Random Asides

another day, another math error

I think deciding on post titles must be the second-hardest thing about blogging. First-hardest, of course, would be remembering to blog in the first place.

My fluid dynamics homework is basically math this two-weeks. Fortunately we don’t have homework every week for this class, or I’d never get it done. I’d say I’ve done about 10 hours of work on this set so far. Probably 8 hours of that was in the wrong direction. I spent a couple hours today trying to figure out why my answer to a differential equation was impossible boundary conditions. It’s because it was a 3D instead of 2D problem. Kinda hard to tell when it’s written U(x,y,-h,t) in one place, and U(x,y-h,t) in the other place. Which one is the mistake? Obviously not the one I picked first.

This class is kinda cool though. It’s a lot of work, and a lot of math, since most of the problems for the class have been generalizing an example in 2D to 3D. (But the professor doesn’t tell you that, nooooo. I just have a bit of pattern recognition) So far there have been 2 or 3 totally new (to me) methods of solving fluid mechanics problems.

One is similarity solutions, which is cool, because it reduces the number of variables your working with.

The other so far is perturbation analysis. I’m not sure if that’s cool or not, since I’m only partway through it. It seems to involve lots of imaginary numbers. Doing the 1st order part of it is ok.

Overall I think this class is a good class. It requires a lot more effort than I’m used to putting into the homework. And there’s no way I would learn this stuff without the homework, since it’s a familiarity thing. I can follow the instructions the first time through, but feel confused the whole time. However, I’m sure the second time (probably on the test) it will be less confusing.

The homework’s been on my mind and been taking the time and energy I’d use to write for skepchick. But! it’s almost done. Go me!


Related Articles


  1. Go you! Perturbation analysis was about the point where my maths degree started to go way over my head. Imaginary numbers are cool, unless they’re involved in partial differential equations, then they just make things worse.

  2. Frell me, I hated math. I could never get it to “work” for me. I would plug values into simple quadratic formulae, and get different answers every time. Had it not been for symbolic logic, I would never have gotten through University.

    It really bothers me, cos I love science. But if one isn’t fluent in math, it’s a very difficult subject to appreciate fully. Let alone to make a living at it– especially physics-heavy branches of science.


  3. Ooh, I’m having a flashback!

    I worked a lot of diff-q equations in cylindrical coordinates, which translated well in the fluid dynamics work. My math professor lived in between the two professors who taught second year thermo and the fluid/mass/heat transfer dynamics, so he frequently would assign math problems that would tie to the fluid flow in cylindrical coordinates concepts.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Back to top button