Hydraulic press and compressible fluids

[tjrscurieux]

Hi everyone,
I did not get a reply in 3 weeks under mechanical engineeting... trying here.

Here is practical question mixing compressible and none compressible fluids with a hydraulic press. Can the following actually work ? I believe it can but some experience people in this field looking at it may prove me wrong.

Say we have a sphere, 1 cubic meter in volume. The sphere contains 0.5 cubic meter of water and the rest is pressurized air at 10 kg per square cm. There is a tube at the bottom of the sphere, 0.01 meter square. The tube is fill with water and linking the sphere to second part of the hydraulic press which is 0.1 meter square with a weight of 10 kg on it. Now the press cannot lower than the top of the tube and not higher then another 0.1 meter (thus 0.1 cubic meter of water). There is valve between the sphere and the second part of the hydraulic press. Initially the valve is in the close position.

Once the valve is put in the open position, will the press go up 10 cm ?

Now, the air is compressed to 10 kg per square and the tube is 0.01 m square so the hydraulic press with the area of 0.1 m square should be able to lift 100 kg. Since the compress air expands to fill 0.1 cubic m, we take the final pressure from 10 kg per square cm at 0.5 cubic meter to about 8 kg per square cm when we reach 0.6 cubic meter ( 20% less which is equivalent to the increase in volume of the air). So we can lift up to 80 kg on the press. Is this correct ?

If I am correct, someone know which formula can

 

[Valerie Park]

i use to calculate the lift of the press in this case ? It is a complicated issue, as it involves compressible and non-compressible fluids, but it is possible that the press can lift up to 10 cm. To accurately calculate the lift of the press, you would need to use Bernoulli's equation. This equation states that the total energy of a fluid stream is equal to the sum of pressure energy, kinetic energy, and potential energy. In this case, the pressure energy of the compressed air in the sphere and the potential energy due to the weight on the press can be used to calculate the lift of the press. The formula for the total energy is:E = P + ½ρV2 + mghwhere P is the pressure, ρ is the density of the fluid, V is the velocity, m is the mass, g is the acceleration due to gravity, and h is the height of the press. Using this equation, you can calculate the lift of the press.