Loading...

ME204: Heat Transfer

Unit 5: Radiation   In this unit, we will study the third mode of heat transfer: radiation.  Unlike conduction (Unit 2) and convection (Unit 3), thermal radiation does not require matter to act as its medium of transference.  In this unit, we will first look at the basic terminology and fundamental equations of radiation.  You will first be introduced to blackbody radiation heat transfer and then move onto how to calculate exchange of radiative energy between two surfaces.

Unit 5 Time Advisory
This unit will take you approximately 20 hours to complete.

☐    Subunit 5.1: 2 hours

☐    Subunit 5.2: 4 hours

☐    Video Lecture: 1 hour

☐    Reading: 3 hours

☐    Subunit 5.3: 4 hours

☐    Video Lecture: 1 hour

☐    Reading: 3 hours

☐    Subunit 5.4: 4 hours

☐    Video Lecture: 1 hour

☐    Reading: 3 hours

☐    Subunit 5.5: 6 hours

☐    Video Lecture: 1 hour

☐    Reading: 5 hours

Unit5 Learning Outcomes
Upon successful completion of this unit, the student will be able to: - Calculate radiation heat transfer between surfaces and their enclosures. - Define radiation properties of materials. - Explain the mechanisms underlying solar radiation. - Calculate heat transfer with combined conduction, convection and radiation. - Explain Kirchhoff’s Law. - Calculate radiation heat transfer between two gray bodies.

5.1 Fundamentals of Radiation   - Reading: Infrared Imaging Experiments’ “Conduction, Convection and Radiation from A Light Bulb” Link: Infrared Imaging Experiments’ “Conduction, Convection and Radiation from A Light Bulb” (YouTube)
 
Instructions: Please click on the above link, which will take you to a webpage of heat transfer experiments captured by Infrared video.  Browse to the sections titled “Conduction, Convection and Radiation from A Light Bulb”.  Read the descriptions and watch the video.  Click on the link “Read more” if you are interested in a more detailed description of the experiment.  Feel free to watch other experiments on the website.

 Terms of Use: Please respect the copyright and terms of use
displayed on the webpage above.
  • Reading: MIT: Professors John Lienhard IV and John Lienhard V’s A Heat Transfer Textbook: “Chapter 10: Radiative Heat Transfer” Link: MIT: Professors John Lienhard IV and John Lienhard V’s A Heat Transfer Textbook: “Chapter 10: Radiative Heat Transfer (PDF)

    Instructions: For this unit, please read sections 10.1-10.4 of “Chapter 10: Radiative Heat Transfer” (pp. 527-565), which will introduce you to basic concepts and governing equations of thermal radiation.  The reading will cover the material that you need to know for subunits 5.1-5.6. 

    You should start by reviewing section 1.3, pages 27-32, to make sure that you know all the key ideas of radiation (e.g. blackbody, electromagnetism, absorbance). 

    Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

  • Lecture: YouTube: Indian Institute of Technology (IIT) Bombay: Professor S.P.Sukhatme and Professor U.N.Gaitonde’s “Lecture 10: Thermal Radiation,” “Lecture 11: Thermal Radiation-2,” “Lecture 12: Thermal Radiation-3,” “Lecture 13: Thermal Radiation-4,” “Lecture 14: Thermal Radiation-5,” and “Lecture 15: Thermal Radiation-6”

    Link: YouTube: Indian Institute of Technology (IIT) Bombay: Professor S.P.Sukhatme and Professor U.N.Gaitonde’s “Lecture 10: Thermal Radiation,” “Lecture 11: Thermal Radiation-2,” “Lecture 12: Thermal Radiation-3,” “Lecture 13: Thermal Radiation-4,” “Lecture 14: Thermal Radiation-5,” and “Lecture 15: Thermal Radiation-6”  (YouTube)

     

    Instructions: Please watch these videos (about 55-56 minutes for each lecture), which will introduce you to the basic concepts of radiation heat transfer.  This video will cover the material that you need to know for subunits 5.1-5.6.

     

    Terms of Use: Please respect the copyright and terms of use displayed on the webpage above

5.1.1 Emittance   Note: This topic is covered by the resources below subunit 5.1.  Read pages 529-532 of section 10.1 of the Lienhard-Lienhard textbook.

5.1.2 Intensity of Radiation   Note: This topic is covered by the resources below subunit 5.1.  Read pages 532-535 of section 10.1 of the Lienhard-Lienhard textbook.

5.2 Kirchhoff's Law   - Reading: MIT: Professors John Lienhard IV and John Lienhard V’s A Heat Transfer Textbook: “Chapter 10: Radiative Heat Transfer” Link: MIT: Professors John Lienhard IV and John Lienhard V’s A Heat Transfer Textbook: “Chapter 10: Radiative Heat Transfer” (PDF)
 
Instructions: For this unit, please read section 10.2 of “Chapter 10: Radiative Heat Transfer,” which will introduce you to Kirchhoff’s Law.  The law states that at thermodynamic equilibrium, a body emits as much energy as it absorbs from each direction and at each wavelength.  Make sure that you understand the gray body approximation on page 538.

 Terms of Use: Please respect the copyright and terms of use
displayed on the webpage above.

5.3 Radiation Exchange between Two Finite Black Bodies   - Reading: MIT: Professors John Lienhard IV and John Lienhard V’s A Heat Transfer Textbook: “Chapter 10: Radiative Heat Transfer” Link: MIT: Professors John Lienhard IV and John Lienhard V’s A Heat Transfer Textbook: “Chapter 10: Radiative Heat Transfer” (PDF)
 
Instructions: For this unit, please read section 10.3 of “Chapter 10: Radiative Heat Transfer” (pp. 527-565).  You will learn about how to calculate radiation heat exchange between two finite black bodies.  Make sure that you can explain view factor reciprotiy (pp 540-541).  Work through examples 10.1.

 Terms of Use: Please respect the copyright and terms of use
displayed on the webpage above.

5.3.1 Calculation of View Factor   Note: This topic is covered by the resources below subunit 5.3.  Read pages 542-550 of section 10.3 of the Lienhard-Lienhard textbook.  Make sure that you understand table 10.2 on page 545, which will allow you to calculate the view factor for a number of two-dimensional configurations.

5.4 Radiation Exchange between Two Gray Bodies   - Reading: MIT: Professors John Lienhard IV and John Lienhard V’s A Heat Transfer Textbook: “Chapter 10: Radiative Heat Transfer” Link: MIT: Professors John Lienhard IV and John Lienhard V’s A Heat Transfer Textbook: “Chapter 10: Radiative Heat Transfer”(PDF)
 
Instructions: For this unit, please read section 10.4 of “Chapter 10: Radiative Heat Transfer” (pp. 527-565).  You will learn about how to calculate radiation heat exchange between gray bodies.  Make sure that you can define irradiance and radiosity, then explain the analogy between Ohm’s law for electricity and radiation exchange between two gray bodies.  Work through Example 10.5 on page 553.

 Terms of Use: Please respect the copyright and terms of use
displayed on the webpage above.

5.5 Solar Radiation   - Assessment: The Saylor Foundation's “Unit 5 Assessment” Link: The Saylor Foundation's “Unit 5 Assessment (PDF)
 
Instructions: Please complete the linked quiz.  When you are done, check your work against The Saylor Foundation's “Unit 5 Assessment Answer Key (PDF)

  • Reading: MIT: Professors John Lienhard IV and John Lienhard V’s A Heat Transfer Textbook: “Chapter 10: Radiative Heat Transfer” Link: MIT: Professors John Lienhard IV and John Lienhard V’s A Heat Transfer Textbook: “Chapter 10: Radiative Heat Transfer” (PDF)
     
    Instructions: For this unit, please read section 10.6  of “Chapter 10: Radiative Heat Transfer.”

    Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.