CBE 30356 - Lecture Notes - March 7, 2023
Announcements
Class notes
Read through pages 214-229 of the notes and view the online narration below. Don't forget to complete the quiz in Canvas!
The main points of the lecture were
- The origin of the Stefan-Boltzmann Law
- Radiation transfer between parallel planes
- Combined radiative and convective heat transfer
Goals:
After this class you should be able to:
- Know how to add in radiation as a transport mechanism in an overall energy balance.
- Know how to calculate heat losses for non-gray bodies.
- Understand where global warming comes from...
Reading
- The class notes.
- BS&L, 16.1, 2, 3 & 5
Problem of the Day:
In class today we will look at arguably the most expensive radiation shield ever made: the tennis court sized
multilayer radiation shield for the Webb space telescope, and examine why it has its rather peculiar looking design. A description of the sunshield is provided here. A brief analysis of why it is designed the way it is is provided here.
Demonstration:
While diffusion is a very slow process it can be accelerated by convection induced by density gradients resulting from diffusion. In this demonstration we look at the visually appealing dissolution of a row of Skittles on a curved plate. As the Skittles dissolve in the hot water the higher density of the sugar laden water drives a gravitational current to the center of the plate. Lateral diffusion is so slow, however, that the colored streaks remain segregated, yielding the observed pattern.
David.T.Leighton.1@nd.edu