... viscosity or increasing piston/bore gap, the energy lost to fluid shear was minimized. This resulted in improved energy recapture via the regenerative membrane. Various piston masses and materials were also considered. Decreasing piston mass reduced piston stroke length and increased frequency of operation...

... mechanical stability power transmission (mechanical) sliding friction viscosity This paper is an extension of our recent work ( 1 ) in which we proposed a 12 - degree -of-freedom (DOF), linear time-varying (LTV) analytical model for helical gears that characterizes the contact plane...