upward forces ?

[perrya]

I have a plastic container about 3" tall and about 1.4" in dia. It has a screw on cap. It is about 1/3 full of fluid. It is then "mixed" ... it is placed in a carrier and spun at about 3000 rpms (spun in a flat circular path). The fluid seems to take on a vortex like shape and rides up the inner wall of the container. I know that my CG is effected by the redistribution of the fulid during this process.

My question is ... is there a way to calculate the upward force created by this spinning fluid? Is it strictly a CG change/issue (the container sometimes will spin out of its containment carrier)? Or are there other forces that I am unaware of.

Thanks

 

[toys19]

Well i think the upward force is really due to the tendency of the fluid to want to move to the outside, if there is fluid in its way, it will push it out of the way - and that fluid is driven to the outside also so its resultant is up. To estimate the upward force consider 1 gram (or1/1000kg) of fluid (about 1cubic centimetre at 4degrees)C if this fluid is lifted 1 cm (1/100 m) to oppose gravity at approx 10m/s squred this requires 0.0001 of a newton. Please excuse my metric units and crummy physics.... hope this helps