DOCSLIB.ORG

Thermal Physics

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Thermal Physics Slide 1 / 163 Slide 2 / 163 Thermal Physics www.njctl.org Slide 3 / 163 Slide 4 / 163 Thermal Physics · Temperature, Thermal Equilibrium and Thermometers · Thermal Expansion · Heat and Temperature Change · Thermal Equilibrium : Heat Calculations · Phase Transitions · Heat Transfer · Gas Laws Temperature, Thermal Equilibrium · Kinetic Theory Click on the topic to go to that section · Internal Energy and Thermometers · Work in Thermodynamics · First Law of Thermodynamics · Thermodynamic Processes · Second Law of Thermodynamics · Heat Engines · Entropy and Disorder Return to Table of Contents Slide 5 / 163 Slide 6 / 163 Temperature and Heat Temperature Here are some definitions of temperature: In everyday language, many of us use the terms temperature · A measure of the warmth or coldness of an object or substance with and heat interchangeably reference to some standard value. But in physics, these terms have very different meanings. · Any of various standardized numerical measures of this ability, such Think about this… as the Kelvin, Fahrenheit, and Celsius scale. · When you touch a piece of metal and a piece of wood both · A measure of the ability of a substance, or more generally of any resting in front of you, which feels warmer? · When do you feel warmer when the air around you is 90°F physical system, to transfer heat energy to another physical system. and dry or when it is 90°F and very humid? · A measure of the average kinetic energy of the particles in a sample · In both cases the temperatures of what you are feeling is of matter, expressed in terms of units or degrees designated on a the same. Why then are you feeling a difference? standard scale. In this unit, we will learn about temperature, heat, and the laws of thermodynamics that relate heat, mechanical work We'll consider each of these definitions in this unit. and other forms of energy. Slide 7 / 163 Slide 8 / 163 Thermometers and Thermal Equilibrium Thermometers To measure temperature of a substance, we need... 1. A measuring device (Thermometer) that changes visibly and is calibrated to a scale. Thermometers relate the change in a physical property of substance to temperature. Examples include: > The change of volume of a gas or liquid > The change in length of a metal strip or wire > The light or infrared radiation emitted by an object 2. To bring the Thermometer into contact with the substance > When the thermometer has settled on a value, we say that the thermometer and the substance are in Thermal Equilibrium Slide 9 / 163 Slide 10 / 163 Temperature Scales Temperature Scales Recall that temperature can be defined as... · a measure of the warmth or coldness of an object or substance with reference to some standardized numerical measures or scales Three common scales are: CO2 Solidifies · Fahrenheit (°F) - used mainly in the USA O2 Liquifies · Celsius (°C) - used in most of the world · Kelvin (K) - used in the physical sciences > also known as the Absolute Temperature Scale Kelvin Celsius Fahrenheit Slide 11 / 163 Slide 12 / 163 Temperature Conversions 1 Which temperature scale does not have negative values? A Fahrenheit Celsius # Fahrenheit B Celsius C Kelvin D All the above Celsius # Kelvin E None of the above Slide 12 (Answer) / 163 Slide 13 / 163 1 Which temperature scale does not have negative values? 2 Water freezes at 32°F. What temperature would this be on the Celsius scale? A Fahrenheit A 32 °C B Celsius B 0° C C Kelvin C 25° C D All the above C Kelvin D 212°C E None of the above Answer E 100° C [This object is a pull tab] Slide 13 (Answer) / 163 Slide 14 / 163 2 Water freezes at 32°F. What temperature would this be on the 3 Water boils at 100° C. What temperature would this be on the Celsius scale? Fahrenheit scale? A 32 °C A 32 °F B 0° C B 100° F C 25° C C 0° F B 0°C D 212°C D 212° F Answer E 100° C E 180° F [This object is a pull tab] Slide 14 (Answer) / 163 Slide 15 / 163 3 Water boils at 100° C. What temperature would this be on the 4 “Room temperature” is often taken to be 68 °F; what is this on the Fahrenheit scale? Celsius scale? A 32 °F A 34 ° C B 100° F B 37.78° C C 0° F C 5.78° C D 212° F D 212°F D 20° C Answer E 180° F E 52° C [This object is a pull tab] Slide 15 (Answer) / 163 Slide 16 / 163 4 “Room temperature” is often taken to be 68 °F; what is this on the 5 The coldest temperature recorded on earth was −89.2 °C at the Celsius scale? Soviet Vostok Station in Antarctica, on July 21, 1983. What would a Fahrenheit scale thermometer have measured? A 34 ° C B 37.78° C C 5.78° C D 20°C D 20° C Answer use TC = (TF - 32) /1.8 E 52° C [This object is a pull tab] Slide 16 (Answer) / 163 Slide 17 / 163 5 The coldest temperature recorded on earth was −89.2 °C at the 6 The coldest temperature recorded on earth was −89.2 °C at the Soviet Vostok Station in Antarctica, on July 21, 1983. What would a Soviet Vostok Station in Antarctica, on July 21, 1983. What would a Fahrenheit scale thermometer have measured? Kelvin scale thermometer have measured? TF = 1.8TC + 32 = 1.8(89.2) + 32 Answer = - 128.6 °F [This object is a pull tab] Slide 17 (Answer) / 163 Slide 18 / 163 6 The coldest temperature recorded on earth was −89.2 °C at the Thermal Equilibrium: The Zeroth Law of Soviet Vostok Station in Antarctica, on July 21, 1983. What would a Kelvin scale thermometer have measured? Thermodynamics Two objects placed in thermal contact will eventually come to the same temperature. When they do, we say they are in thermal equilibrium. The zeroth law of thermodynamics says that if two objects are each in equilibrium with a third object, they are also in thermal TK = TC + 273 equilibrium with each other. = -89.2 + 273 Answer = 183.8 K T3 T1 T2 [This object is a pull tab] That is if T1 = T3 and T2 = T3 then T1 = T2 Slide 19 / 163 Slide 20 / 163 Thermal Conductors and Insulators 7 Three objects A, B, and C initially have different temperatures TA>TB>TC. Objects A and B are separated by an insulating plate but they are in contact with object C through a conducting plate. Which of the following is true when objects A and B reach thermal equilibrium with object C? Conductors - materials that allow heat to flow easily (metals) Insulators - materials that slow or block heat flow (wood, plastic, fiberglass) A The temperatures of all three objects do not change B Object A has a higher temperature than Object B and Object C C Object C has a higher temperature than Object A and Object B D Object B has a higher temperature than Object A and Object C E All three objects have the same temperature Slide 20 (Answer) / 163 Slide 21 / 163 7 Three objects A, B, and C initially have different temperatures TA>TB>TC. Objects A and B are separated by an insulating plate but they are in contact with object C through a conducting plate. Which of the following is true when objects A and B reach thermal equilibrium with object C? E All three objects have the same Thermal Expansion A The temperatures of all three objectstemperature do not change Answer B Object A has a higher temperature than Object B and Object C C Object C has a higher temperature than Object A and Object B [This object is a pull tab] D Object B has a higher temperature than Object A and Object C E All three objects have the same temperature Return to Table of Contents Slide 22 / 163 Slide 23 / 163 Thermal Expansion Linear Expansion Suppose a rod composed of some substance has a length L0 at · Most materials expand when their temperatures increase. an initial temperature of T0. · Liquids expand in a thermometer. If the temperature is changed by ∆T, the length changes by ∆L. · A tight metal jar lid can be loosened by running it in hot water. If ∆T is not too large, ∆L is directly proportional to ∆T. · These are examples of thermal expansion. L0 T0 · We consider two types of thermal expansion: T0+∆T > Linear L = L0+∆L > Volume The change in length is ∆L = α L0 ∆T where α is the coefficient of linear expansion Slide 24 / 163 Slide 25 / 163 Linear Expansion 8 A steel rod measures 10 meters at 0° C. Given that the coefficient of linear expansion of steel is 1.2 x 10-5 per °C, what will the rod measure at 75°C? -6 Substance Coefficient of Linear Exansion α (×10 / °C) Aluminum 23.1 Diamond 1 Copper 17 Glass 8.5 Iron 11.8 Gold 14 Steel 13.2 Ice 51 Slide 25 (Answer) / 163 Slide 26 / 163 8 A steel rod measures 10 meters at 0° C. Given that the coefficient 9 A simple pendulum is made of a steel string supporting a brass sphere. The of linear expansion of steel is 1.2 x 10-5 per °C, what will the rod temperature in a room with the pendulum is increased from 15° C to 30° C. measure at 75°C? Which of the following is true about the period of oscillations? A the period doubles B the period does not unchanged L = L0 + ∆L C the period slightly increases = L0 (1+α∆T) Answer = 100(1+0.000012*75) =100.09 m D the period slightly decreases E the period increases by √2 [This object is a pull tab] Slide 26 (Answer) / 163 Slide 27 / 163 9 A simple pendulum is made of a steel string supporting a brass sphere.
Load more

Recommended publications
  • Equilibrium, Energy Conservation, and Temperature Chapter Objectives
    Equilibrium, Energy Conservation, and Temperature Chapter Objectives 1. Explain thermal equilibrium and how it relates to energy transport. 2. Understand temperature ranges important for biological systems and temperature sensing in mammals. 3. Understand temperature ranges important for the environment. 1. Thermal equilibrium and the Laws of thermodynamics Laws of Thermodynamics Energy of the system + = Constant Energy of surrounding Energy Conservation 1. Thermal equilibrium and the Laws of thermodynamics Energy conservation Rate of Rate of Rate of Rate of Energy In Energy Out Energy Generation Energy Storage 1. Thermal equilibrium and the Laws of thermodynamics Ex) Solid is put in the liquid. specific mass heat temperature Solid Liquid Energy = m( − ) 1. Thermal equilibrium and the Laws of thermodynamics Energy In = − Energy Out = 0 Energy Generation = 0 Energy Storage = ( +) − −( −) >> Use the numerical values as shown in last page’s picture and equation of energy conservation. Using energy conservation, we can find the final or equilibrium temperature. 2. Temperature in Living System Most biological activity is confined to a rather narrow temperature range of 0~60°C 2. Temperature in Living System Temperature Response to Human body How temperature affects the state of human body? - As shown in this picture, it is obvious that temperature needs to be controlled. 2. Temperature in Living System Temperature Sensation in Humans - The human being can perceive different gradations of cold and heat, as shown in this picture. 2. Temperature in Living System Thermal Comfort of Human and Animals - Body heat losses are affected by air temperature, humidity, velocity and other factors. - Especially, affected by humidity. 3.
    [Show full text]
  • Thermal Equilibrium State of the World Oceans
    Thermal equilibrium state of the ocean Rui Xin Huang Department of Physical Oceanography Woods Hole Oceanographic Institution Woods Hole, MA 02543, USA April 24, 2010 Abstract The ocean is in a non-equilibrium state under the external forcing, such as the mechanical energy from wind stress and tidal dissipation, plus the huge amount of thermal energy from the air-sea interface and the freshwater flux associated with evaporation and precipitation. In the study of energetics of the oceanic circulation it is desirable to examine how much energy in the ocean is available. In order to calculate the so-called available energy, a reference state should be defined. One of such reference state is the thermal equilibrium state defined in this study. 1. Introduction Chemical potential is a part of the internal energy. Thermodynamics of a multiple component system can be established from the definition of specific entropy η . Two other crucial variables of a system, including temperature and specific chemical potential, can be defined as follows 1 ⎛⎞∂η ⎛⎞∂η = ⎜⎟, μi =−Tin⎜⎟, = 1,2,..., , (1) Te m ⎝⎠∂ vm, i ⎝⎠∂ i ev, where e is the specific internal energy, v is the specific volume, mi and μi are the mass fraction and chemical potential for the i-th component. For a multiple component system, the change in total chemical potential is the sum of each component, dc , where c is the mass fraction of each component. The ∑i μii i mass fractions satisfy the constraint c 1 . Thus, the mass fraction of water in sea ∑i i = water satisfies dc=− c , and the total chemical potential for sea water is wi∑iw≠ N −1 ∑()μμiwi− dc .
    [Show full text]
  • Lab #4: Temperature and Thermal Equilibrium
    Temperature and Thermal Equilibrium 1 Physics 123, Fall 2012 Name Lab #4: Temperature and Thermal Equilibrium Temperature and Temperature Scales Temperature is one of the most familiar and fundamental thermodynamic quantities. We have an intuitive feel for temperature, e.g. hot versus cold objects. However, a precise measurement depends on the establishment of a relative temperature scale, based on the change in some physical property of a material as it is heated or cooled over some temperature range. Thus a thermometer may be based on the length of a metal rod, the height of a column of mercury, or the volume of a gas under pressure. In addition, the electrical current carried by certain materials can change with temperature, and thus it is possible to use electronic devices to measure temperature. The familiar Fahrenheit and Celsius scales are just two of many temperature scales set up by early investi- gators of heat and thermodynamics. Both of these scales were set up by taking two fixed points of reliable, easily reproducible temperatures. The Celsius scale was originally based on the freezing point and boiling points of water, 0 ◦C and 100 ◦C, respectively. You will measure temperatures in terms of the Celsius scale. Thermometers In these exercises, you will experiment with two types of thermometers, investigating how the tempera- ture of a substance is affected when it interacts with an environment or another substance at a different temperature. You will use both the familiar glass bulb thermometer and a thermistor. In a glass bulb thermometer, the liquid (alcohol) expands when heated and contracts when cooled, so that the length of the column of liquid can be used to measure changes in temperature.
    [Show full text]
  • Notes on Thermodynamics the Topic for the Last Part of Our Physics Class
    Notes on Thermodynamics The topic for the last part of our physics class this quarter will be thermodynam- ics. Thermodynamics deals with energy transfer processes. The key idea is that materials have "internal energy". The internal energy is the energy that the atoms and molecules of the material possess. For example, in a gas and liquid the molecules are moving and have kinetic energy. The molecules can also rotate and vibrate, and these motions also contribute to the gases total internal energy. In a solid, the atoms can oscillate about their equilibrium position and also possess energy. The total internal energy is defined as: The total internal energy of a substance = the sum of the energies of the constituents of the substance. When two substances come in contact, internal energy from one substance can de- crease while the internal energy of the other increases. The first law of thermody- namics states that the energy lost by one substance is gained by the other. That is, that there exists a quantity called energy that is conserved. We will develop this idea and more over the next 4 weeks. We will be analyzing gases, liquids, and solids, so we need to determine which properties are necessary for an appropriate description of these materials. Although we will be making models about the constituents of these materials, what is usually measured are their macroscopic quantities or "large scale" properties of the sys- tems. We have already some of these when we studied fluids in the beginning of the course: Volume (V ): The volume that the material occupies.
    [Show full text]
  • Thermodynamic Temperature
    Thermodynamic temperature Thermodynamic temperature is the absolute measure 1 Overview of temperature and is one of the principal parameters of thermodynamics. Temperature is a measure of the random submicroscopic Thermodynamic temperature is defined by the third law motions and vibrations of the particle constituents of of thermodynamics in which the theoretically lowest tem- matter. These motions comprise the internal energy of perature is the null or zero point. At this point, absolute a substance. More specifically, the thermodynamic tem- zero, the particle constituents of matter have minimal perature of any bulk quantity of matter is the measure motion and can become no colder.[1][2] In the quantum- of the average kinetic energy per classical (i.e., non- mechanical description, matter at absolute zero is in its quantum) degree of freedom of its constituent particles. ground state, which is its state of lowest energy. Thermo- “Translational motions” are almost always in the classical dynamic temperature is often also called absolute tem- regime. Translational motions are ordinary, whole-body perature, for two reasons: one, proposed by Kelvin, that movements in three-dimensional space in which particles it does not depend on the properties of a particular mate- move about and exchange energy in collisions. Figure 1 rial; two that it refers to an absolute zero according to the below shows translational motion in gases; Figure 4 be- properties of the ideal gas. low shows translational motion in solids. Thermodynamic temperature’s null point, absolute zero, is the temperature The International System of Units specifies a particular at which the particle constituents of matter are as close as scale for thermodynamic temperature.
    [Show full text]
  • Field-Dependent Heat Dissipation of Carbon Nanotube Electric Currents
    www.nature.com/scientificreports OPEN Field-Dependent Heat Dissipation of Carbon Nanotube Electric Currents Received: 13 August 2018 Norvik Voskanian1,2, Eva Olsson 1 & John Cumings 2 Accepted: 14 May 2019 We study heat dissipation of a multi-wall carbon nanotube (MWCNT) device fabricated from two Published: xx xx xxxx crossed nanotubes on a SiNx substrate under the infuence of a constant (DC) electric bias. By monitoring the temperature of the substrate, we observe negligible Joule heating within the nanotube lattice itself and instead heating occurs in the insulating substrate directly via a remote-scattering heating efect. Using fnite element analysis, we estimate a remote heating parameter, β, as the ratio of the power dissipated directly in the substrate to the total power applied. The extracted parameters show two distinct bias ranges; a low bias regime where about 85% of the power is dissipated directly into the substrate and a high bias regime where β decreases, indicating the onset of traditional Joule heating within the nanotube. Analysis shows that this reduction is consistent with enhanced scattering of charge carriers by optical phonons within the nanotube. The results provide insights into heat dissipation mechanisms of Joule heated nanotube devices that are more complex than a simple heat dissipation mechanism dominated by acoustic phonons, which opens new possibilities for engineering nanoelectronics with improved thermal management. With the ongoing miniaturization of electronics, operating temperature has become a dominant parameter dic- tating the efciency and performance of useful devices1–3. Tere has been signifcant interest in developing carbon nanotube (CNT) based electronics4–8 due to their small size and unique electrical and thermal properties9,10.
    [Show full text]
  • 10.05.05 Fundamental Equations; Equilibrium and the Second Law
    3.012 Fundamentals of Materials Science Fall 2005 Lecture 8: 10.05.05 Fundamental Equations; Equilibrium and the Second Law Today: LAST TIME ................................................................................................................................................................................ 2 THERMODYNAMIC DRIVING FORCES: WRITING A FUNDAMENTAL EQUATION ........................................................................... 3 What goes into internal energy?.......................................................................................................................................... 3 THE FUNDAMENTAL EQUATION FOR THE ENTROPY................................................................................................................... 5 INTRODUCTION TO THE SECOND LAW ....................................................................................................................................... 6 Statements of the second law ............................................................................................................................................... 6 APPLYING THE SECOND LAW .................................................................................................................................................... 8 Heat flows from hot objects to cold objects ......................................................................................................................... 8 Thermal equilibrium ...........................................................................................................................................................
    [Show full text]
  • Thermal Physics
    PHYS 1001: Thermal Physics Stream 1: Streams 2: Dr Helen Johnston Dr Pulin Gong Rm 213 Physics Rm 434 Madsen [email protected] [email protected] Module Outline • Lectures • Lab + tutorials + assignments • “University Physics”, Young & Freedman • Ch. 17: Temperature and heat • Ch. 18: Thermal properties of matter • Ch. 19: The first law of thermodynamics • Ch. 20: The second law of thermodynamics Module Outline 1. Temperature and heat 2. Thermal expansion 3. Heat capacity and latent heat 4. Methods of heat transfer 5. Ideal gases and the kinetic theory model 6, 7. The first law of thermodynamics 8, 9. 2nd Law of Thermodynamics and entropy 10. Heat engines, and Review What is temperature? • “Hotness” and “coldness” • How do we measure it? Thermodynamic systems State variables (macroscopic): T, p, V, M, ρ etc. A thermodynamic system is a quantity of matter of fixed identity, with surroundings and a boundary. Thermodynamic systems Systems can be • open – mass and energy can flow through boundary • closed – only energy can flow through boundary • isolated – nothing gets through boundary Thermal equilibrium • If two objects are in thermal contact, the hotter object cools and the cooler object warms until no further changes take place è the objects are in thermal equilibrium. What is temperature? Temperature is the value of the property that is same for two objects, after they’ve been in contact long enough and are in thermal equilibrium. Zeroth law of thermodynamics If A and B are each in thermal equilibrium with C, then A and B are in thermal equilibrium with each other.
    [Show full text]
  • Thermodynamics
    CHAPTER TWELVE THERMODYNAMICS 12.1 INTRODUCTION In previous chapter we have studied thermal properties of matter. In this chapter we shall study laws that govern thermal energy. We shall study the processes where work is 12.1 Introduction converted into heat and vice versa. In winter, when we rub 12.2 Thermal equilibrium our palms together, we feel warmer; here work done in rubbing 12.3 Zeroth law of produces the ‘heat’. Conversely, in a steam engine, the ‘heat’ Thermodynamics of the steam is used to do useful work in moving the pistons, 12.4 Heat, internal energy and which in turn rotate the wheels of the train. work In physics, we need to define the notions of heat, 12.5 First law of temperature, work, etc. more carefully. Historically, it took a thermodynamics long time to arrive at the proper concept of ‘heat’. Before the 12.6 Specific heat capacity modern picture, heat was regarded as a fine invisible fluid 12.7 Thermodynamic state filling in the pores of a substance. On contact between a hot variables and equation of body and a cold body, the fluid (called caloric) flowed from state the colder to the hotter body! This is similar to what happens 12.8 Thermodynamic processes when a horizontal pipe connects two tanks containing water 12.9 Heat engines up to different heights. The flow continues until the levels of 12.10 Refrigerators and heat water in the two tanks are the same. Likewise, in the ‘caloric’ pumps picture of heat, heat flows until the ‘caloric levels’ (i.e., the 12.11 Second law of temperatures) equalise.
    [Show full text]
  • ENGINEERING THERMODYNAMICS BME-12(III Sem
    ENGINEERING THERMODYNAMICS BME-12(III Sem. ME) by Devesh Kumar Assistant Professor Mechanical Engineering Department UNIT-I Fundamental Concepts and Definitions Introduction and definition of thermodynamics, Microscopic and Macroscopic approaches, Concept of continuum .Systems, surroundings, Control system, control volume and control surface, Properties, intensive & extensive and state of Thermodynamic system. point and path properties, process, cycle , Thermodynamic equilibrium, Reversibility and irreversibility, Quasi static process, Energy and its forms, Work and heat, Ideal & Real gas, Dalton’s law, Amagat’s law, Property of mixture of gases. Zeroth law of thermodynamics Zeroth law of thermodynamics, Temperature and its’ measurement. First law of thermodynamics for closed system Introduction of first law of thermodynamics, Calculation of work in various processes and sign convention, work, Joules’ experiment, Internal energy and enthalpy DEFINITION OF THERMODYNAMICS • Thermodynamics is an axiomatic science which deals with the relations among heat, work and properties of system which are in equilibrium. It describes state and changes in state of physical systems. Or • Thermodynamics is the science that deals with the interaction between energy and material systems. • ‘’Thermodynamics is the branch of physical science that deals with the various phenomena of energy and related properties of matter, especially of the laws of transformations of heat into other forms of energy and vice-versa.” Thermodynamics, basically entails four laws or axioms known as Zeroth, First, Second and Third law of thermodynamics. ➢ The First law throws light on concept of internal energy. ➢ The Zeroth law deals with thermal equilibrium and establishes a concept of temperature. ➢ The Second law indicates the limit of converting heat into work and introduces the principle of increase of entropy.
    [Show full text]
  • Infrared Thermography for Temperature Measurement and Non-Destructive Testing
    Sensors 2014, 14, 12305-12348; doi:10.3390/s140712305 OPEN ACCESS sensors ISSN 1424-8220 www.mdpi.com/journal/sensors Review Infrared Thermography for Temperature Measurement and Non-Destructive Testing Ruben´ Usamentiaga 1;*, Pablo Venegas 2, Jon Guerediaga 2, Laura Vega 2, Julio Molleda 1 and Francisco G. Bulnes 1 1 Department of Computer Science and Engineering, University of Oviedo, Campus de Viesques 33204 Gijon,´ Asturias, Spain; E-Mails: [email protected] (J.M.); [email protected] (F.G.B.) 2 Aeronautical Technology Centre (CTA), Parque Tecnologico´ de Alava,´ Juan de la Cierva 1, 01510 Minano,˜ Spain; E-Mails: [email protected] (P.V.); [email protected] (J.G.); [email protected] (L.V.) * Author to whom correspondence should be addressed; E-Mail: [email protected]; Tel.: +34-985-182626; Fax: +34-985-181986. Received: 23 December 2013; in revised form: 26 June 2014 / Accepted: 30 June 2014 / Published: 10 July 2014 Abstract: The intensity of the infrared radiation emitted by objects is mainly a function of their temperature. In infrared thermography, this feature is used for multiple purposes: as a health indicator in medical applications, as a sign of malfunction in mechanical and electrical maintenance or as an indicator of heat loss in buildings. This paper presents a review of infrared thermography especially focused on two applications: temperature measurement and non-destructive testing, two of the main fields where infrared thermography-based sensors are used. A general introduction to infrared thermography and the common procedures for temperature measurement and non-destructive testing are presented. Furthermore, developments in these fields and recent advances are reviewed.
    [Show full text]
  • Chapter 7. Phenomena in Thermal Transport in Fuels
    NEA/NSC/R(2015)5 Chapter 7. Phenomena in thermal transport in fuels A. Chernatynskiy1, A. El-Azab2, J.S. Tulenko1, S.R. Phillpot1 1University of Florida, US, 2Purdue University, US Abstract Thermal transport in nuclear fuels is a key performance metric that affects not only the power output, but is also an important consideration in potential accident situations. While the fundamental theory of the thermal transport in crystalline solids was extensively developed in the 1950s and 1960s, the pertinent analytic approaches contained significant simplifications of the physical processes. While these approaches enabled estimates of the thermal conductivity in bulk materials with microstructure, they were not comprehensive enough to provide the detailed guidance needed for the in-pile fuel performance. Rather, this guidance has come from data painfully accumulated over 50 years of experiments on irradiated uranium dioxide, the most widely used nuclear fuel. At this point, a fundamental theoretical understanding of the interplay between the microstructure and thermal conductivity of irradiated uranium dioxide fuel is still lacking. In this chapter, recent advances are summarised in the modelling approaches for thermal transport of uranium dioxide fuel. Being computational in nature, these modelling approaches can, at least in principle, describe in detail virtually all mechanisms affecting thermal transport at the atomistic level, while permitting the coupling of the atomistic-level simulations to the mesoscale continuum theory and thus enable the capture of the impact of microstructural evolution in fuel on thermal transport. While the subject of current studies is uranium dioxide, potential applications of the methods described in this chapter extend to the thermal performance of other fuel forms.
    [Show full text]