Pressure ripple reduction in positive displacement pumps: mathematical and experimental analysis

This thesis focuses on reducing pressure ripple in hydraulic systems, specifically those using positive displacement pumps like axial piston and external gear pumps. Pressure ripple, caused by pulsating flow from these pumps, leads to issues like noise, vibrations, and increased wear. The thesis investigates both passive and active methods to reduce pressure ripple. Passive methods include in-line gas bladder suppressors and quarter-wave resonators, while the active method involves a piezo-actuator-based system. The work includes mathematical modelling using the lumped parameter method and experimental validation to assess the effectiveness of these methods. The thesis concludes by presenting an optimized spring-piston accumulator-based system, ready for prototyping, to further reduce pressure ripple.