Off-The-Shelf Variable Flow Rate Water-Propylene Glycol Hydraulics

A commercially available axial piston water hydraulic pump (Danfoss PAH 10) was evaluated under a range of pressures, speeds and fluid temperatures. Three candidate fluids were used in this evaluation: filtered tap water (as a baseline), a mixture of tap water and polypropylene glycol based antifreeze, and finally a mixture of synthetic seawater and polypropylene glycol based antifreeze. The effect of the fluids and temperatures on the pump efficiency was observed. The evaluation provides the basis for the design of a non-polluting variable flow water-antifreeze hydraulic power source.