Mathematical model for ciliary-induced transport in MHD flow of Cu-H2O nanoßuids with magnetic induction

Motivated by novel developments in surface-modified, nanoscale, magnetohydrodynamic (MHD) biomedical devices, we study theoretically the ciliary induced transport by metachronal wave propagation in hydromagnetic flow of copper-water nanofluids through a parallel plate channel. Under the physiological constraints, creeping flow is taken into consideration i.e. inertial forces are small compared with viscous forces. The metachronal wavelength is also considered as very large for cilia induced MHD flow. Magnetic Reynolds number is sufficiently large to invoke magnetic induction effects. The physical problem is linearized and exact solutions are developed for the resulting boundary value problem. Closed-form expressions are presented for the stream function, pressure rise, induced magnetic field function and temperature. Mathematica symbolic software is used to compute and illustrate numerical results. The influence of physical parameters on velocity profile, pressure gradient and trapping of bolus are discussed with the aid of graphs. The present computations are applicable to simulations of flow control of in nano-magneto-biomimetic technologies

Advances in Heat and Mass Transfer in Micro/Nano Systems

The miniaturization of components in mechanical and electronic equipment has been the driving force for the fast development of micro/nanosystems. Heat and mass transfer are crucial processes in such systems, and they have attracted great interest in recent years. Tremendous effort, in terms of theoretical analyses, experimental measurements, numerical simulation, and practical applications, has been devoted to improve our understanding of complex heat and mass transfer processes and behaviors in such micro/nanosystems. This Special Issue is dedicated to showcasing recent advances in heat and mass transfer in micro- and nanosystems, with particular focus on the development of new models and theories, the employment of new experimental techniques, the adoption of new computational methods, and the design of novel micro/nanodevices. Thirteen articles have been published after peer-review evaluations, and these articles cover a wide spectrum of active research in the frontiers of micro/nanosystems

Recent Trends in Coatings and Thin Film–Modeling and Application

Over the past four decades, there has been increased attention given to the research of fluid mechanics due to its wide application in industry and phycology. Major advances in the modeling of key topics such Newtonian and non-Newtonian fluids and thin film flows have been made and finally published in the Special Issue of coatings. This is an attempt to edit the Special Issue into a book. Although this book is not a formal textbook, it will definitely be useful for university teachers, research students, industrial researchers and in overcoming the difficulties occurring in the said topic, while dealing with the nonlinear governing equations. For such types of equations, it is often more difficult to find an analytical solution or even a numerical one. This book has successfully handled this challenging job with the latest techniques. In addition, the findings of the simulation are logically realistic and meet the standard of sufficient scientific value

Science of Nanofluidics and Energy Conversion

The emerging subject of nanofluidics, where solids and fluids interact closely at the nanoscale, has exhibited radically different from their macroscopic counterparts (and sometimes counterintuitive), and yet relatively less explored. On the other hand, the resulting unique properties may contribute to a number of innovative functions with fascinating applications. Among various exciting potential applications, an important and ever expanding one is to provide alternative solutions to energy conversion with high efficiency, including energy absorption, actuation and harvesting. In this dissertation, we first report a novel protection mechanism of energy capture through which an intensive impact or blast energy can be effectively mitigated based on a nonwetting liquid-nanoporous material system. The captured energy is stored in nanopores in the form of potential energy of intercalated water molecules for a while, and not necessarily converted to other forms of energy (e.g. heat). At unloading stage, the captured energy will be released gradually due to the hydrophobic inner surfaces of nanopores through the diffusion of water molecules out of nanopores, thus making this system reusable. Several key controlling factors including impacting velocity, nanopore size, nanopore structure, and liquid phase have been investigated on the capacity of energy capture. The molecular mechanism is elucidated through the study of water molecular distributions inside nanpores. These molecular dynamic (MD) findings are quantitatively verified by a parallel blast experiment on a zeolite/water system. During the transport of confined liquid molecules, the friction resistance exerted by solid atoms of nanopores to liquid molecules will dissipate part of energy, and is highly dependent of temperature of liquid molecules and wall morphology of nanopores. Using MD simulations, the effects of temperature and wall roughness on the transport resistance of water molecules inside nanopores are investigated in Chapter 3. The effective shear stress and nominal viscosity that dominate the nanofluidic transport resistance are extracted and coupled with the nanopore size, transport rate, and liquid property. The molecular-level mechanisms are revealed through the study of the density profile and hydrogen bonding of confined liquid molecules. A parallel experiment on a nanoporous carbon-liquid system is carried out and qualitatively verifies MD findings. Motived by the well-known thermo- and electro-capillary effect, Chapter 4 and Chapter 5 present a conceptual design of thermal and electric actuation system by adjusting the relative hydrophobicity of a liquid-nanoporous system through a thermal and electric field, respectively. The thermally and electrically dependent infiltration behaviors of liquids into nanopores are analyzed by using MD simulations. The fundamental molecular characteristics, including the density profile, contact angle, and surface tension of the confined liquid molecules, are examined to reveal underlying mechanisms. The energy density, power density, and efficiency of both thermal and electric actuation systems are explored and their variations with pore size, solid phase, and liquid phase are evaluated. Thermally and electrically controlled infiltration experiments on a zeolite-water /electrolyte solution system are performed accordingly to qualitatively validate these findings. These energy actuation systems can also become high density thermal or electric storage devices with proper designs. Energy harvesting by the flow of a hydrochloric acid-water solution through a nanopore is explored using atomistic simulations in the last chapter. Through ion configurations near the pore wall, an averaged ion drifting velocity is determined, and the induced voltage along the axial direction is obtained as a function of key material parameters, including the applied flow rate, environmental temperature, solution concentration and nanopore size. The molecular mechanism of ion hopping and motion is revealed. This study shed light on harvesting wasted thermal and mechanical energy from ambient environmental sources such as wasted heat in power plants. Nanofluidics is a novel and thriving research area, whose couplings with other disciplines such as material, mechanical, physical, chemical, electrical engineering are open

A review of novel heat transfer materials and fluids for aerospace applications

The issue of thermal control for space missions has been critical since the early space missions in the late 1950s. The demands in such environments are heightened, characterized by significant temperature variations and the need to manage substantial densities of heat. The current work offers a comprehensive survey of the innovative materials and thermal fluids employed in the aerospace technological area. In this scope, the materials should exhibit enhanced reliability for facing maintenance and raw materials scarcity. The improved thermophysical properties of the nanofluids increase the efficiency of the systems, allowing the mass/volume reduction in satellites, rovers, and spacecraft. Herein are summarized the main findings from a literature review of more than one hundred works on aerospace thermal management. In this sense, relevant issues in aerospace convection cooling were reported and discussed, using heat pipes and heat exchangers, and with heat transfer ability at high velocity, low pressure, and microgravity. Among the main findings, it could be highlighted the fact that these novel materials and fluids provide enhanced thermal conductivity, stability, and insulation, enhancing the heat transfer capability and preventing the malfunctioning, overheating, and degradation over time of the systems. The resulting indicators will contribute to strategic mapping knowledge and further competence. Also, this work will identify the main scientific and technological gaps and possible challenges for integrating the materials and fluids into existing systems and for maturation and large-scale feasibility for aerospace valorization and technology transfer enhancement.This work has been funded by FCT/MCTES (PIDDAC) through the base funding from the following research units: UIDP/50009/2020-FCT and UIDB/50009/2020-FCT, UIDB/00532/2020, LA/P/0045/2020, UIDB/04077/2020, and UIDP/04077/2020. The authors are also grateful for FCT funding through 2022. 03151.PTDC, PTDC/EME-TED/7801/2020, POCI-01-0145-FEDER-016861, POCI-01-0145-FEDER-028159, 2022. 02085.PTDC (https://doi.org/10.54499/2022.02085.PTDC, accessed on 25 March 2024), funded by COMPETE2020, NORTE2020, PORTUGAL2020, and FEDER. Glauco Nobrega was supported by the doctoral grant PRT/BD/153088/2021, financed by the Portuguese Foundation for Science and Technology (FCT), under the MIT Portugal Program. Pinho D. and Susana O. Catarino thank FCT for her contract funding provided through 2021.00027.CEECIND, 2020.00215.CEECIND (DOI: https://doi.org/10.54499/2020.00215.CEECIND/CP1600/CT0009, accessed on 25 March 2024), respectively. The authors are also grateful to the Fundação para a Ciência e a Tecnologia (FCT), Avenida D. Carlos I, 126, 1249–074 Lisboa, Portugal, for partially financing the Project “Estratégias interfaciais de arrefecimento para tecnologias de conversão com elevadas potências de dissipação”, ref. PTDC/EMETED/7801/2020, Associação do Instituto Superior Técnico para a Investigação e o Desenvolvimento (IST-ID). José Pereira also acknowledges FCT for his PhD fellowship (Ref. 2021. 05830.BD). The authors are also grateful for FCT funding through 2022.03151.PTD and LA/P/0083/2020 IN + -IST-ID. The authors are also grateful for FCT funding through 2022.03151.PTD and LA/P/0083/2020 IN + -IST-ID and through UIPD/50009/2020-FCT and UIDB/50009—FCT. Ana Moita also acknowledges FCT for partially financing her contract through CEECINST/00043/2021/CP2797/CT0005, doi:https://doi.org/10.54499/CEECINST/00043/2021/CP2797/CT0005, accessed on 25 March 2024. The authors also acknowledge Exército Português for their support through projects CINAMIL Desenvolvimento de Sistemas de Gestão Térmica e Climatização de equipamento NBQ and COOLUAV—Sistema de arrefecimento da componente eletrónica e baterias em veículos militares não tripulados

Advances in Microfluidic Technologies for Energy and Environmental Applications

Microfluidics have aroused a new surge of interest in recent years in environmental and energy areas, and inspired novel applications to tackle the worldwide challenges for sustainable development. This book aims to present readers with a valuable compendium of significant advances in applying the multidisciplinary microfluidic technologies to address energy and environmental problems in a plethora of areas such as environmental monitoring and detection, new nanofluid application in traditional mechanical manufacturing processes, development of novel biosensors, and thermal management. This book will provide a new perspective to the understanding of the ever-growing importance of microfluidics

Convective heat transfer for Peristaltic flow of SWCNT inside a sinusoidal elliptic duct

A mathematical model is presented to analyse the flow characteristics and heat transfer aspects of a heated Newtonian viscous fluid with single wall carbon nanotubes inside a vertical duct having elliptic cross section and sinusoidally fluctuating walls. Exact mathematical computations are performed to get temperature, velocity and pressure gradient expressions. A polynomial solution technique is utilized to obtain these mathematical solutions. Finally, these computational results are presented graphically and different characteristics of peristaltic flow phenomenon are examined in detail through these graphs. The velocity declines as the volume fraction of carbon nanotubes increases in the base fluid. Since the velocity of fluid is dependent on its temperature in this study case and temperature decreases with increasing volumetric fraction of carbon nanotubes. Thus velocity also declines for increasing volumetric fraction of nanoparticles

Computation of reactive thermosolutal micropolar nanofluid Sakiadis convection flow with gold/silver metallic nanoparticles

In the present study, a mathematical model is developed by combining the Tiwari-Das nanofluidformulation with the Eringen micro-morphic model to simulate the thermo-solutal natural convection chemicallyreacting micropolar nanofluid flow from a permeable stretching surface with non-uniform heat source/sink effects.The transformed ordinary differential equation boundary value problem features linear momentum, angularmomentum, energy and species conservation boundary layer equations with appropriate boundary conditions.This ninth order nonlinear system is solved with Runge-Kutta 45 Fehlberg method (Maple dsolve routine).Several nanoparticles i.e., gold, and silver with aqueous base fluid are studied. The influence of the effect of theemerging parameters on the velocity, angular velocity, temperature, nanoparticle concentration, skin friction,couple stress, Nusselt number and Sherwood number distributions are visualized and tabulated. It is observed thatIncreasing volume fraction decreases velocity whereas it elevates microrotation, temperature and nanoparticleconcentration. Nanoparticle concentrations are elevated for stronger destructive chemical reaction effect whereasthey are suppressed with constructive chemical reaction. With greater micropolar boundary condition parameter,the velocity is elevated, microrotation but reduces temperature and thermal boundary layer thickness. Increasingnanoparticle volume fraction enhances both skin friction and couple stress but marginally reduces the Nusseltnumber. Finally, Au-water micropolar nanofluids achieve the highest skin friction and couple stress magnitudes,then Ag-water and finally Cu-water. Validation of solutions with earlier non-reactive studies in the absence ofnanoparticle mass transfer are included

Advances in Microfluidic Technologies for Energy and Environmental Applications

Microfluidics have aroused a new surge of interest in recent years in environmental and energy areas, and inspired novel applications to tackle the worldwide challenges for sustainable development. This book aims to present readers with a valuable compendium of significant advances in applying the multidisciplinary microfluidic technologies to address energy and environmental problems in a plethora of areas such as environmental monitoring and detection, new nanofluid application in traditional mechanical manufacturing processes, development of novel biosensors, and thermal management. This book will provide a new perspective to the understanding of the ever-growing importance of microfluidics

Modeling and Simulation in Engineering

The Special Issue Modeling and Simulation in Engineering, belonging to the section Engineering Mathematics of the Journal Mathematics, publishes original research papers dealing with advanced simulation and modeling techniques. The present book, “Modeling and Simulation in Engineering I, 2022”, contains 14 papers accepted after peer review by recognized specialists in the field. The papers address different topics occurring in engineering, such as ferrofluid transport in magnetic fields, non-fractal signal analysis, fractional derivatives, applications of swarm algorithms and evolutionary algorithms (genetic algorithms), inverse methods for inverse problems, numerical analysis of heat and mass transfer, numerical solutions for fractional differential equations, Kriging modelling, theory of the modelling methodology, and artificial neural networks for fault diagnosis in electric circuits. It is hoped that the papers selected for this issue will attract a significant audience in the scientific community and will further stimulate research involving modelling and simulation in mathematical physics and in engineering