MHD and nonlinear thermal radiation effects on hybrid nanofluid past a wedge with heat source and entropy generation

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Fazle Mabood ◽  
Anum Shafiq ◽  
Waqar Ahmed Khan ◽  
Irfan Anjum Badruddin
Keyword(s):  
Heat Transfer ◽  
Differential Equations ◽  
Heat Source ◽  
Thermal Radiation ◽  
Entropy Generation ◽  
Entropy Generation Rate ◽  
Design Parameters ◽  
Hybrid Nanofluid ◽  
Nonlinear Thermal Radiation ◽  
Content Type

Purpose This study aims to investigate the irreversibility associated with the Fe3O4–Co/kerosene hybrid-nanofluid past a wedge with nonlinear radiation and heat source. Design/methodology/approach This study reports the numerical analysis of the hybrid nanofluid model under the implications of the heat source and magnetic field over a static and moving wedge with slips. The second law of thermodynamics is applied with nonlinear thermal radiation. The system that comprises differential equations of partial derivatives is remodeled into the system of differential equations via similarity transformations and then solved through the Runge–Kutta–Fehlberg with shooting technique. The physical parameters, which emerges from the derived system, are discussed in graphical formats. Excellent proficiency in the numerical process is analyzed by comparing the results with available literature in limiting scenarios. Findings The significant outcomes of the current investigation are that the velocity field uplifts for higher velocity slip and magnetic strength. Further, the heat transfer rate is reduced with the incremental values of the Eckert number, while it uplifts with thermal slip and radiation parameters. An increase in Brinkmann’s number uplifts the entropy generation rate, while that peters out the Bejan number. The results of this study are of importance involving in the assessment of the effect of some important design parameters on heat transfer and, consequently, on the optimization of industrial processes. Originality/value This study is original work that reports the hybrid nanofluid model of Fe3O4–Co/kerosene.

scholarly journals Free convection heat transfer and entropy generation analysis of water-Fe3O4/CNT hybrid nanofluid in a concentric annulus

2019 ◽  
Vol 29 (3) ◽  
pp. 915-934 ◽  
Author(s):  
Amin Shahsavar ◽  
Pouyan Talebizadeh Sardari ◽  
D. Toghraie
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Rayleigh Number ◽  
Entropy Generation ◽  
Average Nusselt Number ◽  
Generation Rate ◽  
Entropy Generation Rate ◽  
Hybrid Nanofluid ◽  
Content Type ◽  
Thermal Entropy

Purpose This paper aims to numerically investigate the heat transfer and entropy generation characteristics of water-based hybrid nanofluid in natural convection flow inside a concentric horizontal annulus. Design/methodology/approach The hybrid nanofluid is prepared by suspending tetramethylammonium hydroxide-coated Fe3O4 (magnetite) nanoparticles and gum arabic (GA)-coated carbon nanotubes (CNTs) in water. The effects of nanoparticle volume concentration and Rayleigh number on the streamlines, isotherms, average Nusselt number and the thermal, frictional and total entropy generation rates are investigated comprehensively. Findings Results show the advantageous effect of hybrid nanofluid on the average Nusselt number. Furthermore, the study of entropy generation shows the increment of both frictional and thermal entropy generation rates by increasing Fe3O4 and CNT concentrations at various Rayleigh numbers. Increasing Rayleigh number from 103 to 105, at Fe3O4 concentration of 0.9 per cent and CNT concentration of 1.35 per cent, increases the average Nusselt number, thermal entropy generation rate and frictional entropy generation rate by 224.95, 224.65 and 155.25 per cent, respectively. Moreover, increasing the Fe3O4 concentration from 0.5 to 0.9 per cent, at Rayleigh number of 105 and CNT concentration of 1.35 per cent, intensifies the average Nusselt number, thermal entropy generation rate and frictional entropy generation rate by 18.36, 22.78 and 72.7 per cent, respectively. Originality/value To the best knowledge of the authors, there are not any archival publications considering the detailed behaviour of the natural convective heat transfer and entropy generation of hybrid nanofluid in a concentric annulus.

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.

scholarly journals MHD stagnation-point flow and heat transfer past a stretching/shrinking sheet in a hybrid nanofluid with induced magnetic field

2019 ◽  
Vol 30 (3) ◽  
pp. 1345-1364 ◽  
Author(s):  
Mohamad Mustaqim Junoh ◽  
Fadzilah Md Ali ◽  
Norihan Md Arifin ◽  
Norfifah Bachok ◽  
Ioan Pop
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Differential Equations ◽  
Stagnation Point ◽  
Nonlinear Partial Differential Equations ◽  
Stagnation Point Flow ◽  
Shrinking Sheet ◽  
Hybrid Nanofluid ◽  
Induced Magnetic Field ◽  
Content Type

Purpose The purpose of this paper is to investigate the steady magnetohydrodynamics (MHD) boundary layer stagnation-point flow of an incompressible, viscous and electrically conducting fluid past a stretching/shrinking sheet with the effect of induced magnetic field. Design/methodology/approach The governing nonlinear partial differential equations are transformed into a system of nonlinear ordinary differential equations via the similarity transformations before they are solved numerically using the “bvp4c” function in MATLAB. Findings It is found that there exist non-unique solutions, namely, dual solutions for a certain range of the stretching/shrinking parameters. The results from the stability analysis showed that the first solution (upper branch) is stable and valid physically, while the second solution (lower branch) is unstable. Practical implications This problem is important in the heat transfer field such as electronic cooling, engine cooling, generator cooling, welding, nuclear system cooling, lubrication, thermal storage, solar heating, cooling and heating in buildings, biomedical, drug reduction, heat pipe, space aircrafts and ships with better efficiency than that of nanofluids applicability. The results obtained are very useful for researchers to determine which solution is physically stable, whereby, mathematically more than one solution exist. Originality/value The present results are new and original for the problem of MHD stagnation-point flow over a stretching/shrinking sheet in a hybrid nanofluid, with the effect of induced magnetic field.

Cross flow and heat transfer past a permeable stretching/shrinking sheet in a hybrid nanofluid

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Natalia C. Roşca ◽  
Alin V. Roşca ◽  
Amin Jafarimoghaddam ◽  
Ioan Pop
Keyword(s):  
Heat Transfer ◽  
Differential Equations ◽  
Cross Flow ◽  
Porous Wall ◽  
Shrinking Sheet ◽  
Hybrid Nanofluid ◽  
Lower Branch ◽  
Content Type ◽  
Flow And Heat Transfer ◽  
Branch Solution

Purpose The purpose of this paper is to study the laminar boundary layer cross flow and heat transfer on a rotational stagnation-point flow over either a stretching or shrinking porous wall submerged in hybrid nanofluids. The involved boundary layers are of stream-wise type with stretching/shrinking process along the surface. Design/methodology/approach Using appropriate similarity variables the partial differential equations are reduced to ordinary (similarity) differential equations. The reduced system of equations is solved analytically (by high-order perturbed field propagation for small to moderate stretching/shrinking parameter and low-order perturbation for large stretching/shrinking parameter) and numerically using the function bvp4c from MATLAB for different values of the governing parameters. Findings It was found that the basic similarity equations admit dual (upper and lower branch) solutions for both stretching/shrinking surfaces. Moreover, performing a linear stability analysis, it was confirmed that the upper branch solution is realistic (physically realizable), while the lower branch solution is not physically realizable in practice. These dual solutions will be studied in the present paper. Originality/value The authors believe that all numerical results are new and original and have not been published before for the present problem.

Entropy generation and second law analysis of pulsed impinging jet

2015 ◽  
Vol 25 (5) ◽  
pp. 1089-1106 ◽  
Author(s):  
Kazem Esmailpour ◽  
Behnam Bozorgmehr ◽  
Seyed Mostafa Hosseinalipour ◽  
Arun S. Mujumdar
Keyword(s):  
Heat Transfer ◽  
Temperature Field ◽  
Entropy Generation ◽  
Impinging Jet ◽  
Entropy Generation Rate ◽  
Second Law ◽  
Pulsation Frequency ◽  
Content Type ◽  
Thermal Entropy ◽  
Plate Distance

Purpose – The purpose of this paper is to examine entropy generation rate in the flow and temperature field due pulsed impinging jet on to a flat plate. Heat transfer of pulsed impinging jets has been investigated by many researchers. Entropy generation is one of the parameters related to the second law of thermodynamics which must be analyzed in processes with heat transfer and fluid flow in order to design efficient systems. Effect of velocity profile parameters and various nozzle to plate distances on viscous and thermal entropy generation are investigated. Design/methodology/approach – In this study, the flow and temperature field of a pulsed turbulent impinging jet are simulated numerically by the finite volume method with appropriate boundary conditions. Then, flow and temperature results are used to calculate the rate of entropy generation due to heat transfer and viscous dissipation. Findings – Results show that maximum viscous and thermal entropy generation occurs in the lowest nozzle to plate distance and entropy generation decreases as the nozzle to plate distance increases. Entropy generation in the two early phase of a period in the most frequencies is more than steady state whereas a completely opposite behavior happens in the two latter phase. Increase in the pulsation frequency and amplitude leads to enhancement in entropy generation because of larger temperature and velocity gradients. This phenomenon appears second and even third peaks in entropy generation plots in higher pulsation frequency and amplitude. Research limitations/implications – The predictions may be extended to include various pulsation signal shape, multiple jet configuration, the radiation effect and phase difference between jets. Practical implications – The results of this paper are a valuable source of information for active control of transport phenomena in impinging jet configurations which is used in different industrial applications such as cooling, heating and drying processes. Originality/value – In this paper the entropy generation of pulsed impinging jet was studied for the first time and a comprehensive discussion on numerical results is provided.

scholarly journals MHD and Slip Effect in Micropolar Hybrid Nanofluid and Heat Transfer over a Stretching Sheet with Thermal Radiation and Non-uniform Heat Source/Sink

CFD letters ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 121-130
Author(s):  
Nur Faizzati Ahmad Faizal ◽  
Norihan Md Ariffin ◽  
Yong Faezah Rahim ◽  
Mohd Ezad Hafidz Hafidzuddin ◽  
Nadihah Wahi
Keyword(s):  
Heat Transfer ◽  
Angular Velocity ◽  
Heat Source ◽  
Thermal Radiation ◽  
Stretching Sheet ◽  
Velocity Profiles ◽  
Hybrid Nanofluid ◽  
Temperature Profiles ◽  
Uniform Heat ◽  
Source Sink

In the presence of slips, non-uniform heat source/sink, thermal radiation and magnetohydrodynamic (MHD), micropolar hybrid nanofluid and heat transfer over a stretching sheet has been studied. The problem is modelled as a mathematical formulation that involves a system of the partial differential equation. The similarity approach is adopted, and self-similar ordinary differential equations are obtained and then those are solved numerically using the shooting method. The flow field is affected by the presence of physical parameters such as micropolar parameter, magnetic field parameter, suction parameter and slip parameter whereas the temperature field is affected by thermal radiation parameter, space-dependent parameter, temperature-dependent internal heat generation/absorption parameter, Prantl number and Biot number. The skin friction coefficient, couple stress and local Nusselt number are tabulated and analysed. The effects of the governing parameters on the velocity profiles, angular velocity profiles and temperature profiles are illustrated graphically. The results of velocity profiles, angular velocity profiles and temperature profiles are also obtained for several values of each parameters involved.

scholarly journals Influence of heat generation/absorption and stagnation point on polystyrene–TiO2/H2O hybrid nanofluid flow

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sadaf Masood ◽  
Muhammad Farooq ◽  
Aisha Anjum
Keyword(s):  
Heat Transfer ◽  
Differential Equations ◽  
Stagnation Point ◽  
Entropy Generation ◽  
Heat Generation ◽  
Velocity Ratio ◽  
Hybrid Nanofluid ◽  
Engineering System ◽  
Nanofluid Flow ◽  
Homotopy Analysis

AbstractThis article focuses on hybrid nanofluid flow induced by stretched surface. The present context covers stagnation point flow of a hybrid nanofluid with the effect of heat generation/absorption. Currently most famous class of nanofluids is Hybrid nanofluid. It contains polystyrene and titanium oxide as a nanoparticles and water as a base fluid. First time attributes of heat transfer are evaluated by utilizing polystyrene–TiO2/H2O hybrid nanofluid with heat generation/absorption. Partial differential equations are converted into ordinary differential equation by using appropriate transformations for heat and velocity. Homotopy analysis method is operated for solution of ordinary differential equations. Flow and heat are disclosed graphically for unlike parameters. Resistive force and heat transfer rate is deliberated mathematically and graphically. It is deduced that velocity field enhanced for velocity ratio parameter whereas temperature field grows for heat generation/absorption coefficient. To judge the production of any engineering system entropy generation is also calculated. It is noticed that entropy generation grows for Prandtl number and Eckert number while it shows opposite behavior for temperature difference parameter.

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