Will increasing the pressure of helium in a given volume increase the amount of weight it can lift?
Jamie:
The simple answer is – NO.
Now for the reason. Helium provides lift because it has a lower density than air. By increasing the pressure in the volume you increase the density of the gas contained in that volume.
From a lifting stand point the ideal pressure within the volume is exactly the same as the pressure outside that volume. The membrane that separates the inside and outside is just there as a separator.
If you look at this from another angle, helium filled balloons loose lift as they go up. The reason for this loss of lift is that the absolute pressure in the balloon remains more or less the same while the absolute pressure outside the balloon drops.
Yes, because balloons do stretch. So both pressures go down in absolute terms, but the pressure goes outside balloon goes down faster. As a result the relative density of the gas inside and outside the balloon change so that the balloon looses lift.
Niel
