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View Full Version : Project 251A: calculating area of dynamic shapes


DaveC426913
Aug21-06, 07:54 PM
I don't even know how to phrase this, let alone which forum it should go in.

I'm trying to design a valve, like in a blood vessel. I want to ensure that the design "works" i.e. the shape of the valve will be determined by the volume of fluid moving through it. So, what shape will it take over time?

See attached really rough diagram of just a few steps. Two vessels are crossing at right angles and the valve (a very long, wavy, tentacle) is alternately letting red or blue fluid pass. It doesn't really have to make sense to you - I'm just trying to show you that, for example, the area of the contained fluid will have to remain constent once it's closed off, and that will affect the shape.

Note: this need only be designed in 2 dimensions. A 3D calculation is another ball of wax.

So: what tools do I use to get these shapes down, at least roughly? I'm currently using pencil and eraser to guess, but I can't calculate areas. Simulation software? Calculus? Analog simulation (marbles)?

Anybody want to take a crack at it?

0rthodontist
Aug21-06, 08:03 PM
I can't see the attachment yet. ImageJ
http://rsb.info.nih.gov/ij/
says it can measure the area of parts of a digital image, though I haven't tried it.

DaveC426913
Aug22-06, 01:53 PM
Ah! I got the mechanism, at least in rough. I am pleased.

Brainpower and a pencil beats s/w anyday...


Blue and red fluid cross each other but don't mix. Furthermore, they never really stop flowing (as they would with a simple "barn-door" design or a ball valve). Also, the valve mechanism (a waving cilia) is simple, tried and true.