HP Air Bottle Sizing Problem

Let me give you the guideline

When the tank is empty, it is full of air.

The volume of air required = volume of tank = 4.1 m³ (but then these are at different pressures (and not 10 bar) so convert the 10 bar volume to the volume at required pressure

Rest you calculate (it is simple) and smells of homework due to the scenarios.

Thanks for your reply :)

Can you explain a little bit more please. What formula can be applied ?

P1V1 = P2V2 ??

Air is compressed at 10 Bar so when it goes in tank it will expand and water will be pushed out.....Am i right ? So how can i calculate the required volume of air to blow a tank of volume 4.1 Cubic meter.

I need the volume of compressed air required to empty the tank.

You may start with the formula you mentioned and 10 times appox with 10% extra.

rameshk

There is a lot of difference between theoritical and practical.

The theoritical is already given in the first post and sorry- for homework not going to elaborate more. Rest for you to think over and solve. And it is easy as I said.

Practical - I don't know. As the air filles up, it will push out the air. Then at a stage (much earlier than you think, there will be a paraboloid of revolution- ie 3 dimensional parabola of water) Then from the tip, the jet of air will eject out and that will carry almost atomised water with it. When this will be able to clear the total water I don't know, but I guess the time at t→∞.

But that does not matter since at the end of that time you are having the tank full of air at the unstable pressure (air in at 10 bar, and air out at some pressure p, and of course you know p=?). So In practical circumstances at the end of the infinite time too, the volume of air is a bit difficult since the air comes in at 10 bar + expands at nozzle and that has different pressures throughut then eddies are formed at back (hence different pressures) thus there will be point to point pressure distribution, and then the pressure can be averaged over the total system boundary then volume can be found. And then you have to teke care of the orofice flow at the outlet (and repeat almost the exercise of the inflow)

But you never do this, since it is worth it to open the drain, let it drain out and then dip it in water.

Er, 4.19 Cubic meter at 10 Bar?

No the pressure will be less (exactly how much I don't know) since lot of bubbles will bubbling out drain port.

This isn't a homework problem, is it? The solving of homework problems is frowned upon in this forum.