CBE 30355 - Lecture Notes - Dec. 5, 2023
Announcements
Class notes
Read through pages 304-315 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
Goals:
After this class you should be able to:
- Determine the characteristic length scale of the viscous sublayer in turbulent pipe flow.
- Estimate the magnitude of the eddy viscosity.
Reading
- The class notes.
- BS&L, chapter 5
Additional Readings:
An interesting example of boundary layer separation, turbulence, and angular
momentum is the design of a frisbee. Basically, the angular momentum produced by
the spin of the frisbee (and the weighted edges) keeps the frisbee stable (constant
orientation) while the aerodynamic lift produced by its motion relative to the air keeps
it up. Boundary layer control is important too: The ridges around the edge of the
frisbee promote turbulence and delay boundary layer separation, reducing drag. The
first frisbees tended to be unstable and didn't fly terribly well. It wasn't until the mid-60's
that the frisbee as we now know it was developed. The patent on the ridges can be found
here.
Demonstration:
David.T.Leighton.1@nd.edu