Hi all, I have recently been shown a diagram of pressure versus piston position for a particular heat engine. The system is based on a Joule cycle and is designed to take a drive stroke at constant pressure. Now what I'm trying to understand is, the pressure appears to 'wobble' slightly during the drive stroke, leading to a loss in efficiency. I understand that this is due to some kind of resonance occuring within the pipe, and could possibly be solved with pulsation dampers. Can anyone provide me with a better explanation of the phenomenon - is it well documented? - and ideally provide me with a few references for further reading. Many thanks.