scholarly journals Heat transfer and entropy analysis of Maxwell hybrid nanofluid including effects of inclined magnetic field, Joule heating and thermal radiation

2020 ◽  
Vol 13 (10) ◽  
pp. 2667-2690 ◽  
Author(s):  
Asim Aziz ◽  
◽  
Wasim Jamshed ◽  
Yasir Ali ◽  
Moniba Shams ◽  
...  
Author(s):  
Harish Babu D ◽  
Venkateswarlu B ◽  
Sarojamma G ◽  
Satya Narayana P.V.

Abstract Significance of the study: Hybrid nanofluids attract the attention of many current researchers due to the enhanced heat transport rate in many engineering and industrial applications. The influence of an inclined magnetic field over an exponentially stretched sheet in the presence of thermal radiation cannot be ignored and the literature available in this domain is scanty. The novelty of this communication is to explore the impact of inclined magnetic field and thermal radiative heat on the hybrid nanofluid consisting of and nanoparticles in the base fluid, water. Aim of the study: A mathematical model for hybrid nanofluid is proposed to study the influence of oblique magnetic field and thermal radiation on an exponentially elongated sheet. A comparision of the thermal characteristics of the hybrid nanofluid and the mono nanofluids is made. Research methodology: The governing flow equations are transformed into a system of ODEs with the assistance of similarity variables and are then computationally addressed using bvp4c.The graphs are displayed for velocity, heat measure and reduced frictional coefficients for selected flow parameters. Results: Hybrid nanofluid has 1-4 % growth in the rate of heat transfer when compared to mono nanofluid while it is 1-4.5% in comparison to viscous fluid for increasing radiation parameter. Conclusion: The outcomes of this work revealed that the heat transfer as a consequence of the dispersion of dual nanomaterials is more promising than the mono nanofluid. To accomplish very effective cooling/ heating in industrial and engineering applications, hybrid nanofluids can substitute mono nanofluids.


2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Subhasree Dutta ◽  
Somnath Bhattacharyya ◽  
Ioan Pop

Purpose This study aims to numerically analyse the impact of an inclined magnetic field and Joule heating on the conjugate heat transfer because of the mixed convection of an Al2O3–water nanofluid in a thick wall enclosure. Design/methodology/approach A horizontal temperature gradient together with the shear-driven Flow creates the mixed convection inside the enclosure. The nonhomogeneous model, in which the nanoparticles have a slip velocity because of thermophoresis and Brownian diffusion, is adopted in the present study. The thermal performance is evaluated by determining the entropy generation, which includes the contribution because of magnetic field. A control volume method over a staggered grid arrangement is adopted to compute the governing equations. Findings The Lorentz force created by the applied magnetic field has an adverse effect on the flow and thermal field, and consequently, the heat transfer and entropy generation attenuate because of the presence of magnetic force. The Joule heating enhances the fluid temperature but attenuates the heat transfer. The impact of the magnetic field diminishes as the angle of inclination of the magnetic field is increased, and it manifests as the volume fraction of nanoparticles is increased. Addition of nanoparticles enhances both the heat transfer and entropy generation compared to the clear fluid with enhancement in entropy generation higher than the rate by which the heat transfer augments. The average Bejan number and mixing-cup temperature are evaluated to analyse the thermodynamic characteristics of the nanofluid. Originality/value This literature survey suggests that the impact of an inclined magnetic field and Joule heating on conjugate heat transfer based on a two-phase model has not been addressed before. The impact of the relative slip velocity of nanoparticles diminishes as the magnetic field becomes stronger.


Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 506
Author(s):  
Sufian Munawar ◽  
Najma Saleem ◽  
Waqar Ahmad Khan ◽  
Sumiya Nasir

The hybrid nanofluids have efficient thermal networking due to the trade-off between the pros and cons of the more than one type of suspension. In the current study, water-based hybrid nanofluid is used to investigate mixed convection in a squared enclosure heated with a circular center heater. The cavity is placed inclined under the uniform inclined magnetic field. The squared cavity comprises of two adiabatic vertical walls and two cold horizontal walls. The governing equations are normalized using a suitable set of variables and are solved with the finite element method. A comparison is provided with previously reported results at limiting case. The grid independence is examined for the Nusselt number at the central heater. The analysis reveals the effective role of the concentration of hybrid nanofluid particles in enhancing the heat spread. The results indicate that adding 2% concentration of Ag-MgO hybrid nanoparticles causes an 18.3% uprise in the Nusselt number at the central heater. The heat transfer rate enhances for increasing Hartmann number between 0 and 10 but decreases over 10. For better heat transfer augmentation, a heater with a smaller radius is recommended for the free convection. In contrast, a heater with a larger radius serves the purpose in case of forced convection.


2015 ◽  
Vol 63 (2) ◽  
pp. 501-514 ◽  
Author(s):  
F.M. Abbasi ◽  
T. Hayat ◽  
A. Alsaedi

Abstract This article describes the influence of an inclined magnetic field on the mixed convective peristaltic transport of fluid in an inclined channel. Two types of non-Newtonian fluids are considered. The problem formulation is presented for the Eyring-Prandtl and Sutterby fluids. Viscous dissipation and Joule heating in the heat transfer process are retained. The presence of a heat source in the energy equation is ensured. The resulting problems are solved by the perturbation method. The plots for different parameters of interest are given and discussed. Numerical values of a heat transfer rate are given and analyzed


2021 ◽  
Vol 13 (9) ◽  
pp. 5086
Author(s):  
Fatih Selimefendigil ◽  
Hakan F. Oztop ◽  
Ali J. Chamkha

Single and double impinging jets heat transfer of non-Newtonian power law nanofluid on a partly curved surface under the inclined magnetic field effects is analyzed with finite element method. The numerical work is performed for various values of Reynolds number (Re, between 100 and 300), Hartmann number (Ha, between 0 and 10), magnetic field inclination (γ, between 0 and 90), curved wall aspect ratio (AR, between 01. and 1.2), power law index (n, between 0.8 and 1.2), nanoparticle volume fraction (ϕ, between 0 and 0.04) and particle size in nm (dp, between 20 and 80). The amount of rise in average Nusselt (Nu) number with Re number depends upon the power law index while the discrepancy between the Newtonian fluid case becomes higher with higher values of power law indices. As compared to case with n = 1, discrepancy in the average Nu number are obtained as −38% and 71.5% for cases with n = 0.8 and n = 1.2. The magnetic field strength and inclination can be used to control the size and number or vortices. As magnetic field is imposed at the higher strength, the average Nu reduces by about 26.6% and 7.5% for single and double jets with n greater than 1 while it increases by about 4.78% and 12.58% with n less than 1. The inclination of magnetic field also plays an important role on the amount of enhancement in the average Nu number for different n values. The aspect ratio of the curved wall affects the flow field slightly while the average Nu variation becomes 5%. Average Nu number increases with higher solid particle volume fraction and with smaller particle size. At the highest particle size, it is increased by about 14%. There is 7% variation in the average Nu number when cases with lowest and highest particle size are compared. Finally, convective heat transfer performance modeling with four inputs and one output is successfully obtained by using Adaptive Neuro-Fuzzy Interface System (ANFIS) which provides fast and accurate prediction results.


2021 ◽  
Vol 11 (10) ◽  
pp. 4683
Author(s):  
Areum Lee ◽  
Chinnasamy Veerakumar ◽  
Honghyun Cho

This paper discusses the forced convective heat transfer characteristics of water–ethylene glycol (EG)-based Fe3O4 nanofluid and Fe3O4–MWCNT hybrid nanofluid under the effect of a magnetic field. The results indicated that the convective heat transfer coefficient of magnetic nanofluids increased with an increase in the strength of the magnetic field. When the magnetic field strength was varied from 0 to 750 G, the maximum convective heat transfer coefficients were observed for the 0.2 wt% Fe3O4 and 0.1 wt% Fe3O4–MWNCT nanofluids, and the improvements were approximately 2.78% and 3.23%, respectively. The average pressure drops for 0.2 wt% Fe3O4 and 0.2 wt% Fe3O4–MWNCT nanofluids increased by about 4.73% and 5.23%, respectively. Owing to the extensive aggregation of nanoparticles by the external magnetic field, the heat transfer coefficient of the 0.1 wt% Fe3O4–MWNCT hybrid nanofluid was 5% higher than that of the 0.2 wt% Fe3O4 nanofluid. Therefore, the convective heat transfer can be enhanced by the dispersion stability of the nanoparticles and optimization of the magnetic field strength.


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