Centrifugal Acceleration Gradient - 12/24/97
used in the
The following information is from the excellent book, 'The Third Industrial
Revolution' by G. Harry Stine.
Centrifuges can be used to produce acceleration gradients.
This is because the acceleration caused by the rotation of a centrifuge
depends on how far you are from the center of rotation.
On the end of the centrifuge arm or wheel, the acceleration caused by
centrifugal force is greatest.
As you move in toward the center of rotation, the acceleration becomes less
and less. In free-fall, you would be in a weightless condition at the center
of rotation. Thus, there is a difference of gradient in the acceleration.
A steeper gradient can be created by making the centrifuge smaller and
spinning it at a higher rate. Thus, for example, it would be possible to have
a space centrifuge with a normal, one-g, Earth-surface type of acceleration on
its end or rim while several feet inward toward the hub, the acceleration
could be half that amount.
Nobody has really given too much consideration to the fact that it is possible
to obtain acceleration gradients in space for industrial purposes. It's
not really possible to get an acceleration gradient from one-g down to zero-g
here on Earth because of the Earth's gravitational field.
So we haven't even developed or considered any industrial process
possibilities that might make profitable use of this unique potential of the
What can industrial engineers do with acceleration gradients made to order?
They could, for example, create a combined fractional distillation process
where solids of different densities are centrifuged out of the process at
different points in the distillation scheme.
It is very difficult to conceive of such future applications, however, because
we are still attuned to thinking of processes only in a one-g field here on
Earth. Once engineers get out into space and begin to live with these new
conditions on a daily basis, we will begin to see some totally unexpected new
The centrifuge principle, of course, can be used as a separation process in
space where there are no density-driven separation mechanisms.
Here on Earth, if you want to separate milk and cream, all you have to do is
let it sit for a time; the cream, being of less density, comes to the top
where you can skim it off for coffee or butter or ice cream.
You can do the job faster with a centrifuge that creates a higher acceleration
and a steeper acceleration gradient.
In the Orffyreus wheel, shifting weights move in towards the axle on the
ascending side and out to the rim on the descending side.
The idea is to produce an increased 'leverage' of the weight directed toward
the axle on the descending side and a decreased 'leverage' applied to the axle
on the ascending side.
Perhaps this acceleration gradient, centrifugally created is used to cause the
increases and decreases of leverage applied to the axle. Remember, this wheel
and all its internal components rest solely on the axle.