Physical impact of thermo-diffusion and diffusion-thermo on Marangoni convective flow of hybrid nanofluid (MnZiFe2O4–NiZnFe2O4–H2O) with nonlinear heat source/sink and radiative heat flux

2021 ◽  
pp. 2141006
Author(s):  
Ying-Qing Song ◽  
M. Ijaz Khan ◽  
Sumaira Qayyum ◽  
R. J. Punith Gowda ◽  
R. Naveen Kumar ◽  
...  

The objective of this study is to illustrate the influence of Marangoni convection, nonlinear heat sink/source, thermal radiation, viscous dissipation, activation energy, Soret and Dufour effects on magnetohydrodynamics flow of nanofluid generated by rotating disk. Further, the entropy generation equation is derived as a function of velocity, concentration, and thermal gradients. The governing equations of the model along with associated boundary constraints are reduced to ordinary differential equations by adopting suitable similarity transformation. Later, these equations are tackled numerically by means of shooting technique. The whole examination is performed by using two distinctive nanoparticles of ferrites in particular, manganese zinc ferrite (MnZnFe2O4) and nickel zinc ferrite (NiZnFe2O4) in a carrier liquid [Formula: see text]. The physical characteristics of velocity, thermal, concentration entropy generation, skin friction, and Nusselt number against numerous pertinent parameters are discussed in detail and deliberated graphically. Result reveals that thermal gradient shows substantial enhancement for advanced values of heat sink/source parameter. The entropy production increases with an augmentation in the Brinkman number and Marangoni ratio values. The escalation in Marangoni ratio and Dufour number improves the rate of heat transference.

Author(s):  
R.J. Punith Gowda ◽  
R. Naveenkumar ◽  
J.K. Madhukesh ◽  
B.C. Prasannakumara ◽  
Rama Subba Reddy Gorla

The flow-through various disk movement has wide range of applications in manufacturing processes like, computer storage equipment’s, rotating machines, electronic and various types of medical equipment’s. Inspired from these applications, here we scrutinised the consequences of homogeneous-heterogeneous reactions and uniform heat source/sink on the three-dimensional (3D) hybrid SWCNT-MWCNT’s flow on time dependent moving upward/downward rotating disk. The renowned innovation of this paper is the application of the hybrid nanofluid made up of SWCNT and MWCNT’s. Heat generation/absorption effect for the disk that does not move up or down creates a dual flow on the disk. Alternatively, the rotation and upright motion of the disk creates a 3D flow on the surface which has not been considered in the open literature. The modelled PDE’s are reduced in to ODE’s by opting suitable similarity variables and boundary constraints. Here, we used RKF-45 method to obtain the numerical approximations by adopting shooting technique. The analysis of rate of heat transfer is done through graphs. Further, change in velocity, thermal and concentration profiles for various non-dimensional parameters are deliberated briefly and illustrated with the help of suitable plots. The results reveal that, the, rise in values of homogeneous and heterogeneous reaction parameters improve the rate of reaction which results in reduction of the distribution rate and diminishes the concentration gradient. An increase in expansion/contraction parameter enhances the velocity and thermal gradients.


2021 ◽  
pp. 2150342
Author(s):  
P.-Y. Xiong ◽  
M. Ijaz Khan ◽  
R. J. Punith Gowda ◽  
R. Naveen Kumar ◽  
B. C. Prasannakumara ◽  
...  

This investigation is about hybrid nanofluid flowing over a sheet. We considered two-dimensional Darcy–Forchheimer flow of different hybrid nanofluids with the influence of uniform heat source sink and nonlinear thermal radiation. Different nanoparticles can be used to improve the thermal conductivity of a liquid. A study comparing the various hybrid nanofluids to nanofluid is considered. Here, we have selected manganese Zinc ferrite and Nickel Zinc ferrite as nanoparticles with kerosene oil and engine oil as carrier liquids. Suitable similarity transformations are used to construct the required ordinary differential equations. The influence of several non-dimensional parameters on velocity and thermal gradients is analyzed through graphs. Also, entropy generation is computed and analyzed through graph for different involved parameters. Here, we observed that [Formula: see text]–[Formula: see text]–[Formula: see text]–[Formula: see text] had lower velocity when compared to other two solutions. The entropy generation and Bejan number are high in [Formula: see text]–[Formula: see text]–[Formula: see text] when compared to [Formula: see text]–[Formula: see text]–[Formula: see text]–[Formula: see text] and [Formula: see text]–[Formula: see text]–[Formula: see text] and increase in heat generation parameter increases the rate of heat transfer.


Micromachines ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 887
Author(s):  
Nabeela Parveen ◽  
Muhammad Awais ◽  
Saeed Ehsan Awan ◽  
Wasim Ullah Khan ◽  
Yigang He ◽  
...  

This research concerns the heat transfer and entropy generation analysis in the MHD axisymmetric flow of Al2O3-Cu/H2O hybrid nanofluid. The magnetic induction effect is considered for large magnetic Reynolds number. The influences of thermal radiations, viscous dissipation and convective temperature conditions over flow are studied. The problem is modeled using boundary layer theory, Maxwell’s equations and Fourier’s conduction law along with defined physical factors. Similarity transformations are utilized for model simplification which is analytically solved with the homotopy analysis method. The h-curves upto 20th order for solutions establishes the stability and convergence of the adopted computational method. Rheological impacts of involved parameters on flow variables and entropy generation number are demonstrated via graphs and tables. The study reveals that entropy in system of hybrid nanofluid affected by magnetic induction declines for [...]


Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 498
Author(s):  
Wasim Ullah Khan ◽  
Muhammad Awais ◽  
Nabeela Parveen ◽  
Aamir Ali ◽  
Saeed Ehsan Awan ◽  
...  

The current study is an attempt to analytically characterize the second law analysis and mixed convective rheology of the (Al2O3–Ag/H2O) hybrid nanofluid flow influenced by magnetic induction effects towards a stretching sheet. Viscous dissipation and internal heat generation effects are encountered in the analysis as well. The mathematical model of partial differential equations is fabricated by employing boundary-layer approximation. The transformed system of nonlinear ordinary differential equations is solved using the homotopy analysis method. The entropy generation number is formulated in terms of fluid friction, heat transfer and Joule heating. The effects of dimensionless parameters on flow variables and entropy generation number are examined using graphs and tables. Further, the convergence of HAM solutions is examined in terms of defined physical quantities up to 20th iterations, and confirmed. It is observed that large λ1 upgrades velocity, entropy generation and heat transfer rate, and drops the temperature. High values of δ enlarge velocity and temperature while reducing heat transport and entropy generation number. Viscous dissipation strongly influences an increase in flow and heat transfer rate caused by a no-slip condition on the sheet.


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