Knowledge, time and money (KTM). Sprinkle enough of it on your LSR project
including a measure to overcome demon randomness and you'll accomplish a
reasonable goal.
OK, Mayf pretty well outlines the big engineering problem that we all
instinctively know requires NASA (or at least Ford Motor Co.) levels of KTM
to solve. I think most of us prefer a simpler approach that provides useful
rules of thumb rather than a lot of heavy math. Greg Myers' anecdote about
the Wright brothers describes the way a lot of us operate. Singular
datapoints, experiences such as Kieth and Tom describe count for a lot, too.
Simple experiments like the swimming pool test Neil suggested. (Only a
Southland guy would suggest that this time of year) (Or are we maybe
suggstion a new Speedweek event for the motel swimming pools?)
Personally I like my idea of conning someone else into doing the work to
their own as well as our benefit. But if that fails? ...build a scale
moving surface wind tunnel. Will 1:25 scale produce useful results? There
are lots of cheap plastic car models in that scale. Or maybe larger scale?
(uh-oh!! KTM again....)
OK, let's see...here's things to go find:
1. 6" belt sander and some kind of variable speed motor to run it.
2. an electric leaf blower
3. A nice little linear bearing stage to mount the body on and transmit
aero forces to a spring scale with minimum friction drag
4. A way to accurately measure RPM's of the sander rollers and 5. below
(smells like "M"; more on that later)
5. Tiny can motors like the model train guys use in their locomotives to
turn the car wheels to match the belt travel speed.
6. K (knowledge) relative to building a small wind tunnel and application
of the scaling factors.
7. some kind of smoke generator?
8. Lots of cheap plywood
9. what else?
Ed Weldon
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