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Re: Propellant fluid dynamics at zero-g

on 1/10/01 4:34 PM, Tony Langdon at tlangdon@atctraining.com.au wrote:

> Centrifugal force isn't a real force, but a "reaction force" caused by the
> inwards acceleration of the centripetal force.  Much like weight is caused
> by the reaction of the ground against our bodies which are being pulled into
> the Earth by gravity...

Well, correct, but it is also a reaction due to the  effects of Newton's
first law.

If we are riding in my car and I turn suddenly, we will "appear" to move or
feel like our bodies are moving in a direction opposite the turn.  Relative
to the car, we have moved, but relative to the world outside, we have not
initially moved.  Due to inertia, our bodies want to travel in the same
direction we were traveling in before the turn.  But the car has moved and
so we get pushed against the door or whatever.  This "force" continues until
the forces created by the car cause our own inertia to change (Newtons's
first law again) and things equilibrate.

In the extreme sense of continually driving in a circle, we will always feel
that movement to the outside since the car is in effect continually moving
away from the direction desired by our inertia which is tangential to the
circle of motion.  There is no force per se, that is pushing our bodies to
the outside, but rather it is an effect of our inertia.

The same applies to the fuel in the tanks.



Jon Ogden
NA9D (ex: KE9NA)



"A life lived in fear is a life half lived."

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