Cheg 355 - Lecture Notes - Dec. 6, 2007
Announcements
The homework assigned today should be turned in to the TA 5pm on
on Thursday, Dec. 13.
Class notes
Scanned Notes
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
- Multi-Media Fluid Mechanics: Continue working through Boundary Layers: Separation.
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. A
nice discussion of the various effects is given
here.
Demonstration:
Homework Exercises (Turn in by 5pm, Dec. 13)
problem set 12
solution
David.T.Leighton.1@nd.edu