Pressure change when volume changes for incompressible fluid

[Chris F]

Homework Statement

Hi guys,

My first post here, I hope someone can help me out with a quick fluid mechanics problem.

I'm looking to calculate the pressure increase inside a closed tube full of water when the tube is crushed and therefore its volume reduced.

The tube is filled completely with water and pressurised to a nominal pressure of 10 bar. The starting volume is 2.1l and the volume after crushing is 90% of the initial volume.

2. The relevant equations

The tube remains sealed at all times so I think I can consider the fluid to be static and as its water, incompressible. However I am struggling to find the relevant equation to allow me to calculate the new pressure. All the static problems i have seen are concerned with open containers.

Can anyone help?

Thanks,

Chris

 

[Chestermiller]

Look up the BULK COMPRESSIBILITY of water. But a 10% decrease in volume seems very unlikely.

Chet

 

[Chris F]

Look up the BULK COMPRESSIBILITY of water. But a 10% decrease in volume seems very unlikely.

Chet

Ok thanks, so i can rearrange to solve for dP using the values i quoted above?

Sorry i should probably explained more thoroughly, I am crushing the tube with a press into a machined die as part of a hydroforming operation, the 10% is a rough approximation using the shape of the die as an indication of the form the tube will take.

Thanks,

Chris

 

[Chestermiller]

Ok thanks, so i can rearrange to solve for dP using the values i quoted above?Chris

yes.