I want gear that is completely necessary. What should I get?
Creating I put together a document describing the Free Control system version about 2 years ago and you can find it here:
This is an adiabatic expansion. It takes energy for a gas to expand into a vacuum, but no energy is allowed in from outside (insulating walls). Hence the air will cool. The amount of energy taken for a gas to expand into a vacuum is just PV, where V is the volume of the space (this follows from energy force x distance pressure x area x diatance). The total mass of gas involved is rho.V (rho density of air at atmospheric pressure), so with c as the specific heat you get c.rho.V.dT PV Or dT P/(c.rho) Calculatig the temperature chage is tricky because the specific heat, c, will not be the same throughout the process and cannot easily be derived because both P and V are changing. However, you can get an estimate of the temperature change by using cp for air. And note that the temperature drop does not depend on volume. You will find the result is surprisingly large - indeed adiabatic expansion is how gases are liquified.