Thermal Radiation, and Binary Chemical Reaction on Darcy Forchheimer Flow of Nanofluids

Symmetry ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1421 ◽  
Author(s):  
Ghulam Rasool ◽  
Anum Shafiq ◽  
Dumitru Baleanu
Keyword(s):  
Temperature Distribution ◽  
Velocity Field ◽  
Thermal Radiation ◽  
Chemical Reaction ◽  
Concentration Distribution ◽  
Tabular Data ◽  
Data Form ◽  
Highly Nonlinear ◽  
Physical Quantities ◽  
Forchheimer Flow

This research article aims to investigate the consequences of binary chemical reaction, thermal radiation, and Soret–Dufour effects on a steady incompressible Darcy–Forchheimer flow of nanofluids. Stretching surface is assumed to drive the fluid along positive horizontal direction. Brownian motion, and the Thermophoresis are accounted in particular. The governing highly nonlinear system of problems which are advanced version of Navier–Stokes equations are transformed into ordinary differential equations (ODEs) using appropriately adjusted transformations invoking symmetric property of the independent variables. The numerical approach using RK45 in connection with shooting technique is adopted to solve the final equations. Graphical approach is used to interpret the results and the values of important physical quantities are given in tabular data form. Velocity field, temperature distribution and concentration distribution are graphically analyzed for variation in respective fluid parameters. Furthermore, density graphs and stream lines are sketched for the present model. The outputs indicate a rise of temperature field in connection with thermal radiation parameter. A clear decline is noticed in velocity field for elevated values of Forchheimer number and porosity factor. The Dufour effect anticipates a rising factor for temperature distribution and the same is noticed for concentration distribution in lieu of Soret effect. Thermal radiation and binary chemical reaction has strong impact on heat transport mechanism. The results for physical quantities such as skin friction, heat and mass flux rates are given in tabular data form in last section of this study.

scholarly journals Entropy Generation and Consequences of Binary Chemical Reaction on MHD Darcy–Forchheimer Williamson Nanofluid Flow Over Non-Linearly Stretching Surface

Entropy ◽  
2019 ◽  
Vol 22 (1) ◽  
pp. 18 ◽  
Author(s):  
Ghulam Rasool ◽  
Ting Zhang ◽  
Ali J. Chamkha ◽  
Anum Shafiq ◽  
Iskander Tlili ◽  
...  
Keyword(s):  
Entropy Generation ◽  
Second Law Of Thermodynamics ◽  
Magnetic Reynolds Number ◽  
Random Motion ◽  
Weissenberg Number ◽  
Brownian Diffusion ◽  
Bejan Number ◽  
Nanofluid Flow ◽  
Highly Nonlinear ◽  
Buongiorno Model

The current article aims to present a numerical analysis of MHD Williamson nanofluid flow maintained to flow through porous medium bounded by a non-linearly stretching flat surface. The second law of thermodynamics was applied to analyze the fluid flow, heat and mass transport as well as the aspects of entropy generation using Buongiorno model. Thermophoresis and Brownian diffusion is considered which appears due to the concentration and random motion of nanoparticles in base fluid, respectively. Uniform magnetic effect is induced but the assumption of tiny magnetic Reynolds number results in zero magnetic induction. The governing equations (PDEs) are transformed into ordinary differential equations (ODEs) using appropriately adjusted transformations. The numerical method is used for solving the so-formulated highly nonlinear problem. The graphical presentation of results highlights that the heat flux receives enhancement for augmented Brownian diffusion. The Bejan number is found to be increasing with a larger Weissenberg number. The tabulated results for skin-friction, Nusselt number and Sherwood number are given. A decent agreement is noted in the results when compared with previously published literature on Williamson nanofluids.

scholarly journals On Mixed Convection Squeezing Flow of Nanofluids

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3138 ◽  
Author(s):  
Sheikh Irfan Ullah Khan ◽  
Ebraheem Alzahrani ◽  
Umar Khan ◽  
Noreena Zeb ◽  
Anwar Zeb
Keyword(s):  
Nonlinear System ◽  
Differential Equations ◽  
Mixed Convection ◽  
Ordinary Differential Equations ◽  
Volume Fraction ◽  
Squeezing Flow ◽  
Physical Parameters ◽  
Gamma Alumina ◽  
Highly Nonlinear ◽  
The Impact

In this article, the impact of effective Prandtl number model on 3D incompressible flow in a rotating channel is proposed under the influence of mixed convection. The coupled nonlinear system of partial differential equations is decomposed into a highly nonlinear system of ordinary differential equations with aid of suitable similarity transforms. Then, the solution of a nonlinear system of ordinary differential equations is obtained numerically by using Runge–Kutta–Fehlberg (RKF) method. Furthermore, the surface drag force C f and the rate of heat transfer N u are portrayed numerically. The effects of different emerging physical parameters such as Hartmann number (M), Reynold’s number (Re), squeezing parameter ( β ), mixed convection parameter λ , and volume fraction ( φ ) are also incorporated graphically for γ — alumina. Due to the higher viscosity and thermal conductivity ethylene-based nanofluids, it is observed to be an effective common base fluid as compared to water. These observations portrayed the temperature of gamma-alumina ethylene-based nanofluids rising on gamma-alumina water based nanofluids.

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