MWF 11:30-12:20: MEB 248
Th 10:30-11:20: MEB 103

Instructor: Prof. Chris Bretherton breth@atmos.washington.edu ATG 710, x5-7414 Office hours: MW 12:30-1:20, (after class) or by appointment.

Teaching Assistant: Rahul Mahajan rahulm@atmos.washington.edu ATG 622, x5-9134 Office hours Tu 3:30-4:20, Th 1:30-2:20.

Course Description (from UW course catalog)

But note: We won't discuss Cartesian tensors or singular perturbation theory in any depth, but we will do sound waves.

Prerequisites

Textbook

Course organization and schedule

The course will comprise lectures and lab/film/quiz section days. Because I have heavy meeting travel commitments this quarter, the schedule of lab/film/quiz section days will be somewhat irregular. Thus, I have made up a day-by-day schedule so you know what is happening when. This may be updated as term progresses, because I have not taught this class for over a decade and am guessing at how long it will take me to cover some of the material. For past and upcoming lectures, scanned lecture notes are linked to the corresponding date in the table below.

I will also not be present for my regularly scheduled office hours on:

• We 28 Sep
• We 12 Oct
• Mo 24 Oct
• We 26 Oct
• We 9 Nov
• Mo 28 Nov
• We 30 Nov

Please email or call me to arrange another meeting time if you need to talk to me outside office hours (or take pot luck and just drop by) .

Grading

• Homework (50%), posted to class web page and assigned on a quasi-weekly basis. Collaboration with your fellow students is encouraged, but everyone needs to write out the homework in their own words. Late homework (after 5pm on due date) accepted only by arrangement with TA or instructor. There will be a 25% penalty on late homeworks except for your first one.
• Midterm (20%), Thursday 10 Nov, 50 min., in-class, closed book, 1 double -sided sheet of notes.
• Final (30%), take-home, open book and note, handed out Friday 9 December, due in my mailbox (ATG410) or under my office door by 5 p.m. Thursday 15 December.

Homework and Exams

Matlab scripts

Evolution of steady inviscid constant-density swirling flow in a pipe with an upstream nondimensional radius 1, uniform along-pipe flow U=1 and a swirling velocity component V = S*r after the flow moves into a part of the pipe where the pipe radius narrows by 50%. The script swirl_demo_commands.m calls functions to make the plot and animations we saw in class. To use it, open a Matlab command window and cut and paste each piece of the script into the window to see the corresponding plot. Plots (see links for examples) include

• A panel showing the upstream material ring radius r1(r2) and the downstream solution u2(r2), v2(r2), p2(r2) as a function of downstream radius r2, derived from coupled ODEs based on conservation of mass, circulation, and Bernoulli, as well as radial force balance.
• Animation of upstream streamlines traced out by three fluid parcels at different radii as they advect downstream.
• Animation of a segment of an upstream vortex line advecting in the upstream flow, with circles indicating material points along this vortex line.
• Animation of downstream streamlines traced out by the same three fluid parcels after they have advected past the narrowing, showing the downstream high-velocity swirling jet along the pipe centerline.
• Animation of a segment of an downstream vortex 'line' (which is helical) advecting in the downstream flow, with circles indicating material points along this vortex line.
• Animation of the streamlines traced out by the three upstream fluid parcels at different radii as they advect through the narrowing. One can see the innermost parcel get accelerated into the swirling jet. Here is the final frame of this animation.
• Animation of a segment of an upstream vortex line gets advected into the narrowing, and the increased swirl and speed of the fluid tilts and stretches this vortex line into its downstream helical shape. Here is the final frame of this animation.

• plot_helix.m
• plot_stream.m
• plot_vortex.m
• hw5h_solve.m
• plot_parcel.m
• plot_tube.m
• ramp.m