As for the boundary conditions though, the P1 tube would be twice as long as P2 and yes, the P1 is at constant pressure with P2 as well.
I'm really interested in knowing whether the expansion of the heated moist air could lift the piston in P2 in any capacity.
Our system of interest has a duct on the left and a piston chamber on the right that make the shape of the letter T rotated 90º clockwise. The smaller tube on the left is abbreviated as P1 has an unspecified length while the piston chamber is P2. The air in P2 heats up and expands while the...