Quote:
Originally Posted by TopSpin80
look up ANSYS and Fluent FEA... there are even FEA analysis' that show the flow rate/patterns of epoxy in a resing infusion.... I think the problem is there really is no way to completely and accurately do a planing hull... most is done for achieving laminar flow on a displacement hull such as a sailboat... what you are asking for is a combination of mostly airflow (aeronautics) and some hydrodynamics.
Ernie
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Thanks. I've long studied FEA for other uses, and am very aware of it's abilities and limitations (at least as of 5 years ago). I'm just trying to figure out what "engineering method" is being utilized here:
Yes, there's usually three ways things are done in the engineering world.
1. Complete computer predictions using actual accurate computer models. This can be done in SOME cases, but only if the theory is completely understood AND the input is good (hence "garbage in, garbage out). You'll often find the guys
in the laboratories griping over crappy computer models and all the work they have to do to actually "make it work" in the real world after the computer guys provided them with something unworkable. This was the state of IC engine design in the 80's and early 90's. It's much better now, and the computer guys work very closely with the lab rats.
2. SWAG: Scientific Wild Ass Guess - This is when you've got at least a partial understanding of what's going on so at least you continually know which direction to move in each iteration. Most of what you do is predictable, but often not the magnitude. Sometimes something surprises you, but when it does you take a step back and figure out why so that it doesn't happen again.
3. WAG: Wild Ass Guess - "We do it this way because it's the way we've always done it" or "It looked cool so we put it in and ran it. Doesn't seen to hurt anything". Most (but not all) "engineering" in the hot rod parts industry is done this way. They keep doing something till they find something cooler looking to copy.
I'm hoping bottom design at least falls into category number 2. From my experience with FEA I highly doubt they are to number 1 yet, but you never know. I'd at least be happy to see a book, article, white paper, or whatever that talks about the basic assumptions that go into high performance hull design.
