Cool Beaming Profile Video

[justinmreina]

Hey all,
Just rendered a beam profile video from 1kHz to 10kHz for a rectangular piston for my acoustics class, thought it was neat enough to perhaps share with you guys! In the video, the piston Y-Dimension is twice that of its X-dimension. Notice how that makes its beam pattern in that plane ~2 as dense.

Full Animation: http://justinreina.com/miscBin/BeamPattern.avi
*Youtube: http://www.youtube.com/watch?v=oURjsJQmgBw

Enjoy,
-Justin

[Pete Schumacher ®]

Hey all,
Just rendered a beam profile video from 1kHz to 10kHz for a rectangular piston for my acoustics class, thought it was neat enough to perhaps share with you guys! In the video, the piston Y-Dimension is twice that of its X-dimension. Notice how that makes its beam pattern in that plane ~2 as dense.

Full Animation: http://justinreina.com/miscBin/BeamPattern.avi

Enjoy,
-Justin

Can't get the video to play.

Got a location for a proper codec?

[dcibel]

Neat. I can't play this at work, but I'd imagine I can at home. This is for a flat rectangle? Can you make one for a 1" dome?

[justinmreina]

Shoot. Pete, I imagine you are using Vista or 7? I rendered this on an XP machine, so the codec is old (IV50; not supported in Vista or 7).

Hmmm, can't find a link to the IV50 codec

-Justin

[john trials]

I can't see the video either (using XP), but that picture is cool.

You have it easy (with computers). When I took acoustics in college (before PCs), I can recall using Bessel functions and polar coordinate graph paper to figure out this stuff in 2D...What a headache! I'm old enough to remember slide rules (I can't remember how to use one), but at least there were calculators by the time I took acoustics!

[mattk]

I can't see the video either (using XP), but that picture is cool.

You have it easy (with computers). When I took acoustics in college (before PCs), I can recall using Bessel functions and polar coordinate graph paper to figure out this stuff in 2D...What a headache! I'm old enough to remember slide rules (I can't remember how to use one), but at least there were calculators by the time I took acoustics!

In the spring of my senior year in high school I went to visit the college I ended up attending, which was an engineering only school, and I was really impressed by the large leather-holstered slide rules I saw some of the students with (yes, I am a geek). Much cooler than the 8" bamboo slipstick I used. A few weeks later TI came out with the SR50, which was the first affordable full trig calculator. That fall when I was a freshman there wasn't a slide rule in sight. Shortly after that HP came out with the 25c, which was their first affordable calculator, and sold T-shirts that said "Enter > =".

All our computer programs had to be written on keypunch machines, which were a big upgrade from the paper tape I used in high school, but I was very happy during my junior year when we got terminals. Then my first job used keypunch machines (albeit with dedicated keypunch operators) for the first few years I worked. Man am I old.

[Dirk]

Shoot. Pete, I imagine you are using Vista or 7? I rendered this on an XP machine, so the codec is old (IV50; not supported in Vista or 7).

Hmmm, can't find a link to the IV50 codec

-Justin

Try chucking it on youtube. See if they can convert it for you. Also gets you off the hook for hosting it.

[justinmreina]

Good call on youtube! http://www.youtube.com/watch?v=oURjsJQmgBw

I've never submitted to it before, I thought it was just for little girls to watch music videos...

The Good Old Days
I am just grateful I don't have to think about multi-dimensional concepts like you guys used to 'back in the day'. That must have been extreme pain. And don't worry, we still do the math these days, just no slide rules.

-Justin

[Zilch]

Not only beaming, it's also lobing.

Cool!

[Tell us why.... ]

[justinmreina]

Essentially the same deal right?

-Justin

[Zilch]

Nope, don't believe so.

Model a circular piston.

[Ask in class.... ]