# HEAT AND MASS TRANSFER

Save this PDF as:

Size: px
Start display at page:

Download "HEAT AND MASS TRANSFER"

## Transcription

1 MEL242 HEAT AND MASS TRANSFER Prabal Talukdar Associate Professor Department of Mechanical Engineering g IIT Delhi MECH/IITD

2 Course Coordinator: Dr. Prabal Talukdar Room No: III, Course webpage: Pre-requisite: Fluid Mechanics (AML 160) Lectures: Tue, Wed, Fri: a.m. (Room No: IV LT1) Tut: p.m. (Tentative Room no: III352 MEL 242: Heat and Mass Transfer (3-1-0) Syllabus (for total 42 lectures) Introduction and basics of to heat transfer: Modes of heat transfer, Fourier s law, conductivity, diffusivity. Heat conduction equation: 1D Heat conduction, General heat conduction equation, Boundary and initial conditions, Heat generation. Steady heat conduction: Heat conduction in plane wall, cylinder, sphere, network analysis, critical radius of insulation, heat transfer from fins. Transient heat conduction: Lumped system analysis, transient heat conduction in large plane walls, long cylinders and spheres with spatial effect, Hil Heisler and Grober charts Numerical methods of heat conduction: Finite difference formulation, numerical methods for 1D and 2D steady state heat conduction. ( 10 lectures) Introduction to convection: Fundamentals, Velocity and thermal boundary layer, laminar, turbulent flows, conservation equations for mass, momentum and energy, solution of boundary layer equations, Analogy between heat and momentum transfer, Non-dimensional numbers External heat transfer: Drag and heat transfer, parallel flow over flat plates, flow across cylinders and spheres Internal heat transfer: Mean velocity and mean temperature, entrance region, constant heat flux and temperature condition in pipe flow, Hagen Poiseuille flow, Turbulent flow and heat transfer Natural/free convection: Equation of motion of Grashof number, natural convection over surfaces and inside enclosures ( 13 lectures)

3 Boiling and condensation: Boiling heat transfer, pool boiling, flow boiling, condensation heat transfer, film condensation, heat transfer correlations. ( 4 lectures) Heat Exchangers: Types of heat exchangers, overall heat transfer coefficient, analysis of heat exchangers, the log mean temperature method, ε-ntu method. ( 4 lectures) Introduction to radiation: Fundamentals, radiative properties of opaque surfaces, Intensity, emissive power, radiosity, i Planck s law, Wien s displacement law, Black and Gray surfaces, Emissivity, i i absorptivity, i Spectral and directional variations, Stephan Boltzmann law, Kirchhoff s law View factors: Definitions and relations, radiation heat transfer between two black surfaces, between diffuse gray surfaces, network method above two surfaces, re-radiating surface, radiation shield, radiation effects on temperature measurements. ( 7 lectures) Mass Transfer: Introduction, analogy between heat and mass transfer, mass diffusion, Fick s Law, boundary conditions, steady mass diffusion through a wall, cylinder and sphere, water vapour migration in buildings, transient mass diffusion, mass transfer in a moving medium, diffusion of vapor through a stationary gas: Stefan Flow ( 4 lectures) Evaluation: Tuts and Quiz (2 nos): 20% (Closed note, book) Quiz Quiz 1 Quiz 2 Minor Test I: 20% (Open note, closed book) Tentative Date August 27 November 5 Minor Test II: 25% (Open note, closed book) Major Test: 35% (Open note, closed book) Total: 100% Textbook: Fundamental of Heat and Mass Transfer: F. P. Incropera and D. P.Dewitt Heat Transfer: Yunus A. Cengel Heat Transfer: J.P. Holmann

4 Heat Transfer as a Course Has a reputation for being one of the most challenging, fundamental, conceptual courses in ME. It is the heart of thermal engineering i Why?? Physically diverse: thermodynamics, material science, diffusion theory, fluid mechanics, radiation theory Higher-level math: vector calculus, ODEs, PDEs, numerical methods Physically elusive: heat is invisible; developing intuition takes time Appropriate assumptions: required to simplify and solve most problems However, Heat Transfer is interesting, fun, and readily applicable to the real world

5 Heat Transfer Applications Heat transfer is commonly encountered in engineering systems and other aspects of life, and one does not need to go very far to see some application areas of heat transfer.

6 Human body

7 Heat Transfer - Thermodynamics Thermodynamics is concerned with the amount of heat transfer as a system undergoes a process from one equilibrium state to another, and it gives no indication about how long the process will take. A thermodynamic analysis simply tells us how much heat must be transferred to realize a specified change of state to satisfy the conservation of energy principle. We are normally interested in how long it takes for the hot coffee in a thermos to cool to a certain temperature, which cannot be determined from a thermodynamic analysis alone. Determining the rates of heat transfer to or from a system and thus the times of cooling or heating, as well as the variation of the temperature, is the subject of heat transfer

8 Definition Heat transfer is energy transfer due to a temperature difference in a medium or between two or more media Different types of heat transfer processes are called different modes of heat transfer Conduction heat transfer is due to a temperature gradient in a stationary medium or media Convection heat transfer occurs between a surface and a moving fluid at different temperatures Radiation heat transfer occurs due to emission of energy in the form of electromagnetic eti waves by all bodies above absolute zero temperature Net radiation heat transfer occurs when there exists a temperature difference between two or more surfaces emitting radiation energy

9 Conduction Conduction heat transfer is due to random molecular and atomic vibrational, rotational and translational motions High temperature and more energetic molecules vibrate more and transfer energy to less energetic particles as a result of molecular collisions or interactions Q & Q x The heat flux (a vector) (W / m 2 ) is characterized by a transport property know as the Thermal Conductivity, k (W / m K) W = watts m = Meters K = temperature in Kelvin

10 Conduction is the transfer of energy from the more energetic particles of a substance to the adjacent less energetic ones as a result of interactions between the particles. Conduction can take place in solids, liquids, or gases. In gases and liquids, conduction is due to the collisions and diffusion of the molecules during their random motion. In solids, it is due to the combination of vibrations of the molecules in a lattice and the energy transport by free electrons The rate of heat conduction through a medium depends on the geometry of the medium, its thickness, and the material of the medium, as well as the temperature difference across the medium

11 Q& cond Fourier s Law = ka T 2 T1 ΔT = ka Δxx Δxx (W) In the limiting case of x 0, the equation above reduces to the differential form Q& cond = ka dt dx (W) The negative sign ensures that heat transfer in the positive x direction is a positive quantity Fourier s law of heat conduction after J. Fourier, who expressed it first in his heat transfer text in 1822 T 1 = T 2 =

12 Thermal Conductivity Specific heat C p is a measure of a material s ability to store thermal energy. For example, C p = 4.18 kj/kg C for water and C p = 0.45 kj/kg C for iron at room temperature, which indicates that water can store almost 10 times the energy that iron can per unit mass. Likewise, the thermal conductivity k is a measure of a material s ability to conduct heat. For example, k = W/m C for water and k = 80.2 W/m C for iron at room temperature, which indicates that iron conducts cts heat more than 100 times faster than water can. Thus water is a poor heat conductor relative to iron, although water is an excellent medium to store thermal energy

13 Range of Thermal Conductivity The thermal conductivities of gases such as air vary by a factor of 10 4 from those of pure metals such as copper. Note that pure crystals and metals have the highest thermal conductivities, and gases and insulating materials the lowest.

14 A simple experimental setup to determine the thermal conductivity of a material.

15 The range of thermal conductivity of various materials at room temperature

16 The thermal conductivity of a substance is normally highest in the solid phase and lowest in the gas phase. Unlike gases, the thermal conductivities of most liquids id decrease with increasing i temperature, with water being a notable exception. In solids, heat conduction is due to two effects: the lattice vibrational waves induced by the vibrational a motions o of the molecules es positioned at relatively fixed positions in a periodic manner called a lattice, and the energy transported via the free flow of electrons in the solid. The thermal conductivity of a solid is obtained by adding the lattice and electronic components. The relatively high thermal conductivities of pure metals are primarily due to the electronic component.

17 The lattice component of thermal conductivity strongly depends on the way the molecules are arranged Unlike metals, which are good electrical and heat conductors, crystalline solids such as diamond d and semiconductors such as silicon are good heat conductors but poor electrical conductors. As a result, such materials find widespread use in the electronics industry. For example, diamond, which is a highly ordered crystalline solid, has the highest known thermal conductivity at room temperature. Even small amounts in a pure metal of foreign molecules that are good conductors themselves seriously disrupt the flow of heat in that tmetal. For example, the thermal conductivity of steel containing just 1 percent of chrome is 62 W/m C, while the thermal conductivities of iron and chromium are 83 and 95 W/m C,

18 The variation of the thermal conductivity of various solids, liquids, and gases with temperature (from White)

19 Thermal Diffusivity The product ρc p, which is frequently encountered in heat transfer analysis, is called the heat capacity of a material. Both the specific heat C p and the heat capacity ρc p represent the heat storage capability of a material. But C p expresses it per unit mass whereas ρc p expresses it per unit volume, as can be noticed from their units J/kg C and J/m 3 C, respectively. Another material property that appears in the transient heat conduction analysis is the thermal diffusivity, which represents how fast heat diffuses through a material and is defined as The larger the thermal diffusivity, the faster the propagation of heat into the medium. A small value of thermal diffusivity means that heat is mostly absorbed by the material and a small amount of heat will be conducted further

20 Note that the thermal diffusivity ranges from 0.14 x 10-6 m 2 /s for water to 174 x 10-6 m 2 /s for silver, which is a difference of more than a thousand times. Also note that the thermal diffusivities of beef and water are the same. This is not surprising, since meat as well as fresh vegetables and fruits are mostly water, and thus they possess the thermal properties of water.

21 Forced Convection Natural Convection Boiling Condensation

22 Convection Convection heat transfer involves both energy transfer due to random molecular motions and by bulk motion of the fluid Convection heat transfer includes both forced convection and natural convection In convection heat transfer, the transfer of heat is between a surface and a moving fluid (liquid or gas), when they are at different temperatures. The rate of transfer is given by Newton s Law of Cooling. q '' = h(t s T ) T q Moving fluid T s T s > T

23 Typical values of convection heat transfer coefficient i Process h (W / m 2 K) Free Convection Gases 2-25 Liquids Forced Convection Gases Liquids 50-20,000 with Phase Change Boiling or Condensation ,000

24 Radiation All surfaces of finite temperature emit energy in the form of electromagnetic waves In the absence of an intervening medium, there is a heat transfer by radiation between two surfaces at different temperatures The maximum flux, E (W / m 2 ), at which radiation may be emitted from a blackbody surface is given by: Stefan Boltzmann Law E = σ 4 b T s E b where T s E b or E = Surface emissive power (W / m 2 ) T = absolute temperature (K) σ = Stefan-Boltzmann constant = 5.67 x 10-8 (W / m 2 K 4)

25 For a real surface: E = εσt s 4 For a surface with absorptivity α,, the incident radiation (G, W/m 2 ) that is absorbed by the surface is given by: G abs = α G G where G = incident radiation (W / m 2 ) G abs T = absolute temperature (K) ε = surface emissivity (0 ε 1) α = surface absorptivity (0 α 1)

26 For a gray surface α = ε When radiant energy is incident on a transparent surface, it can be absorbed, reflected, or transmitted through the material. Hence, G = G absorbed + G transmitted + G reflected = ( α + τ + ρ)g α + τ + ρ = 1 where ρ = materials surface reflectivity τ = materials transmissivity

27 Consider a small gray surface at temperature T s that is completely enclosed by the surroundings at temperature T sur. The net rate of radiation heat transfer from the surface is: q sur q s T sur '' 4 q 4 rad = Es αgsur = εσts ασtsur T s q '' rad q = A = εσ T 4 s ασ T 4 sur = h r ( T T ) s sur Where h r is the radiation heat transfer coefficient, W / m 2 K r 2 2 = ( )( ) ε σ T + T T T h + s sur s sur

28 Conduction example

29 Calculate the heat flux from your hand when it is exposed to moving air and water, assuming the surface temperature of your hand is 30 C. Convection example

30 Radiation ex. An instrumentation package has a spherical outer surface of diameter D = 100 mm and emissivity ε = The package is placed in a large space simulation chamber whose walls are maintained at 77 K. If the operation of the electronic components is restricted to the temperature range of 40 T 85 C, what is the range of acceptable power dissipation for the package?

### Heat Transfer and Energy

What is Heat? Heat Transfer and Energy Heat is Energy in Transit. Recall the First law from Thermodynamics. U = Q - W What did we mean by all the terms? What is U? What is Q? What is W? What is Heat Transfer?

More information

### HEAT TRANSFER IM0245 3 LECTURE HOURS PER WEEK THERMODYNAMICS - IM0237 2014_1

COURSE CODE INTENSITY PRE-REQUISITE CO-REQUISITE CREDITS ACTUALIZATION DATE HEAT TRANSFER IM05 LECTURE HOURS PER WEEK 8 HOURS CLASSROOM ON 6 WEEKS, HOURS LABORATORY, HOURS OF INDEPENDENT WORK THERMODYNAMICS

More information

### 1. Heat and Mass Transfer, Fundamentals & Applications, Fourth Edition, Cengel, Y., Ghajar, A. McGraw-Hill, 2011, ISBN

University of Bridgeport Course Syllabus MEEG 463 Advanced Heat Transfer Tuesday: 6-8:30PM, Mandeville 221 Jani Macari Pallis, Ph.D. jpallis@bridgeport.edu (203) 576-4579 Office Hours: Monday 9-11AM, Thursday

More information

### Fundamentals of Heat and Mass Transfer

2008 AGI-Information Management Consultants May be used for personal purporses only or by libraries associated to dandelon.com network. SIXTH EDITION Fundamentals of Heat and Mass Transfer FRANK P. INCROPERA

More information

### Energy Transport. Focus on heat transfer. Heat Transfer Mechanisms: Conduction Radiation Convection (mass movement of fluids)

Energy Transport Focus on heat transfer Heat Transfer Mechanisms: Conduction Radiation Convection (mass movement of fluids) Conduction Conduction heat transfer occurs only when there is physical contact

More information

### Steady Heat Conduction

Steady Heat Conduction In thermodynamics, we considered the amount of heat transfer as a system undergoes a process from one equilibrium state to another. hermodynamics gives no indication of how long

More information

### For one dimensional heat transfer by conduction in the x-direction only, the heat transfer rate is given by

Chapter.3-1 Modes of Heat Transfer Conduction For one dimensional heat transfer by conduction in the -direction only, the heat transfer rate is given by Q ka d (.3-4) In this epression, k is a property

More information

### Fundamentals of THERMAL-FLUID SCIENCES

Fundamentals of THERMAL-FLUID SCIENCES THIRD EDITION YUNUS A. CENGEL ROBERT H. TURNER Department of Mechanical JOHN M. CIMBALA Me Graw Hill Higher Education Boston Burr Ridge, IL Dubuque, IA Madison, Wl

More information

### Lecture 30 - Chapter 6 Thermal & Energy Systems (Examples) 1

Potential Energy ME 101: Thermal and Energy Systems Chapter 7 - Examples Gravitational Potential Energy U = mgδh Relative to a reference height Increase in elevation increases U Decrease in elevation decreases

More information

### Chapter 18 Temperature, Heat, and the First Law of Thermodynamics. Problems: 8, 11, 13, 17, 21, 27, 29, 37, 39, 41, 47, 51, 57

Chapter 18 Temperature, Heat, and the First Law of Thermodynamics Problems: 8, 11, 13, 17, 21, 27, 29, 37, 39, 41, 47, 51, 57 Thermodynamics study and application of thermal energy temperature quantity

More information

### Heat Transfer From A Heated Vertical Plate

Heat Transfer From A Heated Vertical Plate Mechanical and Environmental Engineering Laboratory Department of Mechanical and Aerospace Engineering University of California at San Diego La Jolla, California

More information

### Basic Equations, Boundary Conditions and Dimensionless Parameters

Chapter 2 Basic Equations, Boundary Conditions and Dimensionless Parameters In the foregoing chapter, many basic concepts related to the present investigation and the associated literature survey were

More information

### Heating In Agitated & Non-Agitated Vessels

Heating In Agitated & Non-Agitated Vessels IBD/BFBiMidland Section Engineering Symposium on Heat Transfer and Refrigeration Burton-on-Trent Jan 2014 Mark Phillips Briggs of Burton Contents Heat Energy

More information

### Principle of Thermal Imaging

Section 8 All materials, which are above 0 degrees Kelvin (-273 degrees C), emit infrared energy. The infrared energy emitted from the measured object is converted into an electrical signal by the imaging

More information

### Chapter 3 Temperature and Heat

Chapter 3 Temperature and Heat In Chapter, temperature was described as an intensive property of a system. In common parlance, we understand temperature as a property which is related to the degree of

More information

### Lecture 9, Thermal Notes, 3.054

Lecture 9, Thermal Notes, 3.054 Thermal Properties of Foams Closed cell foams widely used for thermal insulation Only materials with lower conductivity are aerogels (tend to be brittle and weak) and vacuum

More information

### The First Law of Thermodynamics: Closed Systems. Heat Transfer

The First Law of Thermodynamics: Closed Systems The first law of thermodynamics can be simply stated as follows: during an interaction between a system and its surroundings, the amount of energy gained

More information

### TEACHER BACKGROUND INFORMATION THERMAL ENERGY

TEACHER BACKGROUND INFORMATION THERMAL ENERGY In general, when an object performs work on another object, it does not transfer all of its energy to that object. Some of the energy is lost as heat due to

More information

### The Three Heat Transfer Modes in Reflow Soldering

Section 5: Reflow Oven Heat Transfer The Three Heat Transfer Modes in Reflow Soldering There are three different heating modes involved with most SMT reflow processes: conduction, convection, and infrared

More information

### Natural Convection. Buoyancy force

Natural Convection In natural convection, the fluid motion occurs by natural means such as buoyancy. Since the fluid velocity associated with natural convection is relatively low, the heat transfer coefficient

More information

### Temperature and Heat. Chapter 17. PowerPoint Lectures for University Physics, Twelfth Edition Hugh D. Young and Roger A. Freedman

Chapter 17 Temperature and Heat PowerPoint Lectures for University Physics, Twelfth Edition Hugh D. Young and Roger A. Freedman Lectures by James Pazun Modified by P. Lam 6_17_2012 Topics for Chapter 17

More information

### Greenhouse Effect and the Global Energy Balance

Greenhouse Effect and the Global Energy Balance Energy transmission ( a a refresher) There are three modes of energy transmission to consider. Conduction: the transfer of energy in a substance by means

More information

### 1. A 4 kg aluminum rod has a temperature of 100 C. It is placed into an insulated bucket containing 50 kg of water at 0 C. (T 0 C) = (4 kg) 900 J

Physics 101 Quiz #8 Solution November 20, 2002 Name 20 Minutes. Box your answers. density specific heat thermal coefficient of capacity conductivity thermal expansion (kg/m 3 ) (J/kg C) (J/m s C) (1/ C)

More information

### Differential Relations for Fluid Flow. Acceleration field of a fluid. The differential equation of mass conservation

Differential Relations for Fluid Flow In this approach, we apply our four basic conservation laws to an infinitesimally small control volume. The differential approach provides point by point details of

More information

### Name: Class: Date: 10. Some substances, when exposed to visible light, absorb more energy as heat than other substances absorb.

Name: Class: Date: ID: A PS Chapter 13 Review Modified True/False Indicate whether the statement is true or false. If false, change the identified word or phrase to make the statement true. 1. In all cooling

More information

### Microscale and Nanoscale Heat Transfer

Sebastian Volz (Ed.) Microscale and Nanoscale Heat Transfer With 144 Figures and 7 Tables In Collaboration with Remi Carminati, Patrice Chantrenne, Stefan Dilhaire, Severine Gomez, Nathalie Trannoy, and

More information

### Lecture 3 Fluid Dynamics and Balance Equa6ons for Reac6ng Flows

Lecture 3 Fluid Dynamics and Balance Equa6ons for Reac6ng Flows 3.- 1 Basics: equations of continuum mechanics - balance equations for mass and momentum - balance equations for the energy and the chemical

More information

### Mechanisms of Heat Transfer. Amin Sabzevari

Mechanisms of Heat Transfer Amin Sabzevari Outline Definition of Heat and Temperature Conduction, Convection, Radiation Demonstrations and Examples What is Heat? Heat is the spontaneous flow of energy

More information

### Every mathematician knows it is impossible to understand an elementary course in thermodynamics. ~V.I. Arnold

Every mathematician knows it is impossible to understand an elementary course in thermodynamics. ~V.I. Arnold Radiation Radiation: Heat energy transmitted by electromagnetic waves Q t = εσat 4 emissivity

More information

### Carbon Cable. Sergio Rubio Carles Paul Albert Monte

Carbon Cable Sergio Rubio Carles Paul Albert Monte Carbon, Copper and Manganine PhYsical PropERTieS CARBON PROPERTIES Carbon physical Properties Temperature Coefficient α -0,0005 ºC-1 Density D 2260 kg/m3

More information

### FLUID DYNAMICS. Intrinsic properties of fluids. Fluids behavior under various conditions

FLUID DYNAMICS Intrinsic properties of fluids Fluids behavior under various conditions Methods by which we can manipulate and utilize the fluids to produce desired results TYPES OF FLUID FLOW Laminar or

More information

### - the total energy of the system is found by summing up (integrating) over all particles n(ε) at different energies ε

Average Particle Energy in an Ideal Gas - the total energy of the system is found by summing up (integrating) over all particles n(ε) at different energies ε - with the integral - we find - note: - the

More information

### Study the following diagrams of the States of Matter. Label the names of the Changes of State between the different states.

Describe the strength of attractive forces between particles. Describe the amount of space between particles. Can the particles in this state be compressed? Do the particles in this state have a definite

More information

### Earth s Energy Balance & the Greenhouse Effect

Earth s Energy Balance & the Greenhouse Effect Outline: The Earth s Energy Balance: Electromagnetic Spectrum: Ultraviolet (UV) Visible Infrared (IR) Blackbody Radiation Albedo (reflectivity) Greenhouse

More information

### Understanding Solar Energy Teacher Page

Understanding Solar Energy Teacher Page Student Objective The student: will be able to calculate the calorie heat gain for several different containers given containers of several different materials will

More information

### THE WAY TO SOMEWHERE. Sub-topics. Diffusion Diffusion processes in industry

THE WAY TO SOMEWHERE Sub-topics 1 Diffusion Diffusion processes in industry RATE PROCESSES IN SOLIDS At any temperature different from absolute zero all atoms, irrespective of their state of aggregation

More information

### Thermodynamics AP Physics B. Multiple Choice Questions

Thermodynamics AP Physics B Name Multiple Choice Questions 1. What is the name of the following statement: When two systems are in thermal equilibrium with a third system, then they are in thermal equilibrium

More information

### The First Law of Thermodynamics

The First aw of Thermodynamics Q and W are process (path)-dependent. (Q W) = E int is independent of the process. E int = E int,f E int,i = Q W (first law) Q: + heat into the system; heat lost from the

More information

### University of Waterloo Department of Civil Engineering. CE507 Building Science and Technology

University of Waterloo Department of Civil Engineering CE507 Building Science and Technology PHYSICS QUIZ # SOLUTIONS Question : Buildings [0] i) Provide a short but completely general definition of the

More information

### Lecture 2: Radiation/Heat in the atmosphere

Lecture 2: Radiation/Heat in the atmosphere TEMPERATURE is a measure of the internal heat energy of a substance. The molecules that make up all matter are in constant motion. By internal heat energy, we

More information

### Module 1 : Conduction. Lecture 5 : 1D conduction example problems. 2D conduction

Module 1 : Conduction Lecture 5 : 1D conduction example problems. 2D conduction Objectives In this class: An example of optimization for insulation thickness is solved. The 1D conduction is considered

More information

### Radiation Heat Transfer

Applied Heat Transfer Part Three Dr. Ahmad RAMAZANI S.A. Associate Professor Sharif University of Technology انتقال حرارت کاربردی احمد رمضانی سعادت ا بادی Autumn, 1385 (2006) (Applications) Building Dryer

More information

### Heat Transfer. Phys101 Lectures 35, 36. Key points: Heat as Energy Transfer Specific Heat Heat Transfer: Conduction, Convection, Radiation

Phys101 Lectures 35, 36 Heat Transfer Key points: Heat as Energy Transfer Specific Heat Heat Transfer: Conduction, Convection, Radiation Ref: 16-1,3,4,10. Page 1 19-1 Heat as Energy Transfer We often speak

More information

### Chapter 4: Transfer of Thermal Energy

Chapter 4: Transfer of Thermal Energy Goals of Period 4 Section 4.1: To define temperature and thermal energy Section 4.2: To discuss three methods of thermal energy transfer. Section 4.3: To describe

More information

### Lecture 12. Physical Vapor Deposition: Evaporation and Sputtering Reading: Chapter 12. ECE 6450 - Dr. Alan Doolittle

Lecture 12 Physical Vapor Deposition: Evaporation and Sputtering Reading: Chapter 12 Evaporation and Sputtering (Metalization) Evaporation For all devices, there is a need to go from semiconductor to metal.

More information

### Conductive and Radiative Heat Transfer in Insulators

Conductive and Radiative Heat Transfer in Insulators Akhan Tleoubaev, Ph.D. LaserComp, Inc., December 1998 Heat transfer for most thermal insulation materials occurs via both conduction and radiation.

More information

### 4. Introduction to Heat & Mass Transfer

4. Introduction to Heat & Mass Transfer This section will cover the following concepts: A rudimentary introduction to mass transfer. Mass transfer from a molecular point of view. Fundamental similarity

More information

### The Greenhouse Effect

The Greenhouse Effect The Greenhouse Effect Solar and terrestrial radiation occupy different ranges of the electromagnetic spectrum, that we have been referring to as shortwave and longwave. The Greenhouse

More information

### Statistical Mechanics, Kinetic Theory Ideal Gas. 8.01t Nov 22, 2004

Statistical Mechanics, Kinetic Theory Ideal Gas 8.01t Nov 22, 2004 Statistical Mechanics and Thermodynamics Thermodynamics Old & Fundamental Understanding of Heat (I.e. Steam) Engines Part of Physics Einstein

More information

### Radiation Transfer in Environmental Science

Radiation Transfer in Environmental Science with emphasis on aquatic and vegetation canopy media Autumn 2008 Prof. Emmanuel Boss, Dr. Eyal Rotenberg Introduction Radiation in Environmental sciences Most

More information

### Active Infrared Thermography in Non-destructive Testing

Active Infrared Thermography in Non-destructive Testing M. Hain, J. Bartl, V. Jacko Institute of Measurement Science Slovak Academy of Sciences, Bratislava, Slovak Republic e-mail: hain@savba.sk Outline

More information

### Copper, Zinc and Brass (an alloy of Cu and Zn) have very similar specific heat capacities. Why should this be so?

Thermal Properties 1. Specific Heat Capacity The heat capacity or thermal capacity of a body is a measure of how much thermal energy is required to raise its temperature by 1K (1 C). This will depend on

More information

### Chapter 8 Steady Incompressible Flow in Pressure Conduits

Chapter 8 Steady Incompressible Flow in Pressure Conduits Outline 8.1 Laminar Flow and turbulent flow Reynolds Experiment 8.2 Reynolds number 8.3 Hydraulic Radius 8.4 Friction Head Loss in Conduits of

More information

### Science Standard Articulated by Grade Level Strand 5: Physical Science

Concept 1: Properties of Objects and Materials Classify objects and materials by their observable properties. Kindergarten Grade 1 Grade 2 Grade 3 Grade 4 PO 1. Identify the following observable properties

More information

### Comsol Laboration: Heat Conduction in a Chip

Comsol Laboration: Heat Conduction in a Chip JO, CSC January 11, 2012 1 Physical configuration A chip on a circuit board is heated inside and cooled by convection by the surrounding fluid. We consider

More information

### ENSC 283 Introduction and Properties of Fluids

ENSC 283 Introduction and Properties of Fluids Spring 2009 Prepared by: M. Bahrami Mechatronics System Engineering, School of Engineering and Sciences, SFU 1 Pressure Pressure is the (compression) force

More information

### Physics 9e/Cutnell. correlated to the. College Board AP Physics 1 Course Objectives

Physics 9e/Cutnell correlated to the College Board AP Physics 1 Course Objectives Big Idea 1: Objects and systems have properties such as mass and charge. Systems may have internal structure. Enduring

More information

### Chapter 10 Temperature and Heat

Chapter 10 Temperature and Heat What are temperature and heat? Are they the same? What causes heat? What Is Temperature? How do we measure temperature? What are we actually measuring? Temperature and Its

More information

### Chemistry 433. The Third Law of Thermodynamics. Residual Entropy. CO: an Imperfect Crystal. Question. Question. Lecture 12 The Third Law

Chemistry 433 Lecture 12 he hird Law he hird Law of hermodynamics he third law of thermodynamics states that every substance has a positive entropy, but at zero Kelvin the entropy is zero for a perfectly

More information

### 1. Radiative Transfer. 2. Spectrum of Radiation. 3. Definitions

1. Radiative Transfer Virtually all the exchanges of energy between the earth-atmosphere system and the rest of the universe take place by radiative transfer. The earth and its atmosphere are constantly

More information

### Heat Transfer: Radiation

Heat Transfer: Radiation Heat transfer occurs by three mechanisms: conduction, convection, and radiation. We have discussed conduction in the past two lessons. In this lesson, we will discuss radiation.

More information

### Lecture 7 Heat Transfer & Thermal Insulation. J. G. Weisend II

Lecture 7 Heat Transfer & Thermal Insulation J. G. Weisend II Goals Introduce conduction, convection & radiation heat transfer as they apply to cryogenics Describe design techniques to reduce heat transfer

More information

### Resistivity. V A = R = L ρ (1)

Resistivity Electric resistance R of a conductor depends on its size and shape as well as on the conducting material. The size- and shape-dependence was discovered by Georg Simon Ohm and is often treated

More information

### EXPERIMENT 3a HEAT TRANSFER IN NATURAL CONVECTION

EXPERIMENT 3a HEAT TRANSFER IN NATURAL CONVECTION CONTENT: 1. Aim 2. Objective 3. Introduction 4. Theory/Background 5. Apparatus 6. Experimental Procedure 7. Precautions 8. Calculations 9. Uncertainty

More information

### Module 2 : Convection. Lecture 20a : Illustrative examples

Module 2 : Convection Lecture 20a : Illustrative examples Objectives In this class: Examples will be taken where the concepts discussed for heat transfer for tubular geometries in earlier classes will

More information

### Temperature Scales. temperature scales Celsius Fahrenheit Kelvin

Ch. 10-11 Concept Ch. 10 #1, 3, 7, 8, 9, 11 Ch11, # 3, 6, 11 Problems Ch10 # 3, 5, 11, 17, 21, 24, 25, 29, 33, 37, 39, 43, 47, 59 Problems: CH 11 # 1, 2, 3a, 4, 5, 6, 9, 13, 15, 22, 25, 27, 28, 35 Temperature

More information

### 1. The Kinetic Theory of Matter states that all matter is composed of atoms and molecules that are in a constant state of constant random motion

Physical Science Period: Name: ANSWER KEY Date: Practice Test for Unit 3: Ch. 3, and some of 15 and 16: Kinetic Theory of Matter, States of matter, and and thermodynamics, and gas laws. 1. The Kinetic

More information

### ME 144: Heat Transfer Convection Relations for External Flows. J. M. Meyers

ME 144: Heat Transfer Convection Relations for External Flows Empirical Correlations Generally, convection correlations for external flows are determined experimentally using controlled lab conditions

More information

### CHAPTER 2 Energy and Earth

CHAPTER 2 Energy and Earth This chapter is concerned with the nature of energy and how it interacts with Earth. At this stage we are looking at energy in an abstract form though relate it to how it affect

More information

### MASTER OF SCIENCE IN MECHANICAL ENGINEERING

MASTER OF SCIENCE IN MECHANICAL ENGINEERING Introduction There are over 22 schools in Mindanao that offer Bachelor of Science in Mechanical Engineering and majority of their faculty members do not have

More information

### Entrance Conditions. Chapter 8. Islamic Azad University

Chapter 8 Convection: Internal Flow Islamic Azad University Karaj Branch Entrance Conditions Must distinguish between entrance and fully developed regions. Hydrodynamic Effects: Assume laminar flow with

More information

### Chapter 24. Wave Optics

Chapter 24 Wave Optics Wave Optics The wave nature of light is needed to explain various phenomena. Interference Diffraction Polarization The particle nature of light was the basis for ray (geometric)

More information

### KINETIC MOLECULAR THEORY OF MATTER

KINETIC MOLECULAR THEORY OF MATTER The kinetic-molecular theory is based on the idea that particles of matter are always in motion. The theory can be used to explain the properties of solids, liquids,

More information

### In today s world of wireless communications

TUTORIAL RF CERAMIC CHIP CAPACITORS IN HIGH RF POWER APPLICATIONS Reprinted with permission of MICROWAVE JOURNAL from the April 2000 issue. 2000 Horizon House Publications, Inc. In today s world of wireless

More information

### ENERGY CONSERVATION The First Law of Thermodynamics and the Work/Kinetic-Energy Theorem

PH-211 A. La Rosa ENERGY CONSERVATION The irst Law of Thermodynamics and the Work/Kinetic-Energy Theorem ENERGY TRANSER of ENERGY Heat-transfer Q Macroscopic external Work W done on a system ENERGY CONSERVATION

More information

### The Nature of Electromagnetic Radiation

II The Nature of Electromagnetic Radiation The Sun s energy has traveled across space as electromagnetic radiation, and that is the form in which it arrives on Earth. It is this radiation that determines

More information

### Integration of a fin experiment into the undergraduate heat transfer laboratory

Integration of a fin experiment into the undergraduate heat transfer laboratory H. I. Abu-Mulaweh Mechanical Engineering Department, Purdue University at Fort Wayne, Fort Wayne, IN 46805, USA E-mail: mulaweh@engr.ipfw.edu

More information

### Blackbody radiation. Main Laws. Brightness temperature. 1. Concepts of a blackbody and thermodynamical equilibrium.

Lecture 4 lackbody radiation. Main Laws. rightness temperature. Objectives: 1. Concepts of a blackbody, thermodynamical equilibrium, and local thermodynamical equilibrium.. Main laws: lackbody emission:

More information

### Lecture 24 - Surface tension, viscous flow, thermodynamics

Lecture 24 - Surface tension, viscous flow, thermodynamics Surface tension, surface energy The atoms at the surface of a solid or liquid are not happy. Their bonding is less ideal than the bonding of atoms

More information

### Iterative calculation of the heat transfer coefficient

Iterative calculation of the heat transfer coefficient D.Roncati Progettazione Ottica Roncati, via Panfilio, 17 44121 Ferrara Aim The plate temperature of a cooling heat sink is an important parameter

More information

### Fluids and Solids: Fundamentals

Fluids and Solids: Fundamentals We normally recognize three states of matter: solid; liquid and gas. However, liquid and gas are both fluids: in contrast to solids they lack the ability to resist deformation.

More information

### Chapter 5 Light and Matter: Reading Messages from the Cosmos

Chapter 5 Light and Matter: Reading Messages from the Cosmos Messages Interactions of Light and Matter The interactions determine everything we see, including what we observe in the Universe. What is light?

More information

### Final Exam Review Questions PHY Final Chapters

Final Exam Review Questions PHY 2425 - Final Chapters Section: 17 1 Topic: Thermal Equilibrium and Temperature Type: Numerical 12 A temperature of 14ºF is equivalent to A) 10ºC B) 7.77ºC C) 25.5ºC D) 26.7ºC

More information

### Heat Transfer Prof. Dr. Ale Kumar Ghosal Department of Chemical Engineering Indian Institute of Technology, Guwahati

Heat Transfer Prof. Dr. Ale Kumar Ghosal Department of Chemical Engineering Indian Institute of Technology, Guwahati Module No. # 04 Convective Heat Transfer Lecture No. # 03 Heat Transfer Correlation

More information

### CBE 6333, R. Levicky 1 Review of Fluid Mechanics Terminology

CBE 6333, R. Levicky 1 Review of Fluid Mechanics Terminology The Continuum Hypothesis: We will regard macroscopic behavior of fluids as if the fluids are perfectly continuous in structure. In reality,

More information

### The examination rubric is: Answer THREE questions, from FIVE offered. All questions carry equal weight.

MODULE DESCRIPTOR MECHGM06 Heat Transfer and Heat Systems Code: MECHGM06 Alt. Codes(s) MECHGR06, MECHM007 Title: Heat Transfer and Heat Systems Level: M UCL Credits/ECTS: 15/6 Start: September End: March

More information

### Convection, Conduction & Radiation

Convection, Conduction & Radiation There are three basic ways in which heat is transferred: convection, conduction and radiation. In gases and liquids, heat is usually transferred by convection, in which

More information

### INTRODUCTION TO FLUID MECHANICS

INTRODUCTION TO FLUID MECHANICS SIXTH EDITION ROBERT W. FOX Purdue University ALAN T. MCDONALD Purdue University PHILIP J. PRITCHARD Manhattan College JOHN WILEY & SONS, INC. CONTENTS CHAPTER 1 INTRODUCTION

More information

### Chapter 1. Governing Equations of Fluid Flow and Heat Transfer

Chapter 1 Governing Equations of Fluid Flow and Heat Transfer Following fundamental laws can be used to derive governing differential equations that are solved in a Computational Fluid Dynamics (CFD) study

More information

### A. Kinetic Molecular Theory (KMT) = the idea that particles of matter are always in motion and that this motion has consequences.

I. MOLECULES IN MOTION: A. Kinetic Molecular Theory (KMT) = the idea that particles of matter are always in motion and that this motion has consequences. 1) theory developed in the late 19 th century to

More information

### Chapter 5: Diffusion. 5.1 Steady-State Diffusion

: Diffusion Diffusion: the movement of particles in a solid from an area of high concentration to an area of low concentration, resulting in the uniform distribution of the substance Diffusion is process

More information

### Boltzmann Distribution Law

Boltzmann Distribution Law The motion of molecules is extremely chaotic Any individual molecule is colliding with others at an enormous rate Typically at a rate of a billion times per second We introduce

More information

### Physics Final Exam Chapter 13 Review

Physics 1401 - Final Exam Chapter 13 Review 11. The coefficient of linear expansion of steel is 12 10 6 /C. A railroad track is made of individual rails of steel 1.0 km in length. By what length would

More information

### FIND: Characteristic length and Biot number. Validity of lumped capacitance approximation.

Mech 302 Heat Transfer HW5 Solution 1. (Problem 5.5 in the Book except for part (e)) For each of the following cases, determine an appropriate characteristic length Lc and the corresponding Biot number

More information

### CLASSICAL CONCEPT REVIEW 8

CLASSICAL CONCEPT REVIEW 8 Kinetic Theory Information concerning the initial motions of each of the atoms of macroscopic systems is not accessible, nor do we have the computational capability even with

More information

### Mass Transfer in Laminar & Turbulent Flow. Mass Transfer Coefficients

Mass Transfer in Laminar & Turbulent Flow Mass Transfer Coefficients 25 MassTransfer.key - January 3, 204 Convective Heat & Mass Transfer T T w T in bulk and T w near wall, with a complicated T profile

More information

### Energy and Energy Transformations Test Review

Energy and Energy Transformations Test Review Completion: 1. Mass 13. Kinetic 2. Four 14. thermal 3. Kinetic 15. Thermal energy (heat) 4. Electromagnetic/Radiant 16. Thermal energy (heat) 5. Thermal 17.

More information

### Lecture 8: Radiation Spectrum. Radiation. Electromagnetic Radiation

Lecture 8: Radiation Spectrum The information contained in the light we receive is unaffected by distance The information remains intact so long as the light doesn t run into something along the way Since

More information

### ES 106 Laboratory # 2 HEAT AND TEMPERATURE

ES 106 Laboratory # 2 HEAT AND TEMPERATURE Introduction Heat transfer is the movement of heat energy from one place to another. Heat energy can be transferred by three different mechanisms: convection,

More information

### Thermal diffusivity and conductivity - an introduction to theory and practice

Thermal diffusivity and conductivity - an introduction to theory and practice Utrecht, 02 October 2014 Dr. Hans-W. Marx Linseis Messgeräte GmbH Vielitzer Str. 43 D-95100 Selb / GERMANY www.linseis.com

More information