looking at where to start understanding how the thrust/lift generated by a specific propeller (hypothetical one) changes as a function of surrounding air pressure. obviously the lift will go to zero as air pressure decreases. as pressure increases, modelled by say mounting the propeller inside a sealed air chamber not much bigger in diameter than the propeller diameter and say 10 times the volume, how is lift effected and why? no specific calculation required, just trying to get my head around the physics. thanks any replies.