DOCSLIB.ORG

Thermal Diffusivity and Thermal Conductivity of (Th,U)O2 Fuels

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Thermal Diffusivity and Thermal Conductivity of (Th,U)O2 Fuels THERMAL DIFFUSIVITY AND THERMAL CONDUCTIVITY OF (Th, U)O> FUELS by A. K. Sengupta, T. Jarvis, M. R. Nair, R. Ramachandran, S. Mujumdar and D. S. C. Purushotham Radiometallurgy Division 2000 32/ 05 PLEASE BE AWARE THAT ALL OF THE MISSING PAGES IN THIS DOCUMENT WERE ORIGINALLY BLANK BARC/2OOO/E/O15 -, GOVERNMENT OF INDIA < ATOMIC ENERGY COMMISSION THERMAL DIFFUSIVITY AND THERMAL CONDUCTIVITY OF (Th, U)O2 FUELS by A. K. Sengupta, TJarvis, M.R. Nair, R. Ramachandran, S. Majumdar and D.S.C. Purushotham Radiometallurgy Division BHABHA ATOMIC RESEARCH CENTRE MUMBAI, INDIA 2000 BARC/2000/E/015 BIBLIOGRAPHIC DESCRIPTION SHEET FOR TECHNICAL REPORT (as per IS : 9400 - 1980) 01 Security classification: Unclassified 02 Distribution : External 03 Report status: New 04 Series : BARC External 05 Report type: Technical Report 06 Report No. : BARC/2000/E/015 07 Part No. or Volume No. : 08 Contract No. : 10 Title and subtitle : Thermal diffusivity and thermal conductivity of (Th,U)O2 fuels 11 Collation : 25 p., 4 figs., 10 tabs. 13 Project No. : 20 Personal autnorts) : A. K. Sengupta; T. Jarvis; M.R. Nair; R. Ramachandran; S. Majumdar; D.S.C. Purushotham 21 Affiliation of authors): 1) Radiometallurgy Division, Bhabha Atomic Research Centre, Mumbai 22 Corporate authors): Bhabha Atomic Research Centre, Mumbai - 400 085 23 Originating unit: Radiometallurgy Division, BARC, Mumbai 24 Sponsors) Name: Department of Atomic Energy Type: Government Contd... (ii) -i- BARC/2000/E/015 30 Date of submission: April 2000 31 Publication/Issue date: May 2000 40 Publisher/Distributor: Head, Library and Information Services Division, Bhabha Atomic Research Centre, Mumbai 42 Form of distribution : Hard copy 50 Language of text: English 51 Language of summary: English 52 No. of references: lOrefs. 53 Gives data on : Abstract: India has vast reserves of thorium (> 460, 000 tons) and sustained work on all aspects of thorium utilization has been initiated. In this context work on fabrication of sintered thoria and mixed (Th,U)O2 pellets and evaluation of their thermophysical properties have been taken up in Radiometallurgy Division. Thermal conductivity, being the most important thermal properties, has been calculated using the experimentally measured thermal diffusivity, density and literature values of specific heats for ThO2 and thoria containing 2,4,6,10 and 20% UO2 Thermal diffusivity was measured experimentally by the laser flash method from 600 to 1600°C in vacuum.It was observed that thermal conductivity of ThO2and mixed (Th,U)O2 decrease with increase in temperature. It was also observed that the conductivity decreases with increase in UO2 content, the decrease being more at lower temperature than that at higher temperatures. Emperical relations correlating thermal conductivity to temperatures have been generated by the least square fit method and reported. 70 Keywords/Descriptors : THORIUM OXIDES; URANIUM OXIDES; MIXED OXIDE FUELS; FUEL PELLETS; THERMAL CONDUCTIVITY; THERMAL DIFFUSIVITY; SINTERING; EXPERIMENTAL DATA; TEMPERATURE DEPENDENCE; VERY HIGH PRESSURE; DENSITY 71 IMS Subject Category: S36 99 Supplementary elements: -n- ABSTRACT India has vast reserves of thorium (> 460, 000 tons) and sustained work on all aspects of thorium utilization has been initiated. In this context work on fabrication of sintered Thoria and mixed (Th,U)O2 pellets and evaluation of their thermophysical properties have been taken up in Radiometallurgy Division. Thermal conductivity, being the most important thermal properties, has been calculated using the experimentally measured thermal diffusivity, density and literature values of specific heats for ThO2 and thoria containing 2, 4, 6, 10 and 20% UO2. Thermal diffusivity was measured experimentally by the laser flash method from 600 to 1600°C in vacuum. It was observed that thermal conductivity of TI1O2 and mixed (Th,U)O2 decrease with increase in temperature. It was also observed that the conductivity decreases with increase in UO2 content, the decrease being more at lower temperature than that at higher temperatures. Empericai relations correlating thermal conductivity to temperatures have been generated by the least square fit method and reported. Thermal diffusivity and thermal conductivity of (Th,U)O2 fuels A.K. Sengupta, T. Jarvis, M.R. Nair, R. Ramachandran, S. Majumdar and O.S.C. Purushotham Radiometallurgy Division Bhabha Atomic Research Centre Trombay, Mumbai - 400085, INDIA. 1. Introduction : India has reached a major milestone in her ambitious thorium resource utilisation programmes by using Zircaloy clad ThC>2 bundles in the initial core of all new PHWRs for flux flattening. Apart from this, several tons of stainless steel clad ThC>2 pins have been fabricated for use as blanket material for fast breeder test reactor(FBTR) at Kalpakkam. Attempts are also being made to develop Thoria based fuels for PHWR. An Advance Heavy Water Reactor(AHWR), is being designed specifically for utilization of Thorium and generation of electricity. The behaviour of nuclear fuels during irradiation is dependent on the physico chemical properties of the fuel and their variation with temperature and burn up. For example, the fuel temperature is determined, amongst others, by the thermal conductivity of the fuel material. Other properties of importance are the coefficient of thermal expansion, specific heat, melting point etc. In the present investigation thermal conductivity of (Th,U)O2 solid solutions with UO2 content varying from 2 to 20w% have been calculated from the experimentally measured thermal diffusivity by laser flash method, literature values of specific heats of the solid solutions of ThO2 and UO2 and density. 2. Experimental: 2.1 Sample Preparation : ThO2 is a highly stable stoichiometric compound with very high melting point (3573K). Hence to obtain high density pellet at lower sintering temperature, it is necessary to dope thoria powder with about 500 ppm MgO. For better homogeneity, this doping was done in the solution stage before precipitation of oxalate. The characteristics of ihoria and urania powders used are given in Table 1. ThC>2 powder has a platelet morphology and hence it was milled for 4 hrs. The premilled ThC>2 powder was comilled with UO2 powder in a planetary ball mill for 2 hrs. Progressive milling technique was used for obtaining good homogeneity. The milled powders were double pre-compacted at 105 MPa and 150Mpa before granulation. Double precompaction was necessary for obtaining defect free green pellets which were produced by compacting the granules at 300 MPa in a double acting hydraulic press using a 12 mm diameter die. Sintering of the green compacts was carried out in a Molybdenum resistance batch furnace at 1923 K for 4 hrs. in Nitrogen + 8% Hydrogen atmosphere. Addition of UO2 to ThC>2 brings down the sintered density progressively. Average Green and Sintered density values as well as chemical analysis results for Uranium and Thorium contents in the sintered peilets are given in Tables 2 and 3. The details of the fabrication procedures along with the flow sheet are given in Reference [1J. The sintered pellet samples of diameter 10 mm and average height of about 15 mm for all the compositions were sliced using a low speed cut-off wheel to a thickness ranging from 2 to 2.5 mm for measurement of thermal diffusivity. The density of these sliced samples was calculated from the volume and mass of the sample. These samples were then coated on both the circular sides with a thin layer of graphite, using graphite spray(emulsion) and then were dried. Graphite spray ensures complete and uniform absorption of the laser energy by the sample and on the measuring side of the sample it maintains a black body condition. 2.2 Measurement Procedure: Thermal diffusivity was measured by the transient Laser flash method where a ruby laser with a pulse (square) energy of 6J was used as heating source. The disc-shaped specimens were held under adiabatic condition in a tungsten-mesh high temperature(upto 2000°C), high vacuum (10"6 Torr) furnace. The details of the experimental set up has been given in Ref. 2. The specimen was positioned along the optical axis of the ruby laser. The measurement procedure consisted of irradiating one surface of the sample by the pulsed laser and measuring/recording the rise in temperature (AT) on the other surface of the sample by an In-Sb I.R. detector. The temperature rise vs. time data was stored in the transient memory module for further calculations; using an on-line computer. The time taken for the rear surface of the sample to reach 20, 30, 40, 50, 60, 70 and 80% of the maximum temperature rise was recorded. Subsequently thermal diffusivity was calculated following the radiation heat loss correction procedures proposed by Clerk and Taylor [3]. Measurements were carried out in the temperature range 600°C to 1600°C in vacuum and at each temperature, the sample was soaked for about 5 minutes before laser irradiation was made. Few measurements were also performed during cooling cycle of the sample in order to ensure that the characteristics of the sample has not changed due to heating. Before carrying out measurements on actual samples, a standardization run was taken using Graphite standard(NBS SRM 8425). The data obtained are given in Table 4. It is observed that the experimental data is within ±2% of the recommended value of NBS.USA. 3. Results and Discussion : Experimental data on thermal diffusivity of thoria containing 2-20% UO2 are given in Table 5-10. Thermal conductivity of these materials were calculated from the literature value of specific heat(Cp), measured density(p) and the experimentally measured thermal diffusivity(a) using the following relation : k = a x p x Cp The specific heat data of the mixed (Th.U) oxides which form complete solid solution in the whole range of composition were calculated by adding the weighted fraction of the specific heats of UO2 and ThO2 for each composition.
Load more

Recommended publications
  • Thermal Conductivity of Selected Materials, Part 2
    . A11105 14bD4fl & TECH R,c NSfflDS-NBS 1 THT f /NSRDS-NBS * 46040 16 ' :2:196e G' 1 NBS~ piir-^ 19 . : . NBS PUBLICATIONS UNITED STATES DEPARTMENT OF COMMERCE Alexander B. Trowbridge, Secretary NATIONAL BUREAU OF STANDARDS • A. V. Astin, Director Thermal Conductivity of Selected Materials Part 2 C. Y. Ho,* R. W. Powell,*fC and P. E. Liley' *This report was prepared under contract at the Thermophysical Properties Research Center Purdue University, 2595 Yeager Road West Lafayette, Indiana 47906 NSRDS-NBS 16 National Standard Reference Data Series- National Bureau of Standards—16 (Category 5—Thermodynamic and Transport Properties) Issued February 1968 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 - Price $2 National Bureau of Standards SEP 4 151382 QC IOO ,U573 ® n • ! (p doty X Foreword The National Standard Reference Data System is a government-wide effort to give to the technical community of the United States optimum access to the quantitative data of physical science, critically evaluated and compiled for convenience. This program was established in 1963 by the President’s Office of Science and Technology, acting upon the recommendation of the Federal Council for Science and Technology. The National Bureau of Standards has been assigned responsibility for administering the effort. The general objective of the System is to coordinate and integrate existing data evaluation and compilation activities into a systematic, comprehensive program, supplementing and expanding technical coverage when necessary, establishing and maintaining standards for the output of the participating groups, and providing mechanisms for the dissemination of the output as required.
    [Show full text]
  • 3.37 (Class 4) Question: Thermal Diffusivity? • Thermal Diffusivity
    3.37 (Class 4) Question: thermal diffusivity? • Thermal Diffusivity (alpha) = Thermal Conductivity (k) / (density * heat capacity) • Combined, or derived parameter • From Fourier’s 1st law and 2nd law (diffusion equation) • deltaH = Cp*deltaT Question: Cold welding of semiconductors, is it gold-to-gold? Typically yes, gold pad Discussion about World Trade Center and Pentagon: • Why collapse? Structural members, lose part of the group, place more stress on the others, heat from the fire softens the steel, unzipping, once they let go then they bring down the other floors by impact loading from floors above • Why no tipping? Not really any force that would create tipping. Building has a large inertia. • Defense against terrorist attacks like this? o Dealing with people who are willing to die for what they believe o Have to be willing to pay the same price, have just as strongly held beliefs as this person. o Goes back many years: Why British not able to defeat the colonials? Same about Vietnam. Afghanistan like Vietnam to Soviets. Fighting for homeland. • People have a harder time dealing with man-made disasters than natural disasters. Review: • Contamination, rough surfaces and interfacial voids limit the strength of many joints • Liquids are often used to overcome surface roughness (adhesive bonding, soldering, brazing, fusion welding) • Interfacial shear is required for mechanically produced joints • Langmuir is 10^-8 atm*sec • pressure*time product for one monolayer of atoms to strike the surface • (also need to account for sticking factor, probability that stays when hits, for oxygen and metal this will be quite high, say 0.8) Contact are under normal loading never exceeds 1/3 apparent area Story: In 1980 working with test lab (guy inherited business from father, had a correspondence degree).
    [Show full text]
  • Effect of Testing Conditions on the Diffusivity Measurements of Nuclear Fuels Via the Flash Method C
    Effect of testing conditions on the diffusivity measurements of nuclear fuels via the flash method C. Duguay, M. Soulon, L. Sibaud To cite this version: C. Duguay, M. Soulon, L. Sibaud. Effect of testing conditions on the diffusivity measurements of nuclear fuels via the flash method. ECerS2017 - 15th Conference and Exhibition of the European Ceramic society, Jul 2017, Budapest, Hungary. ECerS2017 - 15th Conference and Exhibition of the European Ceramic society, 2017. hal-02417740 HAL Id: hal-02417740 https://hal.archives-ouvertes.fr/hal-02417740 Submitted on 18 Dec 2019 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. Christelle DUGUAY, Mathias SOULON and Laurène SIBAUD Commissariat à l’Énergie Atomique et aux Énergies Alternatives (CEA), DEN/DEC Centre de Cadarache , 13108 Saint-Paul-Lez-Durance Cedex, France, E-mail : [email protected] Context and objectives Thermal conductivity of the nuclear fuel : λλλ ρρρ A key parameter to understand the performance of the fuel under irradiation (T) = a(T).C p(T). (T) Highly dependent on microstructure,
    [Show full text]
  • Thermal Diffusivity and Volumetric Specific Heat Measurements Using Heat Flow Meter Instruments for Thermal Conductivity 29 / Thermal Expansion 17 Conference *
    Title: Thermal Diffusivity and Volumetric Specific Heat Measurements Using Heat Flow Meter Instruments for Thermal Conductivity 29 / Thermal Expansion 17 Conference * Authors: Akhan Tleoubaev Andrzej Brzezinski * not published in the Proceedings because of late submission ABSTRACT Heat Flow Meter Method (ASTM C518, ISO 8301, EN 1946-3, etc.) instruments are the most widely used steady-state type of devices for thermal conductivity measurements. In computerized systems the heat flow meters’ (transducers’) signals can be recorded versus time. The recorded signals can give additional information about other important thermal properties of the samples – volumetric specific heat and thermal diffusivity. Volumetric specific heat can be calculated simply from amount of the heat flow per square area absorbed by sample after switching instrument’s plates’ temperature set points from one (after reaching thermal equilibrium condition) to another (until reaching new thermal equilibrium condition) . For thermal diffusivity calculations two unsteady state thermal problems solutions should be used: 1) with boundary conditions of 1st kind (so-called ideal thermal contact, i.e. when thermal contact resistance is negligible) - for samples of low thermal conductivity, and 2) with boundary conditions of 3rd kind (in presence of thermal contact resistance) - for samples of moderate thermal conductivity. After reaching so-called “regular regime” thermal diffusivity of the specimen can be calculated using slopes of the graphs of logarithms of the heat-flow meters’ signals versus time (slopes of their linear part) during the process of the system’s exponential relaxation toward the final thermal equilibrium. Experimental checks using several materials - Expanded Polystyrene, 1450b and 1450c NIST Standard Reference Materials, Pyrex 7740, Vespel SP1, Perspex, Pyroceram 9606 were done.
    [Show full text]
  • Elastic and Thermal Properties of Free-Standing Molybdenum Disulfide Membranes Measured Using Ultrafast Transient Grating Spectr
    Elastic and thermal properties of free-standing molybdenum disulfide membranes measured using ultrafast transient grating spectroscopy Taeyong Kim, , Ding Ding, , Jong-Hyuk Yim, , Young-Dahl Jho, and , and Austin J. Minnich Citation: APL Materials 5, 086105 (2017); doi: 10.1063/1.4999225 View online: http://dx.doi.org/10.1063/1.4999225 View Table of Contents: http://aip.scitation.org/toc/apm/5/8 Published by the American Institute of Physics APL MATERIALS 5, 086105 (2017) Elastic and thermal properties of free-standing molybdenum disulfide membranes measured using ultrafast transient grating spectroscopy Taeyong Kim,1,a Ding Ding,2,a Jong-Hyuk Yim,3 Young-Dahl Jho,3,b and Austin J. Minnich1,c 1Division of Engineering and Applied Science, California Institute of Technology, Pasadena, California 91125, USA 2Singapore Institute of Manufacturing Technology, 2 Fusionopolis Way, Singapore 138634, Singapore 3School of Electrical Engineering and Computer Science, Gwangju Institute of Science and Technology, Gwangju 61005, South Korea (Received 25 April 2017; accepted 2 August 2017; published online 21 August 2017) Molybdenum disulfide (MoS2), a member of transition-metal dichalcogenide family, is of intense interest due to its unique electronic and thermoelectric properties. How- ever, reports of its in-plane thermal conductivity vary due to the difficulty of in-plane thermal conductivity measurements on thin films, and an experimental measurement of the in-plane sound velocity has not been reported. Here, we use time-resolved transient grating spectroscopy to simultaneously measure the in-plane elastic and thermal prop- erties of free-standing MoS2 membranes at room temperature. We obtain a longitudinal acoustic phonon velocity of 7000 ± 40 m s 1 and an in-plane thermal conductivity of 74 ± 21 W m 1K 1.
    [Show full text]
  • Investigation of the Optical, Thermal, and Mechanical Properties of a Bulk Polymer Using the Surface Thermal Lensing Technique Bushra Hussain
    Eastern Michigan University DigitalCommons@EMU Master's Theses, and Doctoral Dissertations, and Master's Theses and Doctoral Dissertations Graduate Capstone Projects 2005 Investigation of the optical, thermal, and mechanical properties of a bulk polymer using the surface thermal lensing technique Bushra Hussain Follow this and additional works at: http://commons.emich.edu/theses Part of the Physics Commons Recommended Citation Hussain, Bushra, "Investigation of the optical, thermal, and mechanical properties of a bulk polymer using the surface thermal lensing technique" (2005). Master's Theses and Doctoral Dissertations. 114. http://commons.emich.edu/theses/114 This Open Access Thesis is brought to you for free and open access by the Master's Theses, and Doctoral Dissertations, and Graduate Capstone Projects at DigitalCommons@EMU. It has been accepted for inclusion in Master's Theses and Doctoral Dissertations by an authorized administrator of DigitalCommons@EMU. For more information, please contact [email protected]. INVESTIGATION OF THE OPTICAL, THERMAL, AND MECHANICAL PROPERTIES OF A BULK POLYMER USING THE SURFACE THERMAL LENSING TECHNIQUE By Bushra Hussain Thesis Submitted to the Department of Physics and Astronomy Eastern Michigan University In partial fulfillment of the requirements For the degree of MASTER OF SCIENCE in Physics August 23, 2005 Ypsilanti, Michigan DEDICATION To my Brother, Syed Intesar Hussain ii ACKNOWLEDGEMENTS I feel great pleasure to express my sincere gratitude to my thesis advisor Professor Marshall Thomsen for initiating this research topic and for his constructive criticism, encouragement, guidance, support, and patience throughout the length of this investigation. I would also like to thank Professor Donald Snyder of the Chemistry Department, who collaborated with Professor Marshall Thomsen, for his support and guidance whenever I needed it.
    [Show full text]
  • Analytical Modeling of Temperature Distribution, Peak
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector Available online at www.sciencedirect.com ScienceDirect Procedia Materials Science 6 ( 2014 ) 821 – 834 3rd International Conference on Materials Processing and Characterisation (ICMPC 2014) Analytical Modeling of Temperature Distribution, Peak Temperature, Cooling Rate and Thermal Cycles in a Solid Work Piece Welded By Laser Welding Process K.Suresh Kumara,b* a Research Scholar,University of Madras, Chennai,Tamil Nadu,600005,India bP.T.LeeChengalvaraya Naicker College of Engineering and Technology,Kanchipuram,Tamil Nadu,631502,India Abstract Generalized theoretical prediction of temperature distribution, peak temperature, cooling rate and thermal cycles in a solid work piece welded by laser welding process, where no melting is occurs, i.e., from the boundary of fusion zone to the end of heat affected zone. With the moving point or line heat source may be considered for the analysis that indicates the temperature gradient ahead of the heat source is much higher than that behind, increasing welding velocity elongates the isotherms surrounding the heat source, higher thermal conductivity of materials make the isotherm more circular, reducing the temperature gradient in front of the heat source. The peak temperature experienced throughout the workpiece, determine the size of the heat affected zone (HAZ). The peak temperature at a given point is experienced by the point shortly after it is passed by the heat source. The size of the HAZ increases with the net energy input. The cooling rates experienced by a material, determines the grain structure and phases that are formed.
    [Show full text]
  • A Method for Indirect Measurements of Thermal Properties of Foods
    SIK-rapport 2002, No. 703 A Method for Indirect Measurements of Thermal Properties of Foods Eva Olsson, Hans Janestad, Lilia Ahrné SIK-rapport 2002, No. 703 A Method for Indirect Measurements of Thermal Properties of Foods Eva Olsson, Hans Janestad, Lilia Ahrné Göteborg, 2002 ISBN 91-7290-223-X ABSTRACT A method has been developed for the simultaneous estimation of thermal diffusivity, thermal conductivity, volumetric heat capacity and the heat transfer coefficient for foods heated/cooled by convection. The method uses experimental time-temperature data of the food and the medium, which are used in a parameter estimation procedure based on the conduction heat transfer equation in one dimension for an infinite cylinder. To increase the accuracy in the results the estimations are performed in a number of sub-steps under varied model conditions, for example is an inner fictive cylinder used. The suggested method estimated the thermal diffusivity, the heat conduction and the volumetric heat capacity with a maximal relative error in the interval 6-9%. This study shows the well known difficulty of separating the thermal conductivity and the volumetric heat capacity in the expression for the thermal diffusivity, caused among other things by the uncertainty in the estimation of the heat transfer coefficient. TABLE OF CONTENTS INTRODUCTION.............................................................................................................................. 2 MATERIALS AND METHODS..........................................................................................................
    [Show full text]
  • Measurements of Thermophysical Property of Thin Films by Light Pulse Heating Thermoreflectance Methods T
    MEASUREMENTS OF THERMOPHYSICAL PROPERTY OF THIN FILMS BY LIGHT PULSE HEATING THERMOREFLECTANCE METHODS T. Baba, K. Ishikawa, T. Yagi, N. Taketoshi To cite this version: T. Baba, K. Ishikawa, T. Yagi, N. Taketoshi. MEASUREMENTS OF THERMOPHYSICAL PROP- ERTY OF THIN FILMS BY LIGHT PULSE HEATING THERMOREFLECTANCE METHODS. THERMINIC 2006, Sep 2006, Nice, France. pp.151-156. hal-00171371 HAL Id: hal-00171371 https://hal.archives-ouvertes.fr/hal-00171371 Submitted on 12 Sep 2007 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. Nice, Côte d’Azur, France, 27-29 September 2006 MEASUREMENTS OF THERMOPHYSICAL PROPERTY OF THIN FILMS BY LIGHT PULSE HEATING THERMOREFLECTANCE METHODS Tetsuya Baba, Kazuko Ishikawa, Takashi Yagi, Naoyuki Taketoshi National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology AIST Tsukuba Central 3, Umezono 1-1-1, Tsukuba, Ibaraki, 305-8563, Japan Kimiaki Tamano, Tetsuro Ohtsuka, Hiroshi Watanabe, Yuzo Shigesato Department of Chemistry School of Science & Engineering Aoyama Gakuin University, Fuchinobe, Sagamihara, Kanagawa, 229-8558 Japan ABSTRACT [4]. Thermal diffusivity of submicrometer thin films per- pendicular to the surface was calculated from the cooling Thermoreflectance methods by picosecond light pulse rate of the surface temperature and the penetration depth heating and by nanosecond light pulse heating have been of the heating light.
    [Show full text]
  • Measurement of Thermal Conductivity Anddiffusivity in Situ
    FI9900089 POSIVA 99-01 Measurement of thermal conductivity and diffusivity in situ: Literature survey and theoretical modelling of measurements Mmo Kukkonen Ilkka Suppala Geological Survey of Finland 30-17 January 1999 POSIVA OY Mikonkatu 15 A. FIN-OO1OO HELSINKI. FINLAND Phone (09) 2280 30 (nat). ( + 358-9-) 2280 30 (int.) Fax (09) 2280 3719 (nat.). ( + 358-9-) 2280 3719 (int.) ISBN 951-652-056-1 ISSN 1239-3096 The conclusions and viewpoints presented in the report are those of author(s) and do not necessarily coincide with those of Posiva. ti - POSiva Report Raportintunnus- Report code POSIVA 99-01 Mikonkatu 15 A, FIN-00100 HELSINKI, FINLAND Julkaisuaika - Date Puh. (09) 2280 30 - Int. Tel. +358 9 2280 30 January 1999 Tekija(t) - Author(s) Toimeksiantaja(t) - Commissioned by Ilmo Kukkonen Ilkka Suppala Posiva Oy Geological Survey of Finland Nimeke - Title MEASUREMENT OF THERMAL CONDUCTIVITY AND DIFFUSIVITY IN SITU: LITERATURE SURVEY AND THEORETICAL MODELLING OF MEASUREMENTS Tiivistelma - Abstract In situ measurements of thermal conductivity and diffusivity of bedrock were investigated with the aid of a literature survey and theoretical simulations of a measurement system. According to the surveyed literature, in situ methods can be divided into 'active' drill hole methods, and 'passive' indirect methods utilizing other drill hole measurements together with cutting samples and petrophysical relationships. The most common active drill hole method is a cylindrical heat producing probe whose temperature is registered as a function of time. The temperature response can be calculated and interpreted with the aid of analytical solutions of the cylindrical heat conduction equation, particularly the solution for an infinite perfectly conducting cylindrical probe in a homogeneous medium, and the solution for a line source of heat in a medium.
    [Show full text]
  • Polymer Processing Modeling and Simulation
    Tim Osswald Juan P. Hernández-Ortiz Polymer Processing Modeling and Simulation Sample Chapter 2: Processing Properties ISBNs 978-1-56990-398-8 HANSER 1-56990-398-0 Hanser Publishers, Munich • Hanser Publications, Cincinnati CHAPTER 2 PROCESSING PROPERTIES Didyou ever considerviscoelasticity? —Arthur Lodge 2.1THERMAL PROPERTIES The heat flowthrough amaterial can be definedbyFourier’s lawofheat conduction. Fourier’s lawcan be expressedas ∂T q = − k (2.1) x x ∂x where q x is theenergy transport perunitarea in the x direction, k x thethermal conductivity and ∂T/∂x thetemperaturegradient. At theonset of heating, thepolymerresponds solely as aheat sink, and theamount of energy per unit volume, Q ,stored in thematerialbefore reaching steady state conditions can be approximated by Q = ρCp ∆ T (2.2) where ρ is thedensity of thematerial, C p the specific heat, and ∆ T thechange in temperature. Thematerial properties found in eqns.(2.1) and(2.2) areoften written as onesingleproperty, 38 PROCESSING PROPERTIES Table2.1: ThermalPropertiesfor Selected Polymeric Materials Polymer Specific Specific Thermal Coeff. Thermal Max gravity heat conduc. therm. diffusivity temp. expan. kJ/kg/KW/m/K µ m/m/K(m 2 /s)10− 7 o C ABS1.04 1.47 0.3901.7 70 CA 1.28 1.50 0.15 100 1.04 60 EP 1.9 -0.23 70 -130 PA66 1.14 1.67 0.24 90 1.01 90 PA66-30% glass1.38 1.26 0.52 30 1.33 100 PC 1.15 1.26 0.2 65 1.47 125 PE-HD0.95 2.3 0.63 120 1.57 55 PE-LD 0.92 2.3 .33200 1.17 50 PET 1.37 1.05 0.24 90 -110 PF 1.4 1.3 0.35 22 1.92 185 PMMA 1.18 1.47 0.2 70 1.09 50 POM 1.42 1.47 0.2800.7 85
    [Show full text]
  • Characteristic Temperature Curves for Aluminum Alloys During Friction Stir Welding
    Hamilton et al Supp Sept 2010layout:Layout 1 8/12/10 10:49 AM Page 189 Characteristic Temperature Curves for Aluminum Alloys during Friction Stir Welding An empirically derived relationship between temperature and weld energy is used to predict maximum friction stir welding temperatures in aluminum alloys BY C. HAMILTON, S. DYMEK, AND A. SOMMERS Ulysse (Ref. 7) studied the impact of vary- ABSTRACT ing weld parameters on the temperature distribution in 7050-T7451 plate. Also, Review of published friction stir welding (FSW) data across numerous aluminum Khandkar et al. (Refs. 8, 9) introduced a alloys demonstrates that a characteristic relationship between the temperature ratio heat input model based on the torque of (the maximum welding temperature divided by the solidus temperature of the alloy) the FSW tool and successfully applied the and the energy per unit length of weld exists. When the temperature ratio is plotted as model to friction stir welded aluminum a function of the energy per unit length of weld, a linear relationship whose slope is de- 6061-T651 plate. pendent on the thermal diffusivity of the alloy is revealed. Utilizing these characteris- A commonality to each of these ap- tic curves, the maximum welding temperatures were estimated for Sc-modified Al-Zn- proaches, however, is the need to develop Mg-Cu alloy extrusions joined through FSW at 225, 250, 300, and 400 rev/min (all other a computer simulation to satisfactorily weld parameters held constant). The characteristic curves successfully predict the max- solve the heat transfer equation for the imum weld temperatures at the lower energy weld conditions, i.e., 225 and 250 rev/min, alloy and welding conditions of interest, but for the high-energy welds, 300 and 400 rev/min, the curves overpredict the maxi- and to calculate the thermal profile and mum weld temperatures.
    [Show full text]