Bird strike(s)

Jim Logajan wrote:
If I recall correctly, damage is roughly proportional to energy of
impact, not momentum. (Based on the theory of spring deflection, I
believe: Suppose the object (goose or large weight) strikes a
compression spring. The spring would compress to about the same amount
because the spring equation, E_spring = k_spring_constant *
X_deflection, shows the linear proportionality between energy and
compression.)

Oops! What I wrote here is wrong. The equation E = k*X is only true for a
rare breed of springs known as constant force springs[*]. For conventional
Hook's law springs (F = k*X), the equation is of course E = 0.5*k*X^2.

So if E_kinetic = 0.5*m*V^2 and E_spring = 0.5*k*X^2, and the two energies
are set equal, after a little algebra the deflection is found:

X = V*sqrt(m/k)

So by the spring theory, damage WOULD be linearly propotional to the speed
while proportional to the square root of the mass - i.e. doesn't rise as
fast. Given the earlier example:

X_goose = 120*sqrt(14/k) ~= 449 * sqrt(1/k)
X_wt = 15*sqrt(1000/k) ~= 474 * sqrt(1/k)

Hmmm - interesting that they are still comparable with this selection of
weights and speeds!
[*] A spring loaded measuring tape is the most commonly known household
example of an item that has a constant-force spring in it. The restoring
force is the same no matter how far you pull the tape out.

You'd think the birds would learn to look out for you!

AJ

"Jim Logajan" wrote in message
.. .
So by the spring theory, damage WOULD be linearly propotional to the speed
while proportional to the square root of the mass - i.e. doesn't rise as
fast. Given the earlier example:

X_goose = 120*sqrt(14/k) ~= 449 * sqrt(1/k)
X_wt = 15*sqrt(1000/k) ~= 474 * sqrt(1/k)

Hmmm - interesting that they are still comparable with this selection of
weights and speeds!

The new numbers are just the square roots of double the old numbers, so
they're pretty much guaranteed to still be comparable. :-)

--Gary

Well..... watch for them, ours just left Thursday, about 10 PM, last
seen heading 225, 25 knts and climbing......

And the local dogs have learned to leave them alone... the hard way..


Dave

On Mon, 07 Nov 2005 21:53:09 GMT, "sfb" wrote:

Right, there are guys with dogs that given permission of the state will
harass the geese until they leave. Shooting at the geese doesn't do it.

"Newps" wrote in message
...
That's how we got rid of the Canada Geese at one of our small airports
near here. You get permission from your state, which ours readily
gave, then you harass the hell out of them. You kill some, you bother
the rest. Took a couple of weeks and haven't seen them since.



sfb wrote:

What idea? I've seen Canadian Geese get knocked off their feet by a
golf ball, roll-over, get up, and continue to eat and crap.

"Newps" wrote in message

Start shooting. They'll get the idea.

Anyone ever hit a bird? Anyone got a good bird avoidance plan they'd care
to share?

I've noticed most of the larger birds tend to tuck their wings and dive
when startled...

Also, we had a guy in our hangar take a small songbird-type right into
one of the air inlets of his RV-4... he spent a week cleaning bird guts
from between the cylinder fins. We ended up putting a bird silhouette
under the canopy.

Jim Burns wrote:
I caught the end of another Hannibal movie last night that I didn't even
know existed, Red Dragon. Now I'll have to rent it so I can watch the first
3/4 of it. It ended like it was a pre-courser to Silence of the Lambs.

Theres two flavors of that one out:

Manhunter (1986)
http://imdb.com/title/tt0091474

Red Dragon (2002)
http://imdb.com/title/tt0289765