Subject: What formulas can I use to calculate the forces on a paddle in water?

Hi,
 In 1994 Karl Sims developed a process to evolve virtual creatures in a 
computer simulation. (see 
http://www.biota.org/ksims/blockies for additional info)

After discovering his research, I became intrigued with the 
possibility of creating an adaptation of these creatures' evolution on my home 
computer. At this point I believe that I have worked out methods for everything 
except the creatures' interaction with their world.

Since I want to recreate the underwater swimming version of his "blockies", 
I'll need to be able to calculate the forces resulting from passing various 
rectangular prisms through an uniform, noncompressible fluid. 

The dimensions of these blocks will range from cubes to paddles and bars, 
randomly. This has stumped me. All I need is a single vector result for 
each block, which I'll combine from every block in the creature to calculate 
the creatures' flex and motion.

In order to try to simplify the calculations, I've decided to only connect 
adjacent blocks at their corners, so the blocks will also only rotate around a 
corner, in any combination of its three axes.

If you can either provide a set of "computer friendly" formulas -- I'll be 
programming using Python, an object oriented language, sigmas for example are 
not "computer friendly -- or resources where I'll be able to glean the info I 
need I'd be amazingly happy  :)

Thanks for any help you can provide.

-Mike

Re: What formulas can I use to calculate the forces on a paddle in water?