MHD flow of non-Newtonian ferro nanofluid between two vertical porous walls with Cattaneo–Christov heat flux, entropy generation, and time-dependent pressure gradient

This article studies the magnetohydrodynamic flow of non-Newtonian ferro nanofluid subject to time-dependent pressure gradient between two vertical permeable walls with Cattaneo–Christov heat flux and entropy generation. In this study, blood is considered as non-Newtonian fluid (couple stress fluid). Nanoparticles’ shape factor, Joule heating, viscous dissipation, and radiative heat impacts are examined. This investigation is crucial in nanodrug delivery, pharmaceutical processes, microelectronics, biomedicines, and dynamics of physiological fluids. The flow governing partial differential equations are transformed into the system of ordinary differential equations by deploying the perturbation process and then handled with Runge–Kutta 4th-order procedure aided by the shooting approach. Hamilton–Crosser model is employed to analyze the thermal conductivity of different shapes of nanoparticles. The obtained results reveal that intensifying Eckert number leads to a higher temperature, while the reverse is true for increased thermal relaxation parameter. Heat transfer rate escalates for increasing thermal radiation. Entropy dwindles for intensifying thermal relaxation parameter

Heat transfer in cavities: configurative systematic review

No abstract available

Radiative heat transfer in MHD mixed convection flow of nanofluids along a vertical channel

Over the past few decades, nanofluids have emerged as a promising technology for the enhancement of the intrinsic thermophysical properties of many convectional heat transfer fluids such as water and oil. Many researchers have been investigated the merits of dispersing nanometer-sized particles into base fluids to enhance heat transfer, thermal conductivity and viscosity of the fluids. Therefore, this research focused on radiative heat transfer in magnethohydrodynamics mixed convection flow in a channel filled with nanofluids containing different type of nanoparticles. Five types of nanoparticles (Al2O3, 3 4Fe O , Cu, 2 TiO , and Ag) with five different shapes (platelet, blade, cylinder, brick and spherical) were used in water 2 (H O) and ethylene glycol 2 6 2 (C H O), as conventional base fluid. An important subtype of nanofluids called ferrofluids 3 4 (Fe O in water based nanofluids) was also studied. Four different problems were modelled as partial differential equations with physical boundary conditions. In the first three problems, the channel walls were taken rigid, while the fourth problem the walls were chosen permeable where suction or injection was taking place. Perturbed type analytical solutions for velocity and temperature were obtained and discussed graphically in various graphs. Results for skin friction and Nusselt number were also computed and presented in tabular forms. This study showed that 2 6 2 C H O was the better convectional base fluid compared to 2 H O because of the higher viscosity and thermal conductivity. Ag nanoparticles had the highest thermal conductivity and viscosity compared to other type of nanoparticles. Increasing nanoparticles size had caused variation in velocity. It was also observed that, variation in velocity for Ag nanoparticles was obtained at low volume concentration, whereas for 2 3 Al O nanoparticles, this variation was observed only at high volume concentration. Velocity increases with increasing Grashof number, radiation, heat generation and permeability parameters, but decreases with increasing magnetic parameter and volume fraction of nanoparticles. However, the effects of these parameters were quite different in the case of suction and injection. Results had also shown that, temperature increases with increasing radiation and heat generation parameters. In this study, the temperature of ferrofluids was found smaller when compared to the temperature of nanofluids

Comparative heat transfer analysis of electroconductive Fe3O4 −MWCNT−water and Fe3O4 −MWCNT−kerosene hybrid nanofluids in a square porous cavity using the non-Fourier heat flux model

The analysis on heat transmission and fluid flow characteristics within the cavity is useful to improve the features of several applications including energy storage devices and hybrid fuel cells. With this motivation, the present model investigates the characteristics of magneto-convective heat transmission and fluid flow within a square porous enclosure with hot and cold slits. The heat transfer features of electrically conducting hybrid nanofluids Fe3O4−MWCNT−water and Fe3O4 − MWCNT−kerosene is analyzed inside the enclosure. The non-Fourier thermal flux model is deployed and the internal heat absorption/generation effect is considered. The Marker-And-Cell (MAC) numerical scheme is adopted to solve the transformed dimensionless mathematical model with associated initial-boundary conditions. An exhaustive parametric investigation is implemented to estimate the influence of key parameters on the transport phenomena. The computations show that augmenting the Hartmann number values modify the fluid flow and temperature features substantially for both the hybrid nanofluids. Enhancing the values of nanoparticles volume fraction promotes the heat transfer. When 5% Fe3O4 − MWCNT nanoparticles are suspended into water and kerosene base fluids, Fe3O4 − MWCNT−kerosene hybrid nanofluid achieves 6.85% higher mean heat transfer rate compared to Fe3O4 − MWCNT−water hybrid nanoliquid. In the existence of heat absorption, the mean rate of heat transfer of Fe3O4 − MWCNT−water hybrid nanofluid is 78.92% lower than Fe3O4 − MWCNT−kerosene hybrid nanoliquid. Greater energy transmission is noticed in the case of Fe3O4 − MWCNT−kerosene hybrid nanofluid and the enhanced fluid flow is noticed in the case of Fe3O4 − MWCNT−water hybrid nanofluid. Fourier’s model (δe = 0) estimates higher heat transfer rate than that of the Cattaneo–Christov (non-Fourier) heat flux model (δe ̸= 0)

Shape effect on MHD flow of time fractional Ferro-Brinkman type nanofluid with ramped heating

The colloidal suspension of nanometer-sized particles of Fe3O4 in traditional base fluids is referred to as Ferro-nanofluids. These fluids have many technological applications such as cell separation, drug delivery, magnetic resonance imaging, heat dissipation, damping, and dynamic sealing. Due to the massive applications of Ferro-nanofluids, the main objective of this study is to consider the MHD flow of water-based Ferro-nanofluid in the presence of thermal radiation, heat generation, and nanoparticle shape effect. The Caputo-Fabrizio time-fractional Brinkman type fluid model is utilized to demonstrate the proposed flow phenomenon with oscillating and ramped heating boundary conditions. The Laplace transform method is used to solve the model for both ramped and isothermal heating for exact solutions. The ramped and isothermal solutions are simultaneously plotted in the various figures to study the influence of pertinent flow parameters. The results revealed that the fractional parameter has a great impact on both temperature and velocity fields. In the case of ramped heating, both temperature and velocity fields decreasing with increasing fractional parameter. However, in the isothermal case, this trend reverses near the plate and gradually, ramped, and isothermal heating became alike away from the plate for the fractional parameter. Finally, the solutions for temperature and velocity fields are reduced to classical form and validated with already published results

Upshot of heterogeneous catalysis in a nanofluid flow over a rotating disk with slip effects and Entropy optimization analysis

The present study examines homogeneous (HOM)–heterogeneous (HET) reaction in magnetohydrodynamic flow through a porous media on the surface of a rotating disk. Preceding investigations mainly concentrated on the catalysis for the rotating disk; we modeled the impact of HET catalysis in a permeable media over a rotating disk with slip condition at the boundary. The HOM reaction is followed by isothermal cubic autocatalysis, however, the HET reactions occur on the surface governed by first-order kinetics. Additionally, entropy minimization analysis is also conducted for the envisioned mathematical model. The similarity transformations are employed to convert the envisaged model into a non-dimensional form. The system of the modeled problem with ordinary differential equations is analyzed numerically by using MATLAB built-in bvp4c function. The behavior of the emerging parameters versus the thermal, concentration, and velocity distributions are depicted graphically with requisite discussion abiding the thumb rules. It is learned that the rate of the surface catalyzed reaction is strengthened if the interfacial area of the permeable media is enhanced. Thus, a spongy medium can significantly curtail the reaction time. It is also noticed that the amplitude of velocity and thermal profile is maximum for the smallest value of the velocity slip parameter. Heat transfer rate declines for thermophoresis and the Brownian motion parameter with respect to the thermal slip parameter. The cogency of the developed model is also validated by making a comparison of the existing results with a published article under some constraints. Excellent harmony between the two results is noted

Proceedings of the 10th Australasian Heat and Mass Transfer Conference (AHMT2016)

Proceedings of The 10th Australasian Heat and Mass Transfer Conference (AHMT2016). The proceedings contain the selected full-length papers from the 10th Australasian Conference of Heat and Mass Transfer held in Brisbane, Australia on 14-15 July 2016. The conference was organised by Queensland University of Technology under the auspices of the Australasian Fluid and Thermal Engineering Society (AFTES) of Engineers Australia. Scientifically, these collected articles reflect recent progress made in heat and mass transfer in the Australasian community, including both fundamental and applied topics in the broad areas of convection, conduction, radiation, turbulence, multi-phase flow, combustion, drying, heat exchangers, phase change, computational methods, experimental methods, and other significant thermal processes in environmental, industrial, and process engineering. All the papers published in this volume were reviewed under a rigorous review process, where at least two reviews were received for each paper, according to the HERDC standard. The Organizing Committee is grateful to all of the contributors who made this volume possible. We would like to express our sincere appreciation to all authors and reviewers for their excellent contributions as well as the AHMT2016 scientific committee and financial support provided by Queensland University of Technology and Engineers Australi

Transverse magnetic field driven modification in unsteady peristaltic transport with electrical double layer effects

The influence of transverse magnetic field on time-dependent peristaltic transport of electrically-conducting fluids through a microchannel under an applied external electric field with induced electric field effect is considered, based on lubrication theory approximations. The electrohydrodynamic (EHD) problem is also simplified under the Debye linearization. Closed-form solutions for the linearized dimensionless boundary value problem are derived. With increasing Hartmann number, the formation of bolus in the regime (associated with trapping) is inhibited up to a critical value of magnetic field. Flow rate, axial velocity and local wall shear stress are strongly decreased with greater Hartmann number whereas pressure difference is enhanced with higher Hartmann number at low time values but reduced with greater elapse in time. With greater electro-osmotic parameter (i.e. smaller Debye length), maximum time-averaged flow rate is enhanced, whereas the axial velocity is reduced. An increase in electrical field parameter (i.e. maximum electro-osmotic velocity) causes an increase in maximum time-averaged flow rate. The simulations find applications in electromagnetic peristaltic micro-pumps in medical engineering and also “smart” fluid pumping systems in nuclear and aerospace industries

Computational Fluid Dynamics 2020

This book presents a collection of works published in a recent Special Issue (SI) entitled “Computational Fluid Dynamics”. These works address the development and validation of existent numerical solvers for fluid flow problems and their related applications. They present complex nonlinear, non-Newtonian fluid flow problems that are (in some cases) coupled with heat transfer, phase change, nanofluidic, and magnetohydrodynamics (MHD) phenomena. The applications are wide and range from aerodynamic drag and pressure waves to geometrical blade modification on aerodynamics characteristics of high-pressure gas turbines, hydromagnetic flow arising in porous regions, optimal design of isothermal sloshing vessels to evaluation of (hybrid) nanofluid properties, their control using MHD, and their effect on different modes of heat transfer. Recent advances in numerical, theoretical, and experimental methodologies, as well as new physics, new methodological developments, and their limitations are presented within the current book. Among others, in the presented works, special attention is paid to validating and improving the accuracy of the presented methodologies. This book brings together a collection of inter/multidisciplinary works on many engineering applications in a coherent manner