By ablation we mean the recession of a surface due to heating, usually by a hot gas. It is the key process for
|
|
- Dennis Shepherd
- 5 years ago
- Views:
Transcription
1 16.50 Lecture 15 Subject: Ablative cooling By ablation we mean the recession of a surface due to heating, usually by a hot gas. It is the key process for a) Re-entry heat shields b) Solid propellant nozzles c) Rocket case insulation d) Fire-proofing skyscrapers' structures Consider a hot gas flowing over a surface which can 1) evaporate, and ) whose vapor can react with the external flow A heat balance at the surface gives q s = q w - (ρv) w Δh w (1) where the heat of ablation, Δh w =h w h s, in J/kg, can include a heat of vaporization and decomposition and q w is the heat flux from the fluid boundary layer. Let us assume that it is useful to write q w = ρ e (H e + ue - Hw) where H w is the total enthalpy for the wall material at the wall temperature, and H e =c pg T ge is the gas specific enthalpy at the temperature T ge just outside the boundary layer. Notice that this generalizes our previous expression for heat transfer by replacing the total enthalpy for the static enthalpy; this is of general validity for high-speed flows. By energy conservation in the core flow, u H e + e = c pgt c. 1
2 Then the heat transfer to the solid is ue s q s = ρ e (H e + - H w ) - (ρv) w (h w - h ) Since q s is the heat flux available to heat the wall, it is clear that the evaporation reduces the wall heat flux, i.e. the heat flux into the solid. Now what determines (ρv) w? First note that (ρv) w = rρ s where r is our "recession rate". Consider a "thermal wave" propagating into the solid. We will now work in the receding frame, in which we can assume a steady situation. If the recession rate is r(m/s), we see solid material moving at! y = "r, and convecting a heat flux. Then, if there is no local heat generation, d dt (!k s! r" s T ) = 0 dy dy dt which integrates to k s + r T = const. = r! st w, or dy " d(t! Tw" ) r ks + (T! T w" ) = o (! =, heat diffusivity, in m /s) dy # " s T! T w" = (T w! T w )e! # y " dt " r The heat flux at at y = o is q s =!k s $ = k s (T w! T w& ), giving dy # y= o % r q s = r(t w " T w# ), or r q = s (T w " T w# ) So returning to our expression for the heat flux to the wall, r (T w " T w# ) q s = c pg (T c " T w ) " r#h w! c pg (T c " T w )! r c (T " T ) s pg c w r =, = (T w " T w# ) + $hw (T w " T w# ) + $h w %& You may compare this to Sutton pg. 510 Eq Now how does (ρv) w influence? Physically, we know that the vapor comes off the wall with u=0, so it will tend to retard the flow near the wall.
3 Quantitatively, Lees says, for small surface blowoff effect, B 1. 8,30 (ρv) w = c!! 500 J / Kg / K, B = o e B!1 pg 0. 0 ρ e o while Sutton quotes Lees as giving for the larger blowoffs = 1.7 B < B < 100 o These give the same trends, but somewhat different numbers. We adopt here Lees r B formulation: We had =", so B =! =! B o e "1 or e B!1 =" # B =!n(1 +") so finally, +- % c pg (T c " T w ) (/- r =,!n '1 + *0 o -. & (T w " Tw# ) + $h w )-1 (1) and then % c (T " T ) ( q pg c w s sr) ( T w " T w# ) = 0 (T w " T w# )!n '1+ * & (T w w# ) + $h w ) (1 ) m! p At the throat, ( ue ) = = c t * w, and hence r, is maximum. A t c Numerically, one often sees!h w >> (T w " T w# ), and also! <<1. This would leave us with the approximations c pg (Tc # T! r " w ) s o $h w ()! o (3) and going back to the surface heat balance, q s! o, i.e., to the first order, the heat does not penetrate below the ablating layer, which is as intended. 3
4 Equations (1) or () can be used to select the proper thickness of the ablative (sacrificial) layer, once the burn time is given:! Abl = r t b. Now let us look at some numerical examples, to show the magnitudes of the terms: Joule A. For carbon, Hf g = 17 kcal/gmole=60 x 10 6 kg cal h w - h s = 1 = 15,000 g 1. 8, 30 cpg!! 500 J / Kg / K, ρ s 000 kg / m 3 kg / m and assume T c -T w =1,000K. p Now ρ e =! " 0.65 RT p RT 10 5 (p c atm) kg 58 (p c atm) 8.3x10 3 m s (3000) 0 Taking p c =100 atm and =0.001, we then calculate,500 *1,000 r!,000 " 60 "10 6 " 58 "100 " = 1. "10 #4 m / s = 0.1 mm / s So in 100 sec., the change in the surface is 1 mm = 1. cm. This is of the right magnitude, but most important is to see what it depends on. B. For rubber h w -h s 10,000 cal/gm mole. For an approximate empirical formula C 10 H 0, this gives per unit mass cal Joule = 70 80, g kg Also c p 1 cal/g 4,000 Joule/kg K So now we would get about 100 times the regression rate for carbon. In this case though, if the rubber is used in the casing of a solid rocket engine then ρ e << 1 (ρ e ) throat, maybe by 100, so the net regression may end up being similar. 4
5 MIT OpenCourseWare Introduction to Propulsion Systems Spring 01 For information about citing these materials or our Terms of Use, visit:
Rocket Propulsion Prof. K. Ramamurthi Department of Mechanical Engineering Indian Institute of Technology, Madras
Rocket Propulsion Prof. K. Ramamurthi Department of Mechanical Engineering Indian Institute of Technology, Madras Lecture 32 Efficiencies due to Mixture Ratio Distribution and Incomplete Vaporization (Refer
More informationPropulsion Systems Design MARYLAND. Rocket engine basics Solid rocket motors Liquid rocket engines. Hybrid rocket engines Auxiliary propulsion systems
Propulsion Systems Design Rocket engine basics Solid rocket motors Liquid rocket engines Monopropellants Bipropellants Propellant feed systems Hybrid rocket engines Auxiliary propulsion systems 2004 David
More informationUnified Quiz: Thermodynamics
Fall 004 Unified Quiz: Thermodynamics November 1, 004 Calculators allowed. No books allowed. A list of equations is provided. Put your name on each page of the exam. Read all questions carefully. Do all
More informationIntroduction to Heat and Mass Transfer. Week 10
Introduction to Heat and Mass Transfer Week 10 Concentration Boundary Layer No concentration jump condition requires species adjacent to surface to have same concentration as at the surface Owing to concentration
More informationIntroduction to Aerospace Engineering
Introduction to Aerospace Engineering Lecture slides Challenge the future 3-0-0 Introduction to Aerospace Engineering Aerodynamics 5 & 6 Prof. H. Bijl ir. N. Timmer Delft University of Technology 5. Compressibility
More informationUNIFIED ENGINEERING Fall 2003 Ian A. Waitz
Ian A. Waitz Problem T6. (Thermodynamics) Consider the following thermodynamic cycle. Assume all processes are quasi-static and involve an ideal gas. 3 p Const. volume heat addition 2 adiabatic expansion
More informationRelationship to Thermodynamics. Chapter One Section 1.3
Relationship to Thermodynamics Chapter One Section 1.3 Alternative Formulations Alternative Formulations Time Basis: CONSERVATION OF ENERGY (FIRST LAW OF THERMODYNAMICS) An important tool in heat transfer
More informationPROBLEM 14.6 ( )( ) (b) Applying a species balance to a control volume about the hydrogen, dt 6 dt 6RAT dt 6RT dt
PROBLEM 14.6 KNOWN: Pressure and temperature of hydrogen stored in a spherical steel tank of prescribed diameter and thickness. FIND: (a) Initial rate of hydrogen mass loss from the tank, (b) Initial rate
More informationChapter 10 Test Form B
Chapter 10 Test Form A 1. B 2. A 3. A 4. B 5. D 6. B 7. B 8. A 9. A 10. A 11. B 12. D 13. A 14. C 15. No, heat and cold do not flow between objects. Energy transferred between objects changes the temperature
More informationTheory. Humidity h of an air-vapor mixture is defined as the mass ratio of water vapor and dry air,
Theory Background In a cooling tower with open water circulation, heat is removed from water because of the material and heat exchange between the water and the ambient air. The cooling tower is a special
More informationHeat processes. Heat exchange
Heat processes Heat exchange Heat energy transported across a surface from higher temperature side to lower temperature side; it is a macroscopic measure of transported energies of molecular motions Temperature
More informationPTT 277/3 APPLIED THERMODYNAMICS SEM 1 (2013/2014)
PTT 77/3 APPLIED THERMODYNAMICS SEM 1 (013/014) 1 Energy can exist in numerous forms: Thermal Mechanical Kinetic Potential Electric Magnetic Chemical Nuclear The total energy of a system on a unit mass:
More informationApplied Gas Dynamics Flow With Friction and Heat Transfer
Applied Gas Dynamics Flow With Friction and Heat Transfer Ethirajan Rathakrishnan Applied Gas Dynamics, John Wiley & Sons (Asia) Pte Ltd c 2010 Ethirajan Rathakrishnan 1 / 121 Introduction So far, we have
More informationPhysics 101: Lecture 25 Heat
Final Physics 101: Lecture 25 Heat Today s lecture will cover Textbook Chapter 14.1-14.5 Physics 101: Lecture 25, Pg 1 Internal Energy Energy of all molecules including Random motion of individual molecules»
More informationHomework - Lecture 11.
Homework - Lecture 11. Name: Topic: Heat Capacity and Specific Heat Type: Numerical 1. Two liquids, A and B, are mixed together, and the resulting temperature is 22 C. If liquid A has mass m and was initially
More informationModeling and Analysis of Dynamic Systems
Modeling and Analysis of Dynamic Systems Dr. Guillaume Ducard Fall 2017 Institute for Dynamic Systems and Control ETH Zurich, Switzerland G. Ducard c 1 / 46 Outline 1 Lecture 6: Electromechanical Systems
More informationRocket Thermodynamics
Rocket Thermodynamics PROFESSOR CHRIS CHATWIN LECTURE FOR SATELLITE AND SPACE SYSTEMS MSC UNIVERSITY OF SUSSEX SCHOOL OF ENGINEERING & INFORMATICS 25 TH APRIL 2017 Thermodynamics of Chemical Rockets ΣForce
More informationChapter 5. Mass and Energy Analysis of Control Volumes
Chapter 5 Mass and Energy Analysis of Control Volumes Conservation Principles for Control volumes The conservation of mass and the conservation of energy principles for open systems (or control volumes)
More informationAME 436. Energy and Propulsion. Lecture 15 Propulsion 5: Hypersonic propulsion
AME 436 Energy and Propulsion Lecture 5 Propulsion 5: Hypersonic propulsion Outline!!!!!! Why hypersonic propulsion? What's different about it? Conventional ramjet heat addition at M
More informationRecap. There are 3 different temperature scales: Celsius, Kelvin, and Fahrenheit
Recap Temperature, T, is related to the average kinetic energy of each atom/molecule the given material consists of: The ideal gas law relates pressure to density and temperature: There are 3 different
More informationPropulsion Systems Design
Propulsion Systems Design Rocket engine basics Survey of the technologies Propellant feed systems Propulsion systems design 1 2011 David L. Akin - All rights reserved http://spacecraft.ssl.umd.edu Propulsion
More informationENGINEERING OF NUCLEAR REACTORS. Tuesday, October 9 th, 2014, 1:00 2:30 p.m.
.31 ENGINEERING OF NUCLEAR REACTORS Tuesday, October 9 th, 014, 1:00 :30 p.m. OEN BOOK QUIZ 1 (solutions) roblem 1 (50%) Loss o condensate pump transient in a LWR condenser i) Consider the seaater in the
More informationPropulsion Systems Design MARYLAND. Rocket engine basics Survey of the technologies Propellant feed systems Propulsion systems design
Design Rocket engine basics Survey of the technologies Propellant feed systems Propulsion systems design 2005 David L. Akin - All rights reserved http://spacecraft.ssl.umd.edu Overview of the Design Process
More informationVersion 001 HW 15 Thermodynamics C&J sizemore (21301jtsizemore) 1
Version 001 HW 15 Thermodynamics C&J sizemore 21301jtsizemore 1 This print-out should have 38 questions. Multiple-choice questions may continue on the next column or page find all choices before answering.
More informationDifferential equations of mass transfer
Differential equations of mass transfer Definition: The differential equations of mass transfer are general equations describing mass transfer in all directions and at all conditions. How is the differential
More information12.009/ Problem Set 2
12.009/18.352 Problem Set 2 Due Thursday, 26 February 2015 100 points total Problem 1: 15 pts (a,b)=(10,5) Problem 2: 45 pts (a,b,c,d,e,f)=(5,5,5,10,10,10) Problem 3: 40 pts (a,b,c,d,e,f)=(5,5,5,5,10,10)
More informationDiffusional Growth of Liquid Phase Hydrometeros.
Diffusional Growth of Liquid Phase Hydrometeros. I. Diffusional Growth of Liquid Phase Hydrometeors A. Basic concepts of diffusional growth. 1. To understand the diffusional growth of a droplet, we must
More informationThermodynamics Introduction and Basic Concepts
Thermodynamics Introduction and Basic Concepts by Asst. Prof. Channarong Asavatesanupap Mechanical Engineering Department Faculty of Engineering Thammasat University 2 What is Thermodynamics? Thermodynamics
More informationTypes of Energy Calorimetry q = mc T Thermochemical Equations Hess s Law Spontaneity, Entropy, Gibb s Free energy
Unit 7: Energy Outline Types of Energy Calorimetry q = mc T Thermochemical Equations Hess s Law Spontaneity, Entropy, Gibb s Free energy Energy Energy is the ability to do work or produce heat. The energy
More informationHeat Transfer There are three mechanisms for the transfer of heat:
Heat Transfer There are three mechanisms for the transfer of heat: Conduction Convection Radiation CONDUCTION is a diffusive process wherein molecules transmit their kinetic energy to other molecules by
More informationTest Case Baseline Results
1 Test Case Baseline Results Ablation Test-Case Series #2 Feb. 28th Mar. 1st 2012, Lexington, Kentucky Tim Risch & Chris Kostyk NASA Dryden Flight Research Center February 28, 2012 Objective Present baseline
More informationAerodynamics. Basic Aerodynamics. Continuity equation (mass conserved) Some thermodynamics. Energy equation (energy conserved)
Flow with no friction (inviscid) Aerodynamics Basic Aerodynamics Continuity equation (mass conserved) Flow with friction (viscous) Momentum equation (F = ma) 1. Euler s equation 2. Bernoulli s equation
More informationDevelopment of an evaporation boundary condition for DSMC method with application to meteoroid entry
Development of an evaporation boundary condition for DSMC method with application to meteoroid entry F. Bariselli, S. Boccelli, A. Frezzotti, A. Hubin, T. Magin Annual METRO meeting 29th November 2016
More informationME Thermodynamics I
Homework - Week 01 HW-01 (25 points) Given: 5 Schematic of the solar cell/solar panel Find: 5 Identify the system and the heat/work interactions associated with it. Show the direction of the interactions.
More informationThermodynamics of solids 5. Unary systems. Kwangheon Park Kyung Hee University Department of Nuclear Engineering
Thermodynamics of solids 5. Unary systems Kwangheon ark Kyung Hee University Department of Nuclear Engineering 5.1. Unary heterogeneous system definition Unary system: one component system. Unary heterogeneous
More informationAAE SOLID ROCKET PROPULSION (SRP) SYSTEMS
7. SOLID ROCKET PROPULSION (SRP) SYSTEMS Ch7 1 7.1 INTRODUCTION 7.1 INTRODUCTION Ch7 2 APPLICATIONS FOR SRM APPLICATIONS FOR SRM Strap-On Boosters for Space Launch Vehicles, Upper Stage Propulsion System
More informationChapter 5 Thermochemistry
Chapter 5 Thermochemistry Section 17.1 The Flow of Energy Heat and Work OBJECTIVES: Explain how energy, heat, and work are related. 2 Section 17.1 The Flow of Energy Heat and Work OBJECTIVES: Classify
More informationChapter 17 Thermochemistry
Chapter 17 Thermochemistry Section 17.1 The Flow of Energy Heat and Work OBJECTIVES: Explain how energy, heat, and work are related. 2 Section 17.1 The Flow of Energy Heat and Work OBJECTIVES: Classify
More informationHomework # cm. 11 cm cm. 100 cm. MAE Propulsion Systems, II
Homework #3.1 Nitrous Oxide HTPB Hybrid Rocket design Desired Thrust of 8 knt Operate near optimal mixture ratio (based on C*) Nozzle A/A * =16.4, exit diameter = 19.17 cm, Nozzle Exit Divergence angle
More information8.21 The Physics of Energy Fall 2009
MIT OpenCourseWare http://ocw.mit.edu 8.21 The Physics of Energy Fall 2009 For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms. 8.21 Lecture 9 Heat Engines
More informationLecture 23. Specific Heat and Phase Changes
Lecture 23 Specific Heat and Phase Changes Today s Topics: Heat and Temperature Change Specific heat Heat and Phase Change Latent heat Heat and Temperature Change Heat is energy that flows from a higher-temperature
More informationEnergy Transformations
Thermochemistry Energy Transformations Thermochemistry - concerned with heat changes that occur during chemical reactions Energy - capacity for doing work or supplying heat weightless, odorless, tasteless
More informationAME 513. " Lecture 8 Premixed flames I: Propagation rates
AME 53 Principles of Combustion " Lecture 8 Premixed flames I: Propagation rates Outline" Rankine-Hugoniot relations Hugoniot curves Rayleigh lines Families of solutions Detonations Chapman-Jouget Others
More informationRocket Propulsion Prof. K. Ramamurthi Department of Mechanical Engineering Indian Institute of Technology, Madras
Rocket Propulsion Prof. K. Ramamurthi Department of Mechanical Engineering Indian Institute of Technology, Madras Lecture 23 Burn Rate of Solid Propellants and Equilibrium Pressure in Solid Propellant
More informationPropulsion Systems Design
Propulsion Systems Design Rocket engine basics Survey of the technologies Propellant feed systems Propulsion systems design 1 2016 David L. Akin - All rights reserved http://spacecraft.ssl.umd.edu Liquid
More informationVI. Porous Media. Lecture 34: Transport in Porous Media
VI. Porous Media Lecture 34: Transport in Porous Media 4/29/20 (corrected 5/4/2 MZB) Notes by MIT Student. Conduction In the previous lecture, we considered conduction of electricity (or heat conduction
More informationDesign And Analysis Of Thrust Chamber Of A Cryogenic Rocket Engine S. Senthilkumar 1, Dr. P. Maniiarasan 2,Christy Oomman Jacob 2, T.
Design And Analysis Of Thrust Chamber Of A Cryogenic Rocket Engine S. Senthilkumar 1, Dr. P. Maniiarasan 2,Christy Oomman Jacob 2, T. Vinitha 2 1 Research Scholar, Department of Mechanical Engineering,
More informationName: Class: Date: ID: A
Name: Class: _ Date: _ ID: A Chpter 17 review Multiple Choice Identify the choice that best completes the statement or answers the question. 1. Which of these phase changes is an endothermic process? a.
More informationThermodynamics ENGR360-MEP112 LECTURE 7
Thermodynamics ENGR360-MEP11 LECTURE 7 Thermodynamics ENGR360/MEP11 Objectives: 1. Conservation of mass principle.. Conservation of energy principle applied to control volumes (first law of thermodynamics).
More informationSOLID ROCKET MOTOR INTERNAL BALLISTICS SIMULATION USING DIFFERENT BURNING RATE MODELS
U.P.B. Sci. Bull., Series D, Vol. 76, Iss. 4, 2014 ISSN 1454-2358 SOLID ROCKET MOTOR INTERNAL BALLISTICS SIMULATION USING DIFFERENT BURNING RATE MODELS Marius Ionuţ MĂRMUREANU 1 The burning rate of solid
More information1. Fill in the blanks with the following: kinetic, potential, chemical, thermal. One word will be used twice.
Thermo Worksheets Name Class Period Types of Energy and the Law of Conservation of Energy 1. Fill in the blanks with the following: kinetic, potential, chemical, thermal. One word will be used twice. Solar
More informationOutline. Aim. Gas law. Pressure. Scale height Mixing Column density. Temperature Lapse rate Stability. Condensation Humidity.
Institute of Applied Physics University of Bern Outline A planetary atmosphere consists of different gases hold to the planet by gravity The laws of thermodynamics hold structure as vertical coordinate
More informationThe First Law of Thermodynamics. By: Yidnekachew Messele
The First Law of Thermodynamics By: Yidnekachew Messele It is the law that relates the various forms of energies for system of different types. It is simply the expression of the conservation of energy
More informationME 354 Tutorial, Week#13 Reacting Mixtures
ME 354 Tutorial, Week#13 Reacting Mixtures Question 1: Determine the mole fractions of the products of combustion when octane, C 8 H 18, is burned with 200% theoretical air. Also, determine the air-fuel
More informationPhysics 1501 Lecture 35
Physics 1501: Lecture 35 Todays Agenda Announcements Homework #11 (Dec. 2) and #12 (Dec. 9): 2 lowest dropped Honors students: see me after the class! Todays topics Chap.16: Temperature and Heat» Latent
More informationGreenhouse Steady State Energy Balance Model
Greenhouse Steady State Energy Balance Model The energy balance for the greenhouse was obtained by applying energy conservation to the greenhouse system as a control volume and identifying the energy terms.
More informationLect 22. Radial Flow Turbines. Prof. Bhaskar Roy, Prof. A M Pradeep, Department of Aerospace, IIT Bombay
Lecture Lect Radial Flow Turbines Lect Radial inflow turbines, which look similar to centrifugal compressor, are considered suitable for application in small aircraft engines. In many applications a radial
More information4.1 LAWS OF MECHANICS - Review
4.1 LAWS OF MECHANICS - Review Ch4 9 SYSTEM System: Moving Fluid Definitions: System is defined as an arbitrary quantity of mass of fixed identity. Surrounding is everything external to this system. Boundary
More informationPROBLEM 1.2 ( ) 25 C 15 C dx L 0.30 m Ambient air temperature, T2 (C)
PROBLEM 1.2 KNOWN: Inner surface temperature and thermal conductivity of a concrete wall. FIND: Heat loss by conduction through the wall as a function of ambient air temperatures ranging from -15 to 38
More informationThermal Energy Final Exam Fall 2002
16.050 Thermal Energy Final Exam Fall 2002 Do all eight problems. All problems count the same. 1. A system undergoes a reversible cycle while exchanging heat with three thermal reservoirs, as shown below.
More informationGases. Properties of Gases Kinetic Molecular Theory of Gases Pressure Boyle s and Charles Law The Ideal Gas Law Gas reactions Partial pressures.
Gases Properties of Gases Kinetic Molecular Theory of Gases Pressure Boyle s and Charles Law The Ideal Gas Law Gas reactions Partial pressures Gases Properties of Gases All elements will form a gas at
More informationLecture notes: Interception and evapotranspiration
Lecture notes: Interception and evapotranspiration I. Vegetation canopy interception (I c ): Portion of incident precipitation (P) physically intercepted, stored and ultimately evaporated from vegetation
More informationS15--AP Phys Q4--Heat-Thermo Ch13_14_15 PRACTICE
Name: Class: Date: S5--AP Phys Q4--Heat-Thermo Ch3_4_5 PRACTICE Multiple Choice Identify the choice that best completes the statement or answers the question.. Which of the following is a thermodynamic
More informationLecture 3a: Surface Energy Balance
Lecture 3a: Surface Energy Balance Instructor: Prof. Johnny Luo http://www.sci.ccny.cuny.edu/~luo Surface Energy Balance 1. Factors affecting surface energy balance 2. Surface heat storage 3. Surface
More informationIntroduction to Aerospace Engineering
Introduction to Aerospace Engineering Lecture slides Challenge the future 4-0-0 Introduction to Aerospace Engineering Aerodynamics 3 & 4 Prof. H. Bijl ir. N. Timmer Delft University of Technology Challenge
More informationLecture notes for /12.586, Modeling Environmental Complexity. D. H. Rothman, MIT October 22, 2014
Lecture notes for 12.086/12.586, Modeling Environmental Complexity D. H. Rothman, MIT October 22, 2014 Contents 1 Origin of biogeochemical cycles 1 1.1 The carbon cycle......................... 1 1.1.1
More informationI. The Nature of Energy A. Energy
I. The Nature of Energy A. Energy is the ability to do work or produce heat. It exists in 2 forms: 1. Potential energy is energy due to the composition or position of an object. 2. Kinetic energy is energy
More informationUnit II Thermal Physics Introduction- Modes of Heat Transfer Normally there are three modes of transfer of heat from one place to another viz., conduction, convection and radiation. Conduction : Conduction
More informationName: Applied Physics II Exam 2 Winter Multiple Choice ( 8 Points Each ):
Name: e-mail: Applied Physics II Exam 2 Winter 2006-2007 Multiple Choice ( 8 Points Each ): 1. A cowboy fires a silver bullet ( specific heat c = 234 J / kg O C ) with a muzzle speed of 200 m/s into a
More informationConvective Heat and Mass Transfer Prof. A.W. Date Department of Mechanical Engineering Indian Institute of Technology, Bombay
Convective Heat and Mass Transfer Prof. A.W. Date Department of Mechanical Engineering Indian Institute of Technology, Bombay Module No. # 01 Lecture No. # 32 Stefan Flow Model We are now familiar with
More informationLecture 24. Paths on the pv diagram
Goals: Lecture 24 Chapter 17 Apply heat and energy transfer processes Recognize adiabatic processes Chapter 18 Follow the connection between temperature, thermal energy, and the average translational kinetic
More informationR11.3. Diffusion and Reaction Facilitated Heat Transfer
Chapter 11 Professional Reference Shelf R11.3. Diffusion and Reaction Facilitated Heat Transfer When diffusion is coupled with a reversible reaction contained between two surfaces, there is an increase
More informationTheories for Mass Transfer Coefficients
Mass Transfer Theories for Mass Transfer Coefficients Lecture 9, 5..7, r. K. Wegner 9. Basic Theories for Mass Transfer Coefficients Aim: To find a theory behind the empirical mass-transfer correlations
More informationChapter 5: Thermochemistry. Molecular Kinetic Energy -Translational energy E k, translational = 1/2mv 2 -Rotational energy 5.
Chapter 5: Thermochemistry 1. Thermodynamics 2. Energy 3. Specific Heat 4. Enthalpy 5. Enthalpies of Reactions 6. Hess s Law 7. State Functions 8. Standard Enthalpies of Formation 9. Determining Enthalpies
More informationChapter 18 Temperature, Heat, and the First Law of Thermodynamics. Thermodynamics and Statistical Physics
Chapter 18 Temperature, Heat, and the First Law of Thermodynamics Thermodynamics and Statistical Physics Key contents: Temperature scales Thermal expansion Temperature and heat, specific heat Heat and
More informationChapter 5: The First Law of Thermodynamics: Closed Systems
Chapter 5: 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
More informationIntroduction to Heat and Mass Transfer. Week 9
Introduction to Heat and Mass Transfer Week 9 補充! Multidimensional Effects Transient problems with heat transfer in two or three dimensions can be considered using the solutions obtained for one dimensional
More informationP 1 P * 1 T P * 1 T 1 T * 1. s 1 P 1
ME 131B Fluid Mechanics Solutions to Week Three Problem Session: Isentropic Flow II (1/26/98) 1. From an energy view point, (a) a nozzle is a device that converts static enthalpy into kinetic energy. (b)
More information6. Transport phenomena. Basel, 2008
6. Transport phenomena Basel, 2008 6. Transport phenomena 1. Introduction 2. Phenomenological equations for transport properties 3. Transport properties of a perfect gas 4. Diffusion in a fluid 5. Measurement
More informationThermal Properties, Moisture Diffusivity Chpt 8
Processing and Storage of Ag Products Heating Cooling Combination of heating and cooling Grain dried for storage Noodles dried Fruits/Vegetables rapidly cooled Vegetables are blanched, maybe cooked and
More informationThe Tropical Atmosphere: Hurricane Incubator
The Tropical Atmosphere: Hurricane Incubator Images from journals published by the American Meteorological Society are copyright AMS and used with permission. A One-Dimensional Description of the Tropical
More informationPROCESS SYSTEMS ENGINEERING Dr.-Ing. Richard Hanke-Rauschenbach
Otto-von-Guerice University Magdeburg PROCESS SYSTEMS ENGINEERING Dr.-Ing. Richard Hane-Rauschenbach Project wor No. 1, Winter term 2011/2012 Sample Solution Delivery of the project handout: Wednesday,
More informationEnergy. Different types of energy exist (heat, potential, kinetic, chemical, nuclear etc.)
Change in Energy Energy Different types of energy exist (heat, potential, kinetic, chemical, nuclear etc.) Heat - the energy transferred between objects that are at different temperatures. Unit of heat
More informationSimulation of Free Convection with Conjugate Heat Transfer
Simulation of Free Convection with Conjugate Heat Transfer Hong Xu, Chokri Guetari, Kurt Svihla ANSYS, Inc. Abstract This study focuses on free convective and conjugate heat transfer in a naturally ventilated,
More informationUniversity of Rome Tor Vergata
University of Rome Tor Vergata Faculty of Engineering Department of Industrial Engineering THERMODYNAMIC AND HEAT TRANSFER HEAT TRANSFER dr. G. Bovesecchi gianluigi.bovesecchi@gmail.com 06-7259-727 (7249)
More information(Heat capacity c is also called specific heat) this means that the heat capacity number c for water is 1 calorie/gram-k.
Lecture 23: Ideal Gas Law and The First Law of Thermodynamics 1 (REVIEW) Chapter 17: Heat Transfer Origin of the calorie unit A few hundred years ago when people were investigating heat and temperature
More informationCHAPTER 17: THERMOCHEMISTRY. Mrs. Brayfield
CHAPTER 17: THERMOCHEMISTRY Mrs. Brayfield REVIEW What is the law of conservation of energy? It states that energy cannot be created or destroyed So the energy of any process is the same THERMOCHEMISTRY
More informationLecture 6 Examples and Problems
Lecture 6 Examples and Problems Heat capacity of solids & liquids Thermal diffusion Thermal conductivity Irreversibility Hot Cold Random Walk and Particle Diffusion Counting and Probability Microstates
More informationRocket Propulsion Prof. K. Ramamurthi Department of Mechanical Engineering Indian Institute of Technology, Madras
Rocket Propulsion Prof. K. Ramamurthi Department of Mechanical Engineering Indian Institute of Technology, Madras Lecture 11 Area Ratio of Nozzles: Under Expansion and Over Expansion (Refer Slide Time:
More informationIntroduction to Heat and Mass Transfer
Introduction to Heat and Mass Transfer Week 16 Merry X mas! Happy New Year 2019! Final Exam When? Thursday, January 10th What time? 3:10-5 pm Where? 91203 What? Lecture materials from Week 1 to 16 (before
More informationEnergy and Energy Balances
Energy and Energy Balances help us account for the total energy required for a process to run Minimizing wasted energy is crucial in Energy, like mass, is. This is the Components of Total Energy energy
More informationLecture 9 Laminar Diffusion Flame Configurations
Lecture 9 Laminar Diffusion Flame Configurations 9.-1 Different Flame Geometries and Single Droplet Burning Solutions for the velocities and the mixture fraction fields for some typical laminar flame configurations.
More informationPhysics 115. Specific heats revisited Entropy. General Physics II. Session 13
Physics 115 General Physics II Session 13 Specific heats revisited Entropy R. J. Wilkes Email: phy115a@u.washington.edu Home page: http://courses.washington.edu/phy115a/ 4/22/14 Physics 115 1 Lecture Schedule
More informationThermochemistry. Using Heats of Reaction - Hess s Law - Standard Enthalpies of Formation - Fuels Foods, Commercial Fuels, and Rocket Fuels
Thermochemistry Understanding Heats of Reaction - Energy and Its Units - Heat of Reaction - Enthalpy and Enthalpy Change - Thermochemical Equations - Applying Stoichiometry to Heats of Reaction - Measuring
More informationFundamentals of Plasma Physics
Fundamentals of Plasma Physics Definition of Plasma: A gas with an ionized fraction (n i + + e ). Depending on density, E and B fields, there can be many regimes. Collisions and the Mean Free Path (mfp)
More informationThermochemistry. Energy. 1st Law of Thermodynamics. Enthalpy / Calorimetry. Enthalpy of Formation
THERMOCHEMISTRY Thermochemistry Energy 1st Law of Thermodynamics Enthalpy / Calorimetry Hess' Law Enthalpy of Formation The Nature of Energy Kinetic Energy and Potential Energy Kinetic energy is the energy
More informationIntroduction to Mass Transfer
Introduction to Mass Transfer Introduction Three fundamental transfer processes: i) Momentum transfer ii) iii) Heat transfer Mass transfer Mass transfer may occur in a gas mixture, a liquid solution or
More informationChapter 12. Temperature and Heat. continued
Chapter 12 Temperature and Heat continued 12.3 The Ideal Gas Law THE IDEAL GAS LAW The absolute pressure of an ideal gas is directly proportional to the Kelvin temperature and the number of moles (n) of
More informationConvective Mass Transfer
Convective Mass Transfer Definition of convective mass transfer: The transport of material between a boundary surface and a moving fluid or between two immiscible moving fluids separated by a mobile interface
More informationRocket Propulsion. Combustion chamber Throat Nozzle
Rocket Propulsion In the section about the rocket equation we explored some of the issues surrounding the performance of a whole rocket. What we didn t explore was the heart of the rocket, the motor. In
More information