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Transient peristaltic diffusion of nanofluids: A model of micropumps in medical engineering

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Journal of Hydrodynamics 2018年第6期30卷 1001-1011页

作者： Dharmendra Tripathi Shashi Bhushan O.Anwar Bég Noreen Sher Akbar Department of Science and Humanities National Institute of TechnologyUttarakhand–246174 India Department of Mechanical Engineering Manipal University Department of Aeronautical and Mechanical Engineering University of Salford DBS & H CEME National University of Sciences and TechnologyIslamabad Pakistan

Peristaltic micro-pumps offer an excellent mechanism for delivery of a variety of medicines including drugs, corneal solutions etc. The surge in deployment of nanoparticles in medicine has provided new potential for such pumps. In light of this we investigate the time-dependent peristaltic flow of nanofluids with diffusive effects through a finite non-uniform channel, this geometry being more representative of real micro-pumps. Creeping flow is taken into account(inertial forces are small compared with viscous forces) i.e., Reynolds number is low(Renanofluids is employed with an Oberbeck-Boussinesq approximation. Closed-form solutions are developed for the non-dimensional governing equations subject to physically realistic boundary conditions. Mathematica symbolic software is employed to evaluate the evolution of nanoparticle fraction, temperature, axial velocity, transverse velocity and pressure difference distribution along the length of the pump channel with variation in thermal Grashof number, basic-density(species i.e., mass) Grashof number, Brownian motion parameter and thermophoresis parameter.

关键词： Unsteady flow peristaltic pumps nanofluids medical engineering diffusive process grashof number thermophoresis

Effects on the Phase Transformation Temperature of nanofluids by the Nanoparticles

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Journal of Materials Science & Technology 2008年第5期24卷 742-744页

作者： Huaqing XIE Jifen WAN Lifei CHEN Department of Environmental Engineering Shanghai Second Polytechnic University Shanghai 201209 China

nanofluids have been demonstrated to have intriguing thermodynamic properties. In this work, we described the investigation of the phase transformation behaviors of nanofluids containing alumina （Al2O3） or titania （TiO2） nanoparticles with different weight fractions. The experimental results indicate that the melting temperatures of nanofluids （in freezing states） are reduced with the increase of the weight fraction of nanoparticles. The reduction is related to nanoparticle species as well as nanoparticle size.

关键词： nanofluids Thermal analysis Melting

ZnO nanofluids-A potential antibacterial agent

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Progress in Natural Science:Materials International 2008年第8期18卷 939-944页

作者： Malcolm Povey David York Procter Department of Food Science University of Leeds Leeds LS2 9JT UK Procter and Gamble Newcastle Technical Centre Newcastle-upon-Tyne NE12 9TS UK

In this work, ZnO nanofluids were produced by a medium mill with a pH value of about 7.2 and characterized by Nano-Sizer and SEM. After milling, ZnO nanofluids were formed with an average particle size of 198.4 nm. The ZnO nanofluids used for testing were stored for different periods (1-, 90- and 120-day) and kept in different conditions (under the light and in the dark). The antibacterial activities of these ZnO nanofluids were evaluated by estimating the reduction ratio of the bacteria treated with ZnO. The results showed that the ZnO nanofluid stored for 120 days under the light had the best antibacterial behavior against Escherichia coli DH5a. SEM images suggest that an interaction between the ZnO particles and the E. coli bacteria cells caused by electrostatic forces might be a mechanism.

关键词： Antibacterial nanofluids ZnO E. coli Photocatalysis

Analysis of flow and heat transfer characteristics of micro-pin fin heat sink using silver nanofluids

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Science China(Technological Sciences) 2012年第1期55卷 155-162页

作者： ZHOU MingZheng XIA GuoDong CHAI Lei LI Jian ZHOU LiJun Key Laboratory of Enhanced Heat Transfer and Energy Conservation Ministry of Education College of Environmental and Energy Engineering Beijing University of Technology Beijing 100124 China

Silver nanofluids with three different volume fractions are prepared by a one-step chemical reduction method(Ultra-sound-assisted Membrane Reaction(UAMR)).The convective heat transfer and friction characteristics of silver nanofluid in micro-pin fin heat sink are investigated experimentally.The results indicate that the pressure drops of nanofluids with different volume fractions have little difference.Compared to the base fluid(polyvinylpyrrolidone(PVP) solution),the pressure drop of nanofluids increases slightly at the same volume flow rate.When the flow rate is small,the increment is not obvious.The in-troduction of surfactant increases the fluid viscosity,so the pressure drops of nanofluids are larger than those of pure water,under the same flow rate.However,the maximum difference is no more than 10%.The volume fraction of silver nanoparticles significantly affects the convection heat transfer coefficient of micro-pin fin heat sink.The presence of nanoparticles improves significantly the heat transfer performance.However,high viscosity of the nanofluids hinders the heat transfer strengthening effect of nanofluids.In the present work,when the volume fraction of silver particles reaches to 0.012%,the thermal resistance of nanofluid gradually becomes lower than that of deionized water,which indicates the integrated heat transfer enhancement of nanofluids.

关键词： nanofluids 微大头针的鳍热转移粘性体积部分

Hybrid Effects of Thermal and Concentration Convection on Peristaltic Flow of Fourth Grade nanofluids in an Inclined Tapered Channel: Applications of Double-Diffusivity

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Computer Modeling in Engineering & Sciences 2021年第6期127卷 901-922页

作者： Safia Akram Alia Razia MCS National University of Sciences and TechnologyIslamabadPakistan

This article brings into focus the hybrid effects of thermal and concentration convection on peristaltic pumping of fourth grade nanofluids in an inclined tapered channel.First,the brief mathematical modelling of the fourth grade nanofluids is provided along with thermal and concentration convection.The Lubrication method is used to simplify the partial differential equations which are tremendously nonlinear.Further,analytical technique is applied to solve the differential equations that are strongly nonlinear in nature,and exact solutions of temperature,volume fraction of nanoparticles,and concentration are studied.Numerical and graphical findings manifest the influence of various physical flow-quantity parameters.It is observed that the nanoparticle fraction decreases because of the increasing values of Brownian motion parameter and Dufour parameter,whereas the behaviour of nanoparticle fraction is quite opposite for thermophoresis parameter.It is also noted that the temperature profile decreases with increasing Brownian motion parameter values and rises with Dufour parameter values.Moreover,the concentration profile ascends with increasing thermophoresis parameter and Soret parameter values.

关键词： nanofluids thermal and concentration convection peristaltic flow inclined tapered channel fourth grade fluid

Preparation and stabilization mechanism of carbon dots nanofluids for drag reduction

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Petroleum Science 2020年第6期17卷 1717-1725页

作者： Yi-Ning Wu Yuan Li Meng-Jiao Cao Cai-Li Dai Long He Yu-Ping Yang Shandong Key Laboratory of Oilfi eld Chemistry School of Petroleum EngineeringChina University of Petroleum(East China)Qingdao 266580China Petroleum Engineering Institute Northwest Branch of SinopecUrumchi 830000China CNPC Engineering Technology R&D Company Limited Beijing 100007China

During the development of low or ultra-low permeability oil resources,the alternative energy supply becomes a prominent issue.In recent years,carbon dots(CDs)have drawn much attention owing to their application potential in oil fields for reducing injection pressure and augmenting oil recovery.However,carbon dots characterized of small size,high surface energy are faced with several challenges,such as self-aggregation and settling.The preparation of stably dispersed carbon dots nanofluids is the key factor to guarantee its application performance in formation.In this work,we investigated the stability of hydrophilic carbon dots(HICDs)and hydrophobic carbon dots-Tween 80(HOCDs)nanofluids.The influences of carbon dots concentration,sorts and concentration of salt ions as well as temperature on the stability of CDs were studied.The results showed that HICDs are more sensitive to sort and concentration of salt ions,while HOCDs are more sensitive to temperature.In addition,the core flooding experiments demonstrated that the pressure reduction rate of HICDs and HOCDs nanofluids can be as high as 17.88%and 26.14%,respectively.Hence,the HICDs and HOCDs nanofluids show a good application potential in the reduction of injection pressure during the development of low and ultra-low permeability oil resources.

关键词： Carbon dots nanofluids Drag reduction Stabilization mechanism Salt tolerance

Numerical Investigation and Optimization of a Flat Plate Solar Collector Operating with Cu/CuO/Al_(2)O_(3)–Water nanofluids

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Transactions of Tianjin University 2021年第1期27卷 64-76页

作者： Youssef Belkassmi Kamal Gueraoui Lahoucine El maimouni Najem Hassanain Omar Tata ERMAM Polydisciplinary Faculty of OuarzazateIbn Zohr UniversityBox 638OuarzazateMorocco MSME Faculty of SciencesMohammed-V UniversityRabatMorocco Group of Semiconductors and Environmental Sensor Technologies-Energy Research Center Faculty of ScienceMohammed-V UniversityB.P.1014RabatMorocco GEMS Laboratory ENSAIbn Zohr UniversityB.P.1136AgadirMorocco

nanofluids are a potential alternative to significantly improving the performance of heat transfer applications. In this work, a numerical analysis to examine the eff ect of dispersing copper(Cu), copper oxide(CuO), and aluminum(Al2O3) nanoparticles in pure water on the performance of a flat plate solar collector(FPSC) and a numerical model was proposed. The influence of the nanofluid type on the thermal efficiency was critically investigated and discussed. The eff ect of the mass flow rate on the performance was also analyzed and discussed. Based on correlations of the thermophysical properties of nanofluids, a sensitivity analysis was used to analyze the impact of the nanoparticles on the base fluid. The results indicate that the performance of the FPSC with Cu/water nanofluid was better than that of FPSCs using CuO/water or Al2O3/water nanofluids. When the mass flow rate of the nanofluids was 8.0 L/min, the efficiency of the FPSC was much greater than those at the flow rates of 5.0 L/min and 2.0 L/min. Mean enhancements in thermal efficiency of 4.44%, 4.27%, and 4.21% were observed when 2.0 L/min was applied using Cu/water, Cu O/water, and Al2O3/water nanofluids, respectively. Improvements in thermal efficiency of 2.76%, 2.53%, and 2.47% occurred when 8.0 L/min was applied.

关键词： Flat plate solar collector Solar energy Thermal efficiency nanofluids Al_2O_3/water Cu/water CuO/water

Thermal Analysis of MHD Non-Newtonian nanofluids over a Porous Media

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Computer Modeling in Engineering & Sciences 2020年第12期125卷 1119-1134页

作者： Asad Ejaz Imran Abbas Yasir Nawaz Muhammad Shoaib Arif Wasfi Shatanawi Javeria Nawaz Abbasi Stochastic Analysis&Optimization Research Group Department of MathematicsAir UniversityIslamabad44000Pakistan Department of Mathematics and General Sciences Prince Sultan UniversityRiyadh11586Saudi Arabia Department of Medical Research China Medical University HospitalChina Medical UniversityTaichung40402TaiwanChina Department of Mathematics Hashemite UniversityZarqa13116Jordan Department of Mathematics Comsats UniversityIslamabad44000Pakistan

In the present research,Tiwari and Das model are used for the impact of a magnetic field on non-Newtonian nanofluid flow in the presence of injection and suction.The PDEs are converted into ordinary differential equations(ODEs)using the similarity method.The obtained ordinary differential equations are solved numerically using shooting method along with RK-4.Part of the present study uses nanoparticles(NPs)like TiO_(2) andAl_(2)O_(3) and sodium carboxymethyl cellulose(CMC/water)is considered as a base fluid(BF).This study is conducted to find the influence of nanoparticles,Prandtl number,and magnetic field on velocity and temperature profile,however,the Nusselt number and coefficient of skin friction parameters are also presented in detail with the variation of nanoparticles and parameters.The obtained results of the present study are presented usingMATLAB.In addition to these,some simulations of partial differential equations are also shown using software for graphing surface plots of velocity profile and streamlines along with surface plots and isothermal contours of the temperature profile.

关键词： MHD non-Newtonian nanofluids porous medium similarity solution Blasius flow

Experimental Evaluation of Thermal Conductivity and Other Thermophysical Properties of nanofluids Based on Functionalized (-OH) Mwcnt Nanoparticles Dispersed in Distilled Water

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Advances in Nanoparticles 2023年第1期12卷 32-52页

作者： Alexandre Melo Oliveira Amir Zacarias Mesquita João Gabriel de Oliveira Marques Enio Pedone Bandarra Filho Daniel Artur Pinheiro Palma Federal Institute of Sã o Paulo (IFSP) S&atildeo Carlos Brazil Nuclear Technology Development Center (CDTN) Belo Horizonte Brazil Federal University of Uberlandia (UFU) Uberlandia Brazil Brazilian Nuclear Energy Comission Rio de Janeiro Brazil

A possible way to increase thermal conductivity of working fluids, while keeping pressure drop at acceptable levels, is through nanofluids. nanofluids are nano-sized particles dispersed in conventional working fluids. A great number of materials have potential to be used in nanoparticles production and then in nanofluids;one of them is Multi-Walled Carbon Nano Tubes (MWCNT). They have thermal conductivity around 3000 W/mK while other materials used as nanoparticles like CuO have thermal conductivity of 76.5 W/mK. Due to this fact, MWCNT nanoparticles have potential to be used in nanofluids production, aiming to increase heat transfer rate in energy systems. In this context, the main goal of this paper is to evaluate from the synthesis to the experimental measurement of thermal conductivity of nanofluid samples based on functionalized (-OH) MWCNT nanoparticles. They will be analyzed nanoparticles with different functionalization degrees (4% wt, 6% wt, and 9% wt). In addition, it will be quantified other thermophysical properties (dynamic viscosity, specific heat and specific mass) of the synthetized nanofluids. So, the present work can contribute with experimental data that will help researches in the study and development of MWCNT nanofluids. According to the results, the maximum increment obtained in thermal conductivity was 10.65% in relation to the base fluid (water).

关键词： nanofluids Multi-Walled Carbon Nano Tubes (MWCNT) Functionalization Degree Thermal Conductivity Thermophysical Properties