What happens to the pressure of some gas, air for example, that is in a container almost full of liquid, some hydraulic fluid for example, when the liquid is pressurized?
The air is at 0 PSIG at the beginning, the container is rigid, a pump is connected to its bottom.
This is what I think: after the pump pressurize the hydraulic fluid, supposedly incompressible, the liquid now has an increased overall pressure that exerts to all directions. Since the air is compressible, it now has a smaller volume, and increased gage pressure that is equal of the increased overall liquid pressure. Is this correct?
If so, how does the new gage pressure of the air compare to the increased overall liquid pressure if there was no air at all in the container but full of liquid?