DOCSLIB.ORG

Investigation on Thermal Conductivity, Viscosity and Stability of Nanofluids

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Investigation on Thermal Conductivity, Viscosity and Stability of Nanofluids Investigation on Thermal Conductivity, Viscosity and Stability of Nanofluids Mohammadreza Behi Seyed Aliakbar Mirmohammadi Master of Science Thesis Royal Institute of Technology (KTH) School of Industrial Engineering and Management Department of Energy Technology Division of Applied Thermodynamics and Refrigeration Stockholm, Sweden Master of Science Thesis EGI-2012 Investigation on Thermal Conductivity, Viscosity and Stability of Nanofluids Mohammadreza Behi Seyed Aliakbar Mirmohammadi Approved Examiner Supervisor 15.06.2012 Björn Palm Ehsan Bitaraf Haghighi Rahmatollah Khodabandeh Commissioner Contact person II Abstract In this thesis, two important thermo-physical properties of nanofluids: thermal conductivity and viscosity together with shelf stability of them are investigated. Nanofluids are defined as colloidal suspension of solid particles with the size of lower than 100 nanometer. Thermal conductivity, viscosity and stability of nanofluids were measured by means of TPS method, rotational method and sedimentation balance method, respectively. TPS analyzer and viscometer were calibrated in the early stage and all measured data were in the reasonable range. Effect of some parameters including temperature, concentration, size, shape, alcohol addition and sonication time has been studied on thermal conductivity and viscosity of nanofluids. It has been concluded that increasing temperature, concentration and sonication time can lead to thermal conductivity enhancement while increasing amount of alcohol can decrease thermal conductivity of nanofluids. Generally, tests relating viscosity of nanofluids revealed that increasing concentration increases viscosity; however, increasing other investigated parameters such as temperature, sonication time and amount of alcohol decrease viscosity. In both cases, increasing size of nanofluid results in thermal conductivity and viscosity reduction up to specific size (250 nm) while big particle size (800 nm) increases thermal conductivity and viscosity, drastically. In addition, silver nanofluid with fiber shaped nanoparticles showed higher thermal conductivity and viscosity compared to one with spherical shape nanoparticles. Furthermore, effect of concentration and sonication time have been inspected on stability of nanofluids. Test results indicated that increasing concentration speeds up sedimentation of nanoparticles while bath sonication of nanofluid brings about lower weight for settled particles. Considering relative thermal conductivity to relative viscosity of some nanofluids exposes that ascending or descending behavior of graph can result in some preliminary evaluation regarding applicability of nanofluids as coolant. It can be stated that ascending trend shows better applicability of the sample in higher temperatures while it is opposite for descending trend. Meanwhile, it can be declared that higher value for this factor shows more applicable nanofluid with higher thermal conductivity and less viscosity. Finally, it has been shown that sedimentation causes reduction of thermal conductivity as well as viscosity. For further research activities, it would be suggested to focus more on microscopic investigation regarding behavior of nanofluids besides macroscopic study. III Acknowledgment There are so many people that we would like to thank due to their support, encouragement, and assistance. Firstly, we should sincerely express our great gratitude to Professor Björn Palm for his enormous patience, sophisticated comments, consistent support, and make the possibility for us to work at ETT laboratory of Energy Department of KTH and acquire very nice experiences. We would also like to thank Dr. Rahmatollah Khodabandeh due to his support and kindness during our thesis work. Very special thanks go to Ehsan Bitaraf Haghighi who played a significant role in our thesis work and opened doors of nanotechnology science for us. He was not only an excellent supervisor with great energy all day long, but also a very gentle friend. Ehsan, without your support and constructive suggestions it was impossible for us to end up with this much work. We thank two nice friends, Zahid Anwar and Joan Iborra Rubio for making a nice atmosphere in the lab. Furthermore, thanks go to Benny Sjöberg, Peter Hill, Dr. Åke Melinder and the entire faculty at the Department of Energy Technology. We want to thank NanoHex partners for providing us samples and relevant required data, especially Mohsin Salimi and Nader Niknam from Department of Material Sciences (KTH Kista campus). We also would like to thank two of our proficient friends, Marjan Akram and Mahmood Kaboosi for editing the report and providing some figures. The last but not the least, we would like to thank our parents, brothers and sister for supporting us during the whole life, especially during our study abroad in Sweden. Without their encouragement and help, it would not be possible for sure. IV List of Figures Figure 1.1: Common basefluids, nanoparticles, and surfactants for synthesizing nanofluid.......................... 3 Figure 2.1: Share of different methods in literature......................................................................................... 11 Figure 2.2: Schematic of transient hot-wire experimental setup ....................................................................11 Figure 2.3: Schematic of transient temperature oscillation technique ........................................................... 13 Figure 2.4: Falling ball viscometers schematic..................................................................................................19 Figure 2.5: Falling ball viscometers schematic..................................................................................................20 Figure 2.6: Coaxial cylinder viscometers schematic......................................................................................... 21 Figure 2.7: Three bubble viscometers in different viscosity ranges................................................................ 22 Figure 3.1: Experimental setup of Transient Plane Source (TPS) method .................................................... 28 Figure 3.2: Sample holder and sensor ...............................................................................................................29 Figure 3.3: Thermal conductivity of water at different temperatures............................................................. 29 Figure 3.4: Thermal conductivity of ethylene glycol (EG) at different temperatures ................................... 30 Figure 3.5: Thermal conductivity of mixture of ethylene glycol and distilled water (50 vol%) at different temperatures........................................................................................................................................................ 31 Figure 3.7: Location of seven thermocouples installed in thermal bath......................................................... 32 Figure 3.8: Temperature monitoring of bath and sample holder over the time at T=20oC for dry shell...33 Figure 3.9: Average temperature of clamp, shell and bath compared to adjusted temperature at T=20oC for dry shell.......................................................................................................................................................... 33 Figure 3.10: Temperature monitoring of bath and sample holder over the time from T=20oC to T=30oC for dry shell.......................................................................................................................................................... 34 Figure 3.11: Temperature monitoring of bath and sample holder over the time at T=30oC for dry shell . 34 Figure 3.12: Average temperature of clamp, shell and bath compared to adjusted temperature at T=30oC for dry shell.......................................................................................................................................................... 35 Figure 3.13: Temperature difference from set point for dry shell ..................................................................36 Figure 3.14: Temperature monitoring of bath and sample holder over the time at T=20oC for wet shell. 36 Figure 3.15: Average temperature of clamp, shell and bath compared to adjusted temperature at T=20oC for wet shell ........................................................................................................................................................37 Figure 3.16: Temperature monitoring of bath and sample holder over the time from T=20oC to T=30oC for wet shell ........................................................................................................................................................37 Figure 3.17: Temperature monitoring of bath and sample holder over the time at T=30oC for wet shell. 38 Figure 3.18: Temperature difference from set point for wet shell..................................................................39 Figure 3.19: Temperature difference from set point for dry and wet shell at different temperatures......... 39 Figure 3.20: Temperature monitoring of sample holder over the time from T=20oC to T=30oC for wet and dry shells.......................................................................................................................................................40 Figure 3.21: Hot Disk sensor with Kapton insulation..................................................................................... 41 Figure 3.22: Power/Time combinations for
Load more

Recommended publications
  • Cfd and Experimental Investigation on the Heat Transfer Characteristics of Alumina Nanofluids Under the Laminar Flow Regime
    Brazilian Journal of Chemical ISSN 0104-6632 Printed in Brazil Engineering www.abeq.org.br/bjche Vol. 31, No. 02, pp. 469 - 481, April - June, 2014 dx.doi.org/10.1590/0104-6632.20140312s00001959 CFD AND EXPERIMENTAL INVESTIGATION ON THE HEAT TRANSFER CHARACTERISTICS OF ALUMINA NANOFLUIDS UNDER THE LAMINAR FLOW REGIME A. Azari1, M. Kalbasi1* and M. Rahimi2 1Department of Petrochemical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Mahshahr Campus, Mahshahr, P.O. Box 415, Iran. Phone/Fax: + 98-65223-43645. E-mail: [email protected]; [email protected] 2CFD Research Center, Chemical Engineering Department, Razi University, TagheBostan, Kermanshah, Iran. (Submitted: May 22, 2012 ; Revised: November 3, 2012 ; Accepted: June 24, 2013) Abstract - This study reports experimental and Computational Fluid Dynamics (CFD) investigations of the laminar convective heat transfer coefficient of Al2O3/water nanofluids in a circular tube under uniform and constant heat flux on the wall. Three different models including a constant physical properties single-phase (CP-SP) model, a variable physical properties single-phase (VP-SP) model and a discrete particles two-phase model were developed. Particle agglomeration and cluster size distribution were considered in the two-phase model. Experimental and simulation results showed that the thermal performance of nanofluids is higher than that of the base fluid and the heat transfer enhancement increases with the particle volume concentration and Reynolds number. Furthermore, higher heat transfer coefficients were detected in the case of the VP-SP model and the two-phase model. The results demonstrated that the two-phase model prediction and experimental data match significantly and that the model can be employed with confidence for the prediction of any type of nanofluid.
    [Show full text]
  • Effect of Glass Transition: Density and Thermal Conductivity Measurements of B2O3
    High Temperatures-High Pressures, Vol. 49, pp. 125–142 ©2020 Old City Publishing, Inc. Reprints available directly from the publisher Published by license under the OCP Science imprint, Photocopying permitted by license only a member of the Old City Publishing Group DOI: 10.32908/hthp.v49.801 Effect of glass transition: density and thermal conductivity measurements of B2O3 DMITRY CHEBYKIN1*, HANS-PETER HELLER1, IVAN SAENKO2, GERT BARTZSCH1, RIE ENDO3 AND OLENA VOLKOVA1 1Institute of Iron and Steel Technology, TU Bergakademie Freiberg, Leipziger Straße 34, 09599 Freiberg, Germany 2Institute of Materials Science, TU Bergakademie Freiberg, Gustav-Zeuner-Straße 5, 09599 Freiberg, Germany 3Department of Materials Science and Engineering, Tokyo Institute of Technology, 152–8552 Tokyo, Japan Received: May 28, 2019; Accepted: October 11, 2019. The role of B2O3 as a fluxing agent for developing fluoride free fluxes has been accentuated in the recent years. Therefore, knowledge about thermo- physical properties of the oxide are essential to find the optimal chemical composition of the mold fluxes. In the present study, the density and ther- mal conductivity of B2O3 were measured by means of the buoyancy method, the maximal bubble pressure (MBP) method and the hot-wire method in the temperature range of 295–1573 K. The results are discussed in the context of the chemical stability of the B2O3 as well as the effect of glass transition on the thermal conductivity. The density of the B2O3 decreases non-linearly with increasing temperature in the temperature range of 973–1573 K. The MBP method was successfully applied for the density measurements with a viscosity up to 91 Pa.s.
    [Show full text]
  • R09 SI: Thermal Properties of Foods
    Related Commercial Resources CHAPTER 9 THERMAL PROPERTIES OF FOODS Thermal Properties of Food Constituents ................................. 9.1 Enthalpy .................................................................................... 9.7 Thermal Properties of Foods ..................................................... 9.1 Thermal Conductivity ................................................................ 9.9 Water Content ........................................................................... 9.2 Thermal Diffusivity .................................................................. 9.17 Initial Freezing Point ................................................................. 9.2 Heat of Respiration ................................................................. 9.18 Ice Fraction ............................................................................... 9.2 Transpiration of Fresh Fruits and Vegetables ......................... 9.19 Density ...................................................................................... 9.6 Surface Heat Transfer Coefficient ........................................... 9.25 Specific Heat ............................................................................. 9.6 Symbols ................................................................................... 9.28 HERMAL properties of foods and beverages must be known rizes prediction methods for estimating these thermophysical proper- Tto perform the various heat transfer calculations involved in de- ties and includes examples on the
    [Show full text]
  • THERMAL CONDUCTIVITY of CONTINUOUS CARBON FIBRE REINFORCED COPPER MATRIX COMPOSITES J.Koráb1, P.Šebo1, P.Štefánik 1, S.Kavecký 1 and G.Korb 2
    1. THERMAL CONDUCTIVITY OF CONTINUOUS CARBON FIBRE REINFORCED COPPER MATRIX COMPOSITES J.Koráb1, P.Šebo1, P.Štefánik 1, S.Kavecký 1 and G.Korb 2 1 Institute of Materials and Machine Mechanics of the Slovak Academy of Sciences, Racianska 75, 836 06 Bratislava, Slovak Republic 2 Austrian Research Centre Seibersdorf, A-2444 Seibersdorf, Austria SUMMARY: The paper deals with thermal conductivity of the continuous carbon fibre reinforced - copper matrix composite that can be applied in the field of electric and electronic industry as a heat sink material. The copper matrix - carbon fibre composite with different fibre orientation and fibre content was produced by diffusion bonding of copper-coated carbon fibres. Laser flash technique was used for thermal conductivity characterisation in direction parallel and transverse to fibre orientation. The results revealed decreasing thermal conductivity as the volume content of fibre increased and independence of through thickness conductivity on fibre orientation. Achieved results were compared with the materials that are currently used as heat sinks and possibility of the copper- based composite application was analysed. KEYWORDS: thermal conductivity, copper matrix, carbon fibre, metal matrix composite, heat sink, thermal management, heat dissipation INTRODUCTION Carbon fibre reinforced - copper matrix composite (Cu-Cf MMC) offer thermomechanical properties (TMP) which are now required in electronic and electric industry. Their advantages are low density, very good thermal conductivity and tailorable coefficient of thermal expansion (CTE). These properties are important in the applications where especially thermal conductivity plays large role to solve the problems of heat dissipation due to the usage of increasingly powerful electronic components. In devices, where high density mounting technology is applied thermal management is crucial for the reliability and long life performance.
    [Show full text]
  • Magnetic Nanofluid Properties As the Heat Transfer Enhancement Agent
    E3S Web of Conferences 10, 00111 (2016) DOI: 10.1051/e3sconf/20161000111 SEED 2016 Magnetic nanofluid properties as the heat transfer enhancement agent Aleksandra Roszko1,a and Elzbieta Fornalik-Wajs1 1AGH University of Science and Technology, Department of Fundamental Research in Energy Engineering, 30 Mickiewicz Ave., 30-059 Krakow, Poland Abstract. The main purpose of this paper was to investigate an influence of various parameters on the heat transfer processes with strong magnetic field utilization. Two positions of experimental enclosure in magnetic environment, two methods of preparation and three different concentrations of nanoparticles (0.0112, 0.056 and 0.112 vol.%) were taken into account together with the magnetic field strength. Analysed nanofluids consisted of distilled water (diamagnetic) and Cu/CuO particles (paramagnetic) of 40-60 nm size. The nanofluids components had different magnetic properties what caused complex interaction of forces’ system. The heat transfer data and fluid flow structure demonstrated the influence of magnetic field on the convective phenomena. The most visible consequence of magnetic field application was the heat transfer enhancement and flow reorganization under applied conditions. 1 Introduction and three different concentrations of nanoparticles (0.0112, 0.056 and 0.112 vol.%) were taken into account Regarding the forthcoming thermo-ecological together with the magnetic field strength. The fluctuations requirements there are a lot of issues devoted of temperature field were analyzed by Fast Fourier to improvement of existing technologies, increasing Transform and spectral analysis what led the efficiencies, emissions reduction, looking for a new devices and systems. In industrial applications increasing to the understanding of flow behavior under applied conditions.
    [Show full text]
  • Carbon Epoxy Composites Thermal Conductivity at 77 K and 300 K Jean-Luc Battaglia, Manal Saboul, Jérôme Pailhes, Abdelhak Saci, Andrzej Kusiak, Olivier Fudym
    Carbon epoxy composites thermal conductivity at 77 K and 300 K Jean-Luc Battaglia, Manal Saboul, Jérôme Pailhes, Abdelhak Saci, Andrzej Kusiak, Olivier Fudym To cite this version: Jean-Luc Battaglia, Manal Saboul, Jérôme Pailhes, Abdelhak Saci, Andrzej Kusiak, et al.. Carbon epoxy composites thermal conductivity at 77 K and 300 K. Journal of Applied Physics, American Institute of Physics, 2014, 115 (22), pp.223516-1 - 223516-4. 10.1063/1.4882300. hal-01063420 HAL Id: hal-01063420 https://hal.archives-ouvertes.fr/hal-01063420 Submitted on 12 Sep 2014 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Science Arts & Métiers (SAM) is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. This is an author-deposited version published in: http://sam.ensam.eu Handle ID: .http://hdl.handle.net/10985/8502 To cite this version : Jean-Luc BATTAGLIA, Manal SABOUL, Jérôme PAILHES, Abdelhak SACI, Andrzej KUSIAK, Olivier FUDYM - Carbon epoxy composites thermal conductivity at 80 K and 300 K - Journal of Applied Physics - Vol. 115, n°22, p.223516-1 - 223516-4 - 2014 Any correspondence concerning this service should be sent to the repository Administrator : [email protected] Carbon epoxy composites thermal conductivity at 80 K and 300 K J.-L.
    [Show full text]
  • Measurements of the Thermal Conductivity and Electrical Resistivity of Platinum from 373 to 1373° K
    NATIONAL BUREAU OF STANDARDS REPORT 9387 MEASUREMENTS OF THE THERMAL CONDUCTIVITY AND ELECTRICAL RESISTIVITY OF PLATINUM FROM 373 TO 1373° K by D. R. Flynn Environmental Engineering Section Building Research Division Institute for Applied Technology National Bureau of Standards and M. E. O' Hagan School of Engineering and Applied Science The George Washington University DO NOT REFERENCE THIS DOCUMENT U. S. DEPARTMENT OF COMMERCE NATIONAL BUREAU OF STANDARDS — THE NATIONAL BUREAU OF STANDARDS The National Bureau of Standards 1 provides measurement and technical information services essential to the efficiency and effectiveness of the work of the Nation’s scientists and engineers. The Bureau serves also as a focal point in the Federal Government for assuring maximum application of the physical and engineering sciences to the advancement of technology in industry and commerce. To accomplish this mission, the Bureau is organized into three institutes covering broad program areas of research and services: THE INSTITUTE FOR BASIC STANDARDS . provides the central basis within the United States for a complete and consistent system of physical measurements, coordinates that system with the measurement systems of other nations, and furnishes essential services leading to accurate and uniform physical measurements throughout the Nation’s scientific community, industry, and commerce. This Institute comprises a series of divisions, each serving a classical subject matter area: —Applied Mathematics—Electricity—Metrology—Mechanics—Heat—Atomic Physics—Physical 2 - 2 Chemistry—Radiation Physics—Laboratory Astrophysics —Radio Standards Laboratory , which includes Radio Standards Physics and Radio Standards Engineering—Office of Standard Refer- ence Data. THE INSTITUTE FOR MATERIALS RESEARCH . conducts materials research and provides associated materials services including mainly reference materials and data on the properties of ma- terials.
    [Show full text]
  • Numerical Simulation of Heat Transfer Flow Subject to MHD of Williamson Nanofluid with Thermal Radiation
    S S symmetry Article Numerical Simulation of Heat Transfer Flow Subject to MHD of Williamson Nanofluid with Thermal Radiation Muhammad Amer Qureshi PYP-Mathematics, College of General Studies, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia; [email protected] Abstract: In this paper, heat transfer and entropy of steady Williamson nanofluid flow based on the fundamental symmetry is studied. The fluid is positioned over a stretched flat surface moving non- uniformly. Nanofluid is analyzed for its flow and thermal transport properties by consigning it to a convectively heated slippery surface. Thermal conductivity is assumed to be varied with temperature impacted by thermal radiation along with axisymmetric magnetohydrodynamics (MHD). Boundary layer approximations lead to partial differential equations, which are transformed into ordinary differential equations in light of a single phase model accounting for Cu-water and TiO2-water nanofluids. The resulting ODEs are solved via a finite difference based Keller box scheme. Various formidable physical parameters affecting fluid movement, difference in temperature, system entropy, skin friction and Nusselt number around the boundary are presented graphically and numerically discussed. It has also been observed that the nanofluid based on Cu-water is identified as a superior thermal conductor rather than TiO2-water based nanofluid. Keywords: Williamson-nanofluid; variable thermal conductivity; thermal radiation; entropy genera- tion; MHD; nanoparticle shape factor 1. Introduction The study of nanofluid flow and heat transfer has gained importance in the current era Citation: Amer Qureshi, M. Numer- due to its significant importance in engineering applications. In many processes, nanofluids ical Simulation of Heat Transfer Flow Subject to MHD of Williamson Nanofluid are used as a coolant in several industrial refrigeration systems and used in the process of oil with Thermal Radiation.
    [Show full text]
  • Microdroplet Formation of Water and Nanofluids in Heat-Induced
    Microfluid Nanofluid DOI 10.1007/s10404-008-0323-3 RESEARCH PAPER Microdroplet formation of water and nanofluids in heat-induced microfluidic T-junction S. M. Sohel Murshed Æ Say Hwa Tan Æ Nam Trung Nguyen Æ Teck Neng Wong Æ Levent Yobas Received: 16 April 2008 / Accepted: 16 June 2008 Ó Springer-Verlag 2008 Abstract This paper reports experimental investigations 1 Introduction on the droplet formation and size manipulation of deion- ized water (DIW) and nanofluids in a microfluidic T- Because of the potential applications of droplet-based mi- junction at different temperatures. Investigations of the crofluidics in various important fields such as chemical or effect of microchannel depths on the droplet formation biochemical analysis, high throughput screening, and fab- process showed that the smaller the depth of the channel rication of microparticles, the formation and manipulation the larger the increase of droplet size with temperature. of microdroplets is receiving increased interest from Sample nanofluids were prepared by dispersing 0.1 volume researchers worldwide (Joanicot and Ajdari 2005; Song percentage of titanium dioxide (TiO2) nanoparticles of et al. 2006; Whitesides 2006; Christopher and Anna 2007). 15 nm and 10 nm 9 40 nm in DIW for their droplet for- Although droplet-based microfluidics is still in its early mation experiments. The heater temperature also affects development stage (Whitesides 2006), applications such as the droplet formation process. Present results demonstrate reaction platforms for protein crystallization (Zheng et al. that nanofluids exhibit different characteristics in droplet 2003), cell encapsulation (He et al. 2005), polymerase formation with the temperature. Addition of spherical- chain reaction (Guttenberg et al.
    [Show full text]
  • The Viscosity and Thermal Conductivity Coefficients of Dilute Nitrogen and Oxygen
    jras : .<; : .:' '.: » l\l 1 ^rf' ' » * ^ 1 350 The Viscosity and Thermal Conductivity Coefficients of Dilute Nitrogen and Oxygen G. E. CHI LDS AND H. J. M. HANLEY F *** ° Cf »* U.S. DEPARTMENT OF COMMERCE ,&': Z (A National Bureau of Standards \ n ' *"*C A U O? — THE NATIONAL BUREAU OF STANDARDS The National Bureau of Standards 1 provides measurement and technical information services essential to the efficiency and effectiveness of the work of the Nation's scientists and engineers. The Bureau serves also as a focal point in the Federal Government for assuring maximum application of the physical and engineering sciences to the advancement of technology in industry and commerce. To accomplish this mission, the Bureau is organized into three institutes covering broad program areas of research and services: THE INSTITUTE FOR BASIC STANDARDS . provides the central basis within the United States for a complete and consistent system of physical measurements, coordinates that system with the measurement systems of other nations, and furnishes essential services leading to accurate and uniform physical measurements throughout the Nation's scientific community, industry, and commerce. This Institute comprises a series of divisions, each serving a classical subject matter area: —Applied Mathematics—Electricity—Metrology—Mechanics —Heat—Atomic Physics—Physical Chemistry—Radiation Physics—Laboratory Astrophysics 2—Radio Standards Laboratory, 2 which includes Radio Standards Physics and Radio Standards Engineering—Office of Standard Refer- ence Data. THE INSTITUTE FOR MATERIALS RESEARCH . conducts materials research and provides associated materials services including mainly reference materials and data on the properties of ma- terials. Beyond its direct interest to the Nation's scientists and engineers, this Institute yields services which are essential to the advancement of technology in industry and commerce.
    [Show full text]
  • Fast Temperature Changes for Polymerase Chain Reaction (PCR) on a Lab-On-A-Chip (Loac)
    BSc Report Fast temperature changes for polymerase chain reaction (PCR) on a lab-on-a-chip (LoaC) L.M.J. Nijsten FACULTY OF SCIENCE AND TECHNOLOGY Mesoscale Chemical Systems Examination Committee: Prof. dr. ir. H.J.M. ter Brake Energy, Materials & Systems Prof. dr. J.G.E. Gardeniers Mesoscale Chemical Systems Dr. ir. R.M. Tiggelaar Mesoscale Chemical Systems B. B. Bruijns MSc Mesoscale Chemical Systems Enschede, January 2013 1 L.M.J. Nijsten BSc Report University of Twente Mesoscale Chemical Systems January 2013 Table of Contents Summary ................................................................................................................................................. 4 1 Introduction ..................................................................................................................................... 5 2 Literature research .......................................................................................................................... 6 2.1 Polymerase Chain Reaction ..................................................................................................... 6 2.1.1 General ............................................................................................................................ 6 2.1.2 PCR methods ................................................................................................................... 7 2.1.3 PCR speed ........................................................................................................................ 7 2.2 PCR in microfluidic
    [Show full text]
  • Influence of Nanoparticle Volume Fraction, Particle Size and Temperature on Thermal Conductivity and Viscosity of Nanofluids- a Review
    International Journal of Automotive and Mechanical Engineering (IJAME) ISSN: 2229-8649 (Print); ISSN: 2180-1606 (Online); Volume 8, pp. 1316-1338, July-December 2013 ©Universiti Malaysia Pahang DOI: http://dx.doi.org/10.15282/ijame.8.2013.20.0108 INFLUENCE OF NANOPARTICLE VOLUME FRACTION, PARTICLE SIZE AND TEMPERATURE ON THERMAL CONDUCTIVITY AND VISCOSITY OF NANOFLUIDS- A REVIEW B. Ravisankar1 and V. Tara Chand2 1,2Faculty of Mechanical Engineering, R. V. R & J. C. College of Engineering, Guntur -522019, Andhra Pradesh, India; Phone: +91 9581062919. E-mail: [email protected] ABSTRACT In the present paper a critical literature review of nanofluid thermal conductivity and viscosity is performed. Experimental studies are discussed in terms of the effects of some parameters such as particle volume fraction, particle size, and temperature on thermal conductivity and viscosity of nanofluids. Theoretical models are explained, model predictions are compared with experimental data and discrepancies are indicated. Keywords: Nanofluid; particle size; temperature; thermal conductivity; viscosity; volume fraction. INTRODUCTION The fluids dispersed with nanoparticles known as nanofluids are promising for heat transfer enhancement due to their high thermal conductivity. Presently, there are discrepancies in the nanofluid thermal conductivity data in the literature and enhancement mechanisms have not been fully understood yet (Srinivasa Rao, Sharma, Chary, Bakar, Rahman, Kadirgama, & Noor, 2011). However, the viscosity of nanofluid is critical because the pumping power requirements and convective heat transfer coefficients of fluids depend strongly on the Reynolds and Prandtl numbers, which, in turn, are highly influenced by viscosity. Thus, accurate determination of the thermal conductivity and viscosity of nanofluids is very important in thermal applications.
    [Show full text]