Free convection with MWCNT/water nanofluid having varying aspect ratio of MWCNT nanoparticle in thermally undulated enclosures
TL;DR: In this paper, a numerical simulation of 2D, steady and laminar free convection in rectangular cavities with different aspect ratios filled with water-based nanofluid is presented.
About: This article is published in International Journal of Mechanical Sciences.The article was published on 2020-07-15. It has received 12 citations till now. The article focuses on the topics: Nusselt number & Nanofluid.
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TL;DR: In this paper, the impact of Lorentz force on the transportation of operate fluid (water with a mixture of Fe3O4 and CuO) was analyzed using numerical method (CVFEM).
Abstract: In the current investigation, numerical method (CVFEM) was selected to show the impact of Lorentz force on transportation of operate fluid (water with a mixture of Fe3O4 and CuO). Adding the source terms associated with MHD (magneto-hydrodynamic) and porous zone leads to a mathematical model and utilizing vorticity formulation can make the equations to simplify. Not only the viscous and heating irreversibility but also permeable and magnetic terms were calculated. Nu and Be have been measured and based on results, two correlations were defined. As permeability and buoyancy effects augment, the velocity of operating fluid augments while lower velocity will be reported if Lorentz forces increases. Sgen,th decreases about 44% with augment of Ha but it augments about 100% with grow of Ra. Velocity augments about 75% with rise of Da while it declines about 50% with the growth of Ha. Intensification of Ha causes Nu to reduce about 7.85% while Be augments about 13.62%. As Da enhances, Be declines about 5.79 while Nu enhances about 49.11%. With the growth of Ra, Be decreases about 49.79% while Nu augments about 392%.
47 citations
TL;DR: In this paper, the effects of using an eccentric conic object near the thermoelectric device on the performance enhancement of the system were explored with numerical simulation using finite element method.
20 citations
TL;DR: In this article, the effect of a uniform partial magnetic field on fluid flow and heat transfer of multi-walled carbon nanofluid is done in a vented square cavity considering aiding and opposing flows without changing temperature boundary conditions.
Abstract: A numerical investigation for examining the effect of a uniform partial magnetic field on fluid flow and heat transfer of Multi Walled Carbon Nano Tube (MWCNT)-water nanofluid is done in a vented square cavity considering aiding and opposing flows without changing temperature boundary conditions. Modified Maron–Pierce equation for dynamic viscosity and Xue equation for thermal conductivity of nanofluid are achieved. The radial basis function (Rbf) based pseudo spectral method with cubic polyharmonic spline Rbf and nonuniform Gauss–Chebyshev–Lobatto (GCL) nodes are performed to solve the problem governed by stream function–vorticity formulation. The considered parameters are Richardson number ( 0 . 1 ≤ R i ≤ 100 ), the center of the partial magnetic field ( 0 . 25 ≤ l b c ≤ 0 . 75 ), Hartmann number ( 0 ≤ H a ≤ 100 ), Reynolds number ( 100 ≤ R e ≤ 400 ) and concentration of nanoparticles ( 0 ≤ ϕ ≤ 0 . 05 ). The results show that the partial magnetic field centered in the middle of the left wall has more reducing effect on convective heat transfer than the bottom and top centered one in both cases of flows. Convective heat transfer increases with the rise in solid volume fraction up to 0.02, but then a decrease is remarkably noticed.
9 citations
TL;DR: In this paper, the effect of variable fractal dimension and non-uniform diameter of Al 2 O 3 nanoparticles on heat and mass transfer due to natural convection in tilted square enclosures was examined.
Abstract: The present numerical work examines the effect of variable fractal dimension and non-uniform diameter of Al 2 O 3 nanoparticle on heat and mass transfer due to natural convection in tilted square enclosures. Enclosures are filled with Al 2 O 3 / H 2 O nanofluid and under constant heat and mass fluxes boundary conditions. The Navier-Stokes, energy, and concentration equations are solved numerically by finite difference method. Xu’s model [1] and Jang’s model [2] have been used to compute effective thermal conductivity and dynamic viscosity, respectively. Present work validated with published work experimentally and numerically. Influence of Al 2 O 3 nanoparticle’s non-uniform diameter, fractal dimension, and the ratio of minimum to maximum diameter are illustrated in the form of streamlines, heatlines, and masslines in addition to average Nusselt and Sherwood numbers at different enclosure tilt angles. Heat transfer increases with the decrement in mean nanoparticle diameter, and maximum at tilt angle of θ = 45 ∘ is observed for all Rayleigh numbers. At weak buoyancy effect ( Ra = 5 × 10 3 ) and minimum mean nanoparticle diameter ( d p = 1 nm ) , maximum of 30 % enhancement in overall heat transfer is observed at tilt angle, θ = 45 ∘ and nanoparticle volume fraction, ϕ = 5 % . At strong buoyancy effect ( Ra = 1 × 10 5 ) , maximum of 66 % enhancement in overall heat transfer is observed at same nanoparticle conditions and tilt angle. An increase in Rayleigh and Lewis number decreases the tilt angle at which maximum mass transfer occurred. Mass transfer is maximum in the range of mean nanoparticle diameter of d p = 25 − 50 nm.
4 citations
References
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Book•
01 Jan 1980
TL;DR: In this article, the authors focus on heat and mass transfer, fluid flow, chemical reaction, and other related processes that occur in engineering equipment, the natural environment, and living organisms.
Abstract: This book focuses on heat and mass transfer, fluid flow, chemical reaction, and other related processes that occur in engineering equipment, the natural environment, and living organisms. Using simple algebra and elementary calculus, the author develops numerical methods for predicting these processes mainly based on physical considerations. Through this approach, readers will develop a deeper understanding of the underlying physical aspects of heat transfer and fluid flow as well as improve their ability to analyze and interpret computed results.
21,858 citations
TL;DR: In this article, a model is developed to analyze heat transfer performance of nanofluids inside an enclosure taking into account the solid particle dispersion, where the transport equations are solved numerically using the finite-volume approach along with the alternating direct implicit procedure.
2,560 citations
TL;DR: In this paper, the authors used the finite volume technique to solve the governing equations of heat transfer and fluid flow due to buoyancy forces in a partially heated enclosure using nanofluids.
1,783 citations
TL;DR: In this paper, the authors studied the heat transfer behavior of aqueous suspensions of multi-walled carbon nanotubes (CNT nanofluids) flowing through a horizontal tube.
1,334 citations