Fill a small bottle with layered liquids

[cpxuvs]

Fill a small bottle with layered liquids, such as water and oil. This bottle will move slowly and irregularly in horizontal direction. What will happen to the stratified surface due to inertia? Is there any way to keep this stratified surface horizontal all the time?If possible, I hope that the inclination of the sloshing is less than 1 minute.

 

[anorlunda]

I think you may have an interesting question, but you're not explaining it very well.

The motion in a bottle is not perpetual. It must stop after a while unless driven by external forces.

I hope that the inclination of the sloshing is less than 1 minute.

Do you mean 1 minute of arc? 1/60 of a degree?

It sounds like you may be asking about a seich.
https://en.wikipedia.org/wiki/Seiche

Please try again to explain your question more clearly.

 

[cpxuvs]

I think you may have an interesting question, but you're not explaining it very well.

The motion in a bottle is not perpetual. It must stop after a while unless driven by external forces.
Do you mean 1 minute of arc? 1/60 of a degree?

It sounds like you may be asking about a seich.
https://en.wikipedia.org/wiki/Seiche

Please try again to explain your question more clearly.

Sorry，my English sucks.yes,I mean ，1 minute of arc.I have a device which has been doing plane motion and its height always slight changing (nonuniform polishing process).
For some reason, I need to find a horizontal plane on this device as the base level. So I thought of this way.I will appreciate it if you can give me any advice.If there is something you are not clear about, I will be happy to explain for you.

 

[cpxuvs]

The supplement of my question:A piece of wood floats on the surface of the water.Similarly,what happen when an object floats on the stratified surface of two liquids?

 

[anorlunda]

Moved to Mechanical Engineering. Hoping to attract an answer.

 

[anorlunda]

It is still unclear what you are asking, so I made a picture. You have two liquid media of different densities, so one floats on the other. You also have an non-uniform device floating on the surface between two media. You want to find a horizontal plane on this device. How do you define that? Is it the black line on this picture?

 

[256bits]

The supplement of my question:A piece of wood floats on the surface of the water.Similarly,what happen when an object floats on the stratified surface of two liquids?

here one also a an object floating at the interface between two fluids - air and water.
The wood motion can depend upon the motion of the interface - goes without saying.

The interface can be motionless and calm, in which case the wood would rest also calmly, and one could draw a horizontal line on the wood signifying the unchanging interface.
If the interface has movement, then the wood would be affected by that movement.
The interface can exhibit a sloshing effect as indicated in post #2
if the wood length is a fraction of the wavelength then the wood would follow the surface, with its ups and downs, and inclinations.
If the wood is a multiple of the wavelength, then a damping effect could be possible, so that the movement of the wood is not as drastic as noted above.

Since you are considering using this technique for leveling, or height purposes for the polishing machine - nonuniform polishing process was mentioned which I do not know exactly what that means - the machine will set up at the interface a higher frequency of vibrations, or multiples, upon which the wood will react to in a manner.
That also I would think has to be considered as well as the movement of the machine in its conceivable to and fro movement.

for air and water one can notice the wave action, sloshing, and endless ripples at the air-water interface.
A boat will not react very strongly to the ripples, somewhat to the wave action, and definitely to the sloshing.
A bug, or a short stick on the surface will react to all three movements of the interface.

By all means, I could be all quite incorrect on my interpretation.
But does that describe somewhat your question, and does it help.

 

[cpxuvs]

if the wood length is a fraction of the wavelength then the wood would follow the surface, with its ups and downs, and inclinations.
If the wood is a multiple of the wavelength, then a damping effect could be possible, so that the movement of the wood is not as drastic as noted above.
for air and water one can notice the wave action, sloshing, and endless ripples at the air-water interface.
A boat will not react very strongly to the ripples, somewhat to the wave action, and definitely to the sloshing.
A bug, or a short stick on the surface will react to all three movements of the interface.

What you say is basically correct, do you know the mathematical equation that a relatively heavy object floating in the oil-water interface with some slight disturbance?
Thanks

 

[Dadface]

If I was doing this i would start by doing simple experiments. I would start by holding the bottle in my hand and moving it from side to side. I imagine lots of sloshing going on. After trying different things I would place the bottle on a (smooth) horizontal surface and slide it horizontally back and forth. I would try to observe the effects of varying things such as the speed of movement, the acceleration, the angle of the surface, the surface area between the liquids, the liquids themselves ( eg use different viscosity combinations ).

 

[256bits]

do you know the mathematical equation that a relatively heavy object floating in the oil-water interface with some slight disturbance

Not off hand. Sorry.

 

[anorlunda]

do you know the mathematical equation that a relatively heavy object floating in the oil-water interface with some slight disturbance?

Neglecting oscillation of the device, just the waves in the liquids, the equation was given in the Seiche article I linked in post #2.

That formula gives you the period. The amplitudes are variable, so there is no specific formula for that.

Edit: Also see https://en.wikipedia.org/wiki/Ship_motions about the six axis of rocking of the device itself, superimposed on top of the waves in the liquid. If you need a detailed simulation, it won't be simple.I still don't understand your objective. Are you polishing the device to make it uniform thickness? If so, there may be very different ways to accomplish that.