Re: Falcon first stage finished

Like moving a bucket of water in a circle, one
side of the bucket has the crest, the other side has the trough.

The average C.G. is still along the centerline of the vehicle, but the
instantaneous C.G. is moving in a circle with some radius R and the same
angular rate w as the engine gimbal's angular rate. If the angular
position of the gimbal is behind the angular position of the C.G., the
wave is flowing down hill and getting larger. The instantaneous C.G. shift
R will grow. If the angular position of the gimbal is ahead of the angular
position of the C.G. then the wave is trying to flow up hill, energy is
taken away and the instantaneous C.G. shift R will be reduced.


And then again, when moving a bucket of water around in a circle, a vortex
also form, making the instantaneous C.G. shift even worst. So moving the
gimbals in a circle in the opposite direction of the rotating C.G. is
probably much better. To get ride of the forming vortex. Chasing the
instantaneous C.G. around reinforces the vortex.

If the vortex reaches the inlet to the engine, whoosshhhh, out the Helium
goes. no pressure in the tank.

Or, add more baffles.

Just a guess.

--
Craig Fink
Courtesy E-Mail Welcome @ WeBeGood@xxxxxxxxx
.