Investigating External Gear Pump Efficiency at Very Low Speeds With Graphene Nanofluids

Experimental investigations are performed to assess the operational efficiency of external gear pumps under high-pressure conditions, with a specific focus on varying shaft rotation speeds. These analyses encompass a broad range of rotational velocities, spanning from conventional to remarkably low speeds, reaching a minimum threshold of 150 RPM. At such reduced speeds, both volumetric and torque losses rise significantly, posing notable challenges to pump performance. Additionally, the lubrication conditions at such modest velocities are often compromised, further constraining the operational range of gear pumps, and limiting the efficiency of pump-controlled systems reliant on speed modulation. The primary objective of the current investigations is to assess the potential effectiveness of nanofluids in enhancing pump performance, particularly under the demanding operational conditions delineated above. This entails scenarios where pump loads are very high, and operational speeds are diminished to reach markedly off-design operating conditions. Consequently, the study presents a comparative analysis of external gear pumps operating with a commercial fluid that is integrated with graphene nanoparticles. Performance metrics, in terms of volumetric and hydro-mechanical efficiency, are evaluated to assess the impact of the nanofluid on overall pump energy performance. The findings of this study provide a first insight into the influence of nanofluids on gear pump efficiency and offer data for pump modeling at low speed. Such analyses hold relevance when control of gear pumps through variable speed logic is needed, as they provide an understanding of the potential benefits and limitations associated with the adoption of nanofluid-enhanced pump systems.