scholarly journals Effect of electro-osmosis and mixed convection on nano-bio-fluid with non-spherical particles in a curved channel

2018 ◽  
Vol 19 (1) ◽  
pp. 108 ◽  
Author(s):  
N. Ijaz ◽  
Ahmed Zeeshan ◽  
S.U. Rehman
Keyword(s):  
Heat Transfer ◽  
Mixed Convection ◽  
Base Fluid ◽  
Spherical Particles ◽  
Spherical Nanoparticles ◽  
Curved Channel ◽  
Blade Shape ◽  
Electro Osmosis ◽  
Flexible Walls ◽  
Aqueous Base

This paper resigns to study effects of electro-kinetic force due to presence of electrical charge layer on the walls of the channel. The nano-bio-fluid fills the void between two concentric curved plates. The flow is induced due to peristaltic wave on flexible walls. The effects of mixed convection along with heat transfer are accounted. Furthermore, the focus is on effects of shapes of non-spherical nanoparticles in nano-bio-fluid and its effects on the flow. Nanofluids are important in treatment of cancer and other diseases in tissues which are normally not reachable by normal drug procedures. The problem is modeled for four types of non-spherical nanoparticles of alumina in aqueous base fluid. Numerical solution is obtained using Mathematica. Some important results are displaced through graphs. Empirical observations display that a significantly greater velocity for nanofluid with blade shape particles is offered followed by brick shaped particles. Numerical experiment also deems a rise in heat transfer due to presence of blade shapes particles.

Computer Simulation of Mixed Convection of Alumina-Deionized Water Nanofluid Over Four In-Line Electronic Chips Embedded in One Wall of a Vertical Rectangular Channel

2019 ◽  
Vol 12 (4) ◽  
Author(s):  
Nalla Ramu ◽  
P. S. Ghoshdastidar
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Heat Transfer Coefficient ◽  
Mixed Convection ◽  
Transfer Coefficient ◽  
Base Fluid ◽  
Rectangular Channel ◽  
Working Fluid ◽  
Al2o3 Nanoparticles ◽  
Enhancement Factors

Abstract This paper presents a computational study of mixed convection cooling of four in-line electronic chips by alumina-deionized (DI) water nanofluid. The chips are flush-mounted in the substrate of one wall of a vertical rectangular channel. The working fluid enters from the bottom with uniform velocity and temperature and exits from the top after becoming fully developed. The nanofluid properties are obtained from the past experimental studies. The nanofluid performance is estimated by computing the enhancement factor which is the ratio of chips averaged heat transfer coefficient in nanofluid to that in base fluid. An exhaustive parametric study is performed to evaluate the dependence of nanoparticle volume fraction, diameter of Al2O3 nanoparticles in the range of 13–87.5 nm, Reynolds number, inlet velocity, chip heat flux, and mass flowrate on enhancement in heat transfer coefficient. It is found that nanofluids with smaller particle diameters have higher enhancement factors. It is also observed that enhancement factors are higher when the nanofluid Reynolds number is kept equal to that of the base fluid as compared with the cases of equal inlet velocities and equal mass flowrates. The linear variation in mean pressure along the channel is observed and is higher for smaller nanoparticle diameters.

scholarly journals Investigation of Adding Cu Particles to Base Fluid on Mixed Convection Heat Transfer in a Ventilated Square Cavity

2015 ◽  
Vol 127 ◽  
pp. 33-39 ◽  
Author(s):  
Aran Alaie Sheikhrobat ◽  
Kamel Milani Shirvan ◽  
Soroush Mirzakhanlari ◽  
Teimour Behzadi
Keyword(s):  
Heat Transfer ◽  
Mixed Convection ◽  
Base Fluid ◽  
Convection Heat Transfer ◽  
Convection Heat ◽  
Square Cavity ◽  
Mixed Convection Heat Transfer

Laminar Convective Heat Transfer of Alumina-Polyalphaolefin Nanofluids Containing Spherical and Non-Spherical Nanoparticles

2011 ◽  
Author(s):  
Leyuan Yu ◽  
Dong Liu ◽  
Frank Botz
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Thermophysical Properties ◽  
Stokes Equations ◽  
Effective Medium Theory ◽  
Spherical Particles ◽  
Spherical Nanoparticles ◽  
Fluid Medium ◽  
The Past

As a promising candidate for advanced heat transfer fluids, nanofluids have been studied extensively during the past decade. In contrast to the early reports of dramatic heat transfer enhancement even at extremely low particle concentrations, the most recent studies suggest the laminar convective heat transfer of nanofluids is only mildly augmented and can be predicted by the conventional Navier-Stokes equations. The majority of the past studies were limited to water-based nanofluids synthesized from spherical nanoparticles. No systematic information is yet available for the convective heat transfer of nanofluids containing non-spherical particles, especially those formulated with the base fluid other than water. An experimental study was conducted in this work to investigate the thermophysical properties and convective heat transfer characteristics of Al2O3-Polyalphaolefin (PAO) nanofluids containing both spherical and rod-like nanoparticles. The effective viscosity and thermal conductivity were measured and compared to predictions from the effective medium theory. The friction factor and local Nusselt number were also measured for the laminar flow regime. It was found that established theoretical correlations can satisfactorily predict the experimental data for nanofluids containing spherical nanoparticles; however, they are less successful for nanofluids with nanorods. The possible reasons may be attributed to the shear-induced alignment of non-spherical nanoparticles and its subsequent influence on the development of the thermal boundary layer. The results suggest that the hydrodynamic interactions between the non-spherical nanoparticles and the surrounding fluid medium have a significant impact on the thermophysical properties as well as on the thermal transport characteristics of nanofluids.

Investigation of mixed convection and particle dispersion of nanofluids in a vertical duct

2016 ◽  
Vol 230 (20) ◽  
pp. 3691-3705 ◽  
Author(s):  
Farzad Bazdidi-Tehrani ◽  
Mohammad Sedaghatnejad ◽  
Seyed Iman Vasefi ◽  
Naeem Ekrami Jolandan
Keyword(s):  
Heat Transfer ◽  
Aspect Ratio ◽  
Mixed Convection ◽  
Base Fluid ◽  
Particle Dispersion ◽  
Two Phase ◽  
Wide Range ◽  
Centre Region ◽  
Nanoparticles Concentration ◽  
Number Formula

In the present paper, mixed convection of TiO2-water and CuO-water nanofluids in a laminar flow within a vertical rectangular duct is investigated numerically. The two-phase Euler-Lagrange approach is applied to simulate nanoparticles dispersion in the base fluid. Effects of nanoparticles concentration, aspect ratio, buoyancy and Brownian and Thermophoretic forces in a wide range of Richardson number ([Formula: see text]) on the hydrodynamics and thermal parameters are presented and discussed. It is observed that at [Formula: see text], dispersion of nanoparticles in the base fluid improves heat transfer rate more considerably. Whilst an improvement in convective heat transfer of CuO-water nanofluids is shown to be more than 22% at [Formula: see text], it does not exceed 15% at [Formula: see text]. Moreover, at [Formula: see text], particles disperse in the centre region of duct cross section and variation in aspect ratio does not alter the amount of enhancement of heat transfer significantly.

scholarly journals G-jitter fully developed heat transfer by mixed convection flow of nanofluid in a vertical channel

2017 ◽  
Vol 13 (3) ◽  
Author(s):  
Wan Nor Zaleha Amin ◽  
Noraihan Afiqah Rawi ◽  
Mohd Ariff Admon ◽  
Sharidan Shafie
Keyword(s):  
Heat Transfer ◽  
Mixed Convection ◽  
Base Fluid ◽  
Volume Fraction ◽  
Vertical Channel ◽  
Convection Flow ◽  
Physical Parameters ◽  
Mixed Convection Flow ◽  
Temperature Ratio ◽  
Water Base

In this study, the effect of g-jitter fully developed heat transfer by mixed convection flow of nanofluid in a vertical channel is investigated. The nanoparticles of aluminum oxide and copper with water as a base fluid are used in this study. The equations corresponding to this study are solved analytically to find the exact solutions. The results of velocity and temperature profiles with the influence of physical parameters such as mixed convection, oscillation, temperature ratio and volume fraction of the nanoparticles are plotted and analyze in details. The behavior of steady state flow is also investigated. Results shown that as mixed convection, oscillation, and temperature ratio increased, the velocity profiles increased. The conductivity and viscosity of the nanofluid are also increased due to the increase of the volume fraction of nanoparticles in the water base fluid.

A Similarity Solution for Mixed-Convection Boundary Layer Nanofluid Flow on an Inclined Permeable Surface

2017 ◽  
Vol 9 (2) ◽  
Author(s):  
Masoud Ziaei-Rad ◽  
Abbas Kasaeipoor ◽  
Mohammad Mehdi Rashidi ◽  
Giulio Lorenzini
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Nusselt Number ◽  
Mixed Convection ◽  
Friction Factor ◽  
Base Fluid ◽  
Volume Fraction ◽  
Nanofluid Flow ◽  
Wall Suction ◽  
Surface Angle

This paper concerns with calculation of heat transfer and pressure drop in a mixed-convection nanofluid flow on a permeable inclined flat plate. Solution of governing boundary layer equations is presented for some values of injection/suction parameter (f0), surface angle (γ), Galileo number (Ga), mixed-convection parameter (λ), volume fraction (φ), and type of nanoparticles. The numerical outcomes are presented in terms of average skin friction coefficient (Cf) and Nusselt number (Nu). The results indicate that adding nanoparticles to the base fluid enhances both average friction factor and Nusselt number for a wide range of other effective parameters. We found that for a nanofluid with φ = 0.6, injection from the wall (f0 = −0.2) offers an enhancement of 30% in Cf than the base fluid, while this growth is about 35% for the same case with wall suction (f0 = 0.2). However, increasing the wall suction will linearly raise the heat transfer rate from the surface, similar for all range of nanoparticles volume fraction. The computations also showed that by changing the surface angle from horizontal state to 60 deg, the friction factor becomes 2.4 times by average for all φ's, while 25% increase yields in Nusselt number for the same case. For assisting flow, there is a favorable pressure gradient due to the buoyancy forces, which results in larger Cf and Nu than in opposing flows. We can also see that for all φ values, enhancing Ga/Re2 parameter from 0 to 0.005 makes the friction factor 4.5 times, while causes 50% increase in heat transfer coefficient. Finally, we realized that among the studied nanoparticles, the maximum influence on the friction and heat transfer belongs to copper nanoparticles.

Improvement of drug delivery micro-circulatory system with a novel pattern of CuO-Cu/blood hybrid nanofluid flow towards a porous stretching sheet

2019 ◽  
Vol 29 (11) ◽  
pp. 4408-4429 ◽  
Author(s):  
Saeed Dinarvand ◽  
Mohammadreza Nademi Rostami ◽  
Rassoul Dinarvand ◽  
Ioan Pop
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Drug Delivery ◽  
Prandtl Number ◽  
Mixed Convection ◽  
Base Fluid ◽  
Stretching Sheet ◽  
Circulatory System ◽  
Hybrid Nanofluid ◽  
Content Type

Purpose This paper aims to simulate the steady laminar mixed convection incompressible viscous and electrically conducting hybrid nanofluid (CuO-Cu/blood) flow near the plane stagnation-point over a horizontal porous stretching sheet along with an external magnetic field and induced magnetic field effects that can be applicable in the biomedical fields like the flow dynamics of the micro-circulatory system and especially in drug delivery. Design/methodology/approach The basic partial differential equations (PDEs) are altered to a set of dimensionless ordinary differential equations (ODEs) with the help of suitable similarity variables which are then solved numerically using bvp4c scheme from MATLAB. Inasmuch as validation results have shown a good agreement with previous reports, the present novel mass-based algorithm can be used in this problem with great confidence. Governing parameters are both nanoparticle masses, base fluid mass, empirical shape factor of both nanoparticles, suction/injection parameter, magnetic parameter, reciprocal magnetic Prandtl number, Prandtl number, heat source parameter, mixed convection parameter, permeability parameter and frequency ratio. The effect of these parameters on the flow and heat transfer characteristics of the problem is discussed in detail. Findings It is shown that the use of CuO and Cu hybrid nanoparticles can reduce the hemodynamics effect of the capillary relative to pure blood case. Moreover, as the imposed magnetic field enhances, the velocity of the blood decreases. Besides, when the blade shapes for both nanoparticles are taken into account, the local heat transfer rate is maximum that is also compatible with experimental observations. Originality/value An innovative mass-based model of CuO-Cu/blood hybrid nanofluid has been applied. The novel attitude to one-phase hybrid nanofluid model corresponds to considering nanoparticles mass as well as base fluid mass to computing the solid equivalent volume fraction, the solid equivalent density and also solid equivalent specific heat.

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