Entropy generation analysis of hybrid nanofluid in a microchannel with slip flow, convective boundary and nonlinear heat flux

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
S. Sindhu ◽  
B.J. Gireesha
Keyword(s):  
Base Fluid ◽  
Design Methodology ◽  
Flow Model ◽  
Slip Flow ◽  
Hybrid Nanofluid ◽  
Nanofluid Flow ◽  
Convective Boundary ◽  
Content Type ◽  
Thermal Features ◽  
Hybrid Mixtures

Purpose Thermal features of hybrid nanoliquid consist of Cu–Ti, CuO–TiO2 and C71500–Ti6Al4V/H2O as hybrid mixtures of nano-sized particles in a base fluid through a microchannel are inspected. In this study, flow model of Darcy–Forchheimer is hired to examine the flow of hybrid composition. Design/methodology/approach The equations which delineate the physical occurrence of the flow are resolved via Runge–Kutta–Fehlberg scheme united through shooting procedure. Findings It is established that flow velocity of hybrid nano composition satisfies the identity U_(CuO-TiO2/water)>U_(Cu–Ti/water)>U_(C71500–Ti6Al4V/water). Originality/value Hybrid nanofluid flow of Cu–Ti, CuO–TiO2 and C71500–Ti6Al4V/H2O hybrid mixtures in a base fluid through a microchannel are inspected.

MHD hybrid nanofluid flow with convective heat transfer over a permeable stretching/shrinking surface with radiation

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Nur Syahirah Wahid ◽  
Norihan Md Arifin ◽  
Najiyah Safwa Khashi'ie ◽  
Ioan Pop ◽  
Norfifah Bachok ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Volume Fraction ◽  
Hybrid Nanofluid ◽  
Convective Boundary Conditions ◽  
Nanofluid Flow ◽  
Convective Boundary ◽  
Content Type ◽  
Shrinking Surface

Purpose The purpose of this paper is to numerically investigate the hybrid nanofluid flow with the imposition of magnetohydrodynamic (MHD) and radiation effects alongside the convective boundary conditions over a permeable stretching/shrinking surface. Design/methodology/approach The mathematical model is formulated in the form of partial differential equations (PDEs) and are then transformed into the form of ordinary differential equations (ODEs) by using the similarity variables. The deriving ODEs are solved numerically by using the bvp4c solver in MATLAB software. Stability analysis also has been performed to determine the stable solution among the dual solutions obtain. For method validation purposes, a comparison of numerical results has been made with the previous studies. Findings The flow and the heat transfer of the fluid at the boundary layer are described through the plot of the velocity profile, temperature profile, skin friction coefficient and local Nusselt number that are presented graphically. Dual solutions are obtained, but only the first solution is stable. For the realizable solution at the shrinking surface, the proliferation of nanoparticle volume fraction (copper) and magnetic (magnetohydrodynamics) parameters can impede the boundary layer separation. Also, Biot number could enhance the temperature profile and the heat transfer rate at the shrinking surface region. The incrementation of 0.1% of Biot number has enhanced the heat transfer rate by approximately 0.1% and the incrementation of 0.5% volume fraction for copper has reduced the heat transfer rate by approximately 0.17%. Originality/value The presented model and numerical results are original and new. It can be used as a future reference for further investigation and related practical application. The main contribution of this investigation includes giving the initial prediction and providing the numerical data for the other researchers for their future reference regarding the impacts of nanoparticles volumetric concentration towards the main physical quantities of interest in the presence of magnetic and radiation parameters with the convective boundary conditions.

TiO2-Ag/blood hybrid nanofluid flow through an artery with applications of drug delivery and blood circulation in the respiratory system

2020 ◽  
Vol 30 (11) ◽  
pp. 4775-4796 ◽  
Author(s):  
Hamidreza Shojaie Chahregh ◽  
Saeed Dinarvand
Keyword(s):  
Drug Delivery ◽  
Base Fluid ◽  
Biological Fluid ◽  
Normal Pressure ◽  
Hybrid Nanoparticles ◽  
Porous Channel ◽  
Hybrid Nanofluid ◽  
Nanofluid Flow ◽  
Content Type ◽  
Flow Through

Purpose As transferring biological fluid through an artery is nowadays a pivotal subject, the purpose of this paper is to study the mathematical model of hybrid nanofluid flow comprising pure blood as base fluid and TiO2 and Ag as nanoparticles through the porous channel, which can be an applicable model for drug delivery. Design/methodology/approach Both walls of the channel have different permeability, which enables the fluid to enter and exit, and variable height, which dilates and squeezes at the uniform rate. By taking advantage of the similarity transformation technique, governing equations have been converted into a system of the non-linear ordinary differential equation. This problem is solved numerically by utilizing BVP4C built-in function in MATLAB software to explore the impacts of pertinent parameters. Findings The plots of velocity and temperature profile, normal pressure distribution and wall shear stress, as well as Nusselt number for involved parameters, are presented and the logic and physical reasons beyond them are highlighted. It has been observed that the asymmetry of the channel, caused by different permeability at walls, affects the nature of flow significantly. Originality/value To the best of the authors’ knowledge, no one has ever attempted to study the flow through a deformable porous channel with blood as a base fluid and as hybrid nanoparticles to describe medical phenomena and treatment applications. Indeed, the achievements of this paper are purely original and the numerical results were never published by any researcher.

Hybrid nanofluid flow and heat transfer past a vertical thin needle with prescribed surface heat flux

2019 ◽  
Vol 29 (12) ◽  
pp. 4875-4894 ◽  
Author(s):  
Iskandar Waini ◽  
Anuar Ishak ◽  
Ioan Pop
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Surface Heat Flux ◽  
Surface Heat ◽  
Dual Solutions ◽  
Hybrid Nanofluid ◽  
Nanofluid Flow ◽  
Needle Size ◽  
Content Type ◽  
Flow And Heat Transfer

Purpose The purpose of this paper is to study the steady mixed convection hybrid nanofluid flow and heat transfer past a vertical thin needle with prescribed surface heat flux. Design/methodology/approach The governing partial differential equations are transformed into a set of ordinary differential equations by using a similarity transformation. The transformed equations are then solved numerically using the boundary value problem solver (bvp4c) in Matlab software. The features of the skin friction coefficient and the local Nusselt number as well as the velocity and temperature profiles for different values of the governing parameters are analyzed and discussed. Findings It is found that dual solutions exist for a certain range of the mixed convection parameter where its critical values decrease with the increasing of the copper (Cu) nanoparticle volume fractions and for the smaller needle size. It is also observed that the increasing of the copper (Cu) nanoparticle volume fractions and the decreasing of the needle size tend to enhance the skin friction coefficient and the local Nusselt number on the needle surface. A temporal stability analysis is performed to determine the stability of the dual solutions in the long run, and it is revealed that only one of them is stable, while the other is unstable. Originality/value The problem of hybrid nanofluid flow and heat transfer past a vertical thin needle with prescribed surface heat flux is the important originality of the present study where the dual solutions for the opposing flow are obtained.

A theoretical investigation for mixed convection impact in non-Newtonian nanofluid stratified flow subjected to magnetic field

2019 ◽  
Vol 29 (8) ◽  
pp. 2948-2963 ◽  
Author(s):  
Muhammad Waqas ◽  
Muhammad Mudassar Gulzar ◽  
Zeeshan Asghar ◽  
Z. Ali ◽  
Waqar Azeem Khan ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Mixed Convection ◽  
Thermal Stratification ◽  
Design Methodology ◽  
Thermal Field ◽  
Second Grade ◽  
Second Grade Fluid ◽  
Nanofluid Flow ◽  
Content Type ◽  
Grade Fluid

Purpose The purpose of this study is to elaborate mixed convection impact in stratified nanofluid flow by convectively heated moving surface. Rheological relations of second-grade fluid are used for formulation. Magnetic field, heat absorption/generation and convective conditions are considered for modeling. Design/methodology/approach Convergent solutions are achieved using homotopy procedure. Findings The authors found opposing behavior for radiation and thermal stratification variables against thermal field. Originality/value No such analysis has yet been reported.

A study for steady nanofluid flow between parallel plates

2017 ◽  
Vol 34 (8) ◽  
pp. 2514-2527 ◽  
Author(s):  
Syed Tauseef Mohyud-din ◽  
Muhammad Asad Iqbal ◽  
Muhammad Shakeel
Keyword(s):  
Magnetic Field ◽  
Differential Equations ◽  
Uniform Magnetic Field ◽  
Design Methodology ◽  
Magnetic Parameter ◽  
Parallel Plates ◽  
Nanofluid Flow ◽  
Content Type ◽  
Viscosity Parameter ◽  
Variation Of Parameters

Purpose In this paper, the authors study the behavior of heat and mass transfer between parallel plates of a steady nanofluid flow in the presence of a uniform magnetic field. In the model of nanofluids, the essential effect of thermophoresis and Brownian motion has been encompassed. Design/methodology/approach The variation of parameters method has been exploited to solve the differential equations of nanofluid model. The legitimacy of the variation of parameters method has been corroborated by a comparison of foregoing works by many authors on viscous fluid. Findings An analysis of the model is performed for different parameters, namely, viscosity parameter, Brownian parameter, thermophoretic parameter and magnetic parameter. Originality/value The variation of parameters method proves to be very effective in solving nonlinear system of ordinary differential equations which frequently arise in fluid mechanics.

Betting on capital gains: housing speculation in Auckland, New Zealand

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Michael Rehm ◽  
Yang Yang
Keyword(s):  
New Zealand ◽  
Design Methodology ◽  
Flow Model ◽  
Capital Gains ◽  
Due Diligence ◽  
Political Leaders ◽  
Content Type ◽  
Policy Tool ◽  
Rental Property ◽  
Key Policy

Purpose The purpose of this paper is to examine housing speculation in Auckland, New Zealand, the second most unaffordable market in the world. Design/methodology/approach The study considers rental property purchases from 2002 to 2016 within the Auckland region. The authors apply a simple cash flow model that emulates the before-tax investment calculations used during purchasers’ due diligence. From this model, the authors determine whether purchases involved speculation on capital gains or not and the authors estimate the degree of speculation at the transaction level. Findings The authors find that housing speculation in Auckland is endemic and its housing market is a politically condoned, finance-fuelled casino with investors broadly betting on tax-free capital gains. Social implications Although political leaders have decried that the “speculation-driven housing bubble in Auckland is a social and economic disaster”, the government’s main anti-speculation tool – the Income Tax Act’s intention test – sits idle and inoperable. By holstering this key policy tool, politicians foster housing speculation and use residential property investment to buttress New Zealand’s asset-based welfare system. Originality/value The authors develop novel methods to objectively distinguish speculators from genuine investors, measure the speculative pressure applied by individual rental property purchasers and outline an evidence-based approach to operationalise New Zealand’s currently impotent anti-speculation tool, the intention test.

Bioconvective peristaltic flow of a third-grade nanofluid embodying gyrotactic microorganisms in the presence of Cu-blood nanoparticles with permeable walls

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Asha Shivappa Kotnurkar ◽  
Deepa C. Katagi
Keyword(s):  
Design Methodology ◽  
Adomian Decomposition Method ◽  
Peristaltic Flow ◽  
Third Grade ◽  
Nanofluid Flow ◽  
Gyrotactic Microorganisms ◽  
Content Type ◽  
Adomian Decomposition ◽  
Permeable Walls ◽  
Practical Implications

PurposeThe current paper investigates the bioconvective third-grade nanofluid flow containing gyrotactic organisms with Copper-blood nanoparticles in permeable walls.Design/methodology/approachThe equations governing the flow are solved by adopting the Adomian decomposition method.FindingsThe results show that the biconvection Peclet number decreases the density of motile microorganisms, and the Rayleigh number also decreases the velocity profile.Practical implicationsThe present study can be applied to design the higher generation microsystems.Originality/valueTo the best of the authors’ knowledge, no such investigation has been carried out in the literature.

scholarly journals Hydrodynamic and heat transfer analysis of dissimilar shaped nanoparticles-based hybrid nanofluids in a rotating frame with convective boundary condition

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Muhammad Ramzan ◽  
Nazia Shahmir ◽  
Hassan Ali S. Ghazwani ◽  
Kottakkaran Sooppy Nisar ◽  
Faizah M. Alharbi ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Boundary Condition ◽  
Base Fluid ◽  
Spherical Shape ◽  
Convective Boundary Condition ◽  
Heat Transfer Analysis ◽  
Hybrid Nanofluid ◽  
Convective Boundary ◽  
Hybrid Nanofluids ◽  
Low Efficiency

AbstractSolar thermal systems have low efficiency due to the working fluid's weak thermophysical characteristics. Thermo-physical characteristics of base fluid depend on particle concentration, diameter, and shapes. To assess a nanofluid's thermal performance in a solar collector, it is important to first understand the thermophysical changes that occur when nanoparticles are introduced to the base fluid. The aim of this study is, therefore, to analyze the hydrodynamic and heat characteristics of two different water-based hybrid nanofluids (used as a solar energy absorber) with varied particle shapes in a porous medium. As the heat transfer surface is exposed to the surrounding environment, the convective boundary condition is employed. Additionally, the flow of nanoliquid between two plates (in parallel) is observed influenced by velocity slip, non-uniform heat source-sink, linear thermal radiation. To make two targeted hybrid nanofluids, graphene is added as a cylindrical particle to water to make a nanofluid, and then silver is added as a platelet particle to the graphene/water nanofluid. For the second hybrid nanofluid, CuO spherical shape particles are introduced to the graphene/water nanofluid. The entropy of the system is also assessed. The Tiwari-Das nanofluid model is used. The translated mathematical formulations are then solved numerically. The physical and graphical behavior of significant parameters is studied.

Slip flow of hybrid nanofluid in presence of solar radiation

2021 ◽  
pp. 2250017
Author(s):  
Kalidas Das ◽  
Nilangshu Acharya ◽  
Md Tausif SK ◽  
Pinaki Ranjan Duari ◽  
Tanmoy Chakraborty
Keyword(s):  
Nusselt Number ◽  
Differential Equations ◽  
Slip Flow ◽  
Velocity Slip ◽  
Uniform Heat Flux ◽  
Hybrid Nanofluid ◽  
Nanofluid Flow ◽  
Fifth Order ◽  
The Impact ◽  
Final System

A theoretical model on MHD hybrid nanofluid flow in accordance with non-uniform heat flux and solar energy radiation has been studied in our work. Also, the impact of multiple slip conditions is presumed at the boundary. Comparative flow analyses for hybrid nanofluid (Al2O3/Cu–H2O) and single nanoparticle-based nanofluid (Cu–H2O) are addressed here with graphs and charts. The leading partial differential equations with boundary conditions have been converted into ordinary differential equations with the aid of similarity transformation. The final system is tackled via the fifth-order Runge–Kutta–Felberg method with shooting procedure and the computation is done using Maple 17. One of the interesting results shows that with the growth of thermal radiation, the Nusselt number for Cu–H2O is reduced by 26.16%, whereas for the same, Nusselt number for Al2O3/Cu–H2O is lessened by 27.38%. Fallout shows that with the growing values of velocity slip parameter, the thermal boundary layer thickness enlarges faster for Al2O3/Cu–H2O in comparison to Cu–H2O.

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