Aaron Froese

Mossy old maple tree in my parents' backyard

Tuesday, 06:44 am in Saskatoon

The use of COBOL cripples the mind; its teaching should, therefore, be regarded as a criminal offense. - Edsgar Dijkstra

Fourth Year

Reexamination of the Bathtub Vortex

Below are pictures of the apparatus I built for my Physics 409 lab to mimic the experiment done by a Danish group early last year. This is the final report, but I didn't have enough time in the semester to take enough data to learn anything new. I have compiled an amusing short video of some of my results. Be aware that it is 65 MB.

The frame and container (stepper controller on right edge of picture).
The piping to maintain constant water height
The chamber which spins to maintain the vortex. My food colouring and hypodermic injection system : ) are in the background.
The assembled apparatus...
...filled with water.
An interesting perspective shot of the drain.
I serendipitously noticed this very intriguing pattern coming from the inflow pipe.

Particle Simulation Project
Two-dimensional Elastic Collisions of Incompressible Spheres A paper I wrote to describe a phase of development of my Physics 410 term project.
Two-dimensional Solution This is a Maple worksheet which solves the problem much faster, although less elegantly. If you do not own Maple, I made an HTML copy.
Three-dimensional Solution When using Maple, it is a simple matter to extend the problem to three dimensions, although the answer isn't very pretty. There is an HTML copy for this one, as well.
Characteristics of a Two-Dimensional Gas Simulation The complete paper.

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Last modified June 07, 2006.