Energy performance improvement for a mixed flow pump based on advanced inlet guide vanes

The sharp decrease in the efficiency of a mixed flow pump within over-load flow rates presents a challenge for coastal drainage pumping stations. To address this issue, two different structures of advanced inlet guide vanes (AIGV), full-adjustable (FA) and half-adjustable (HA) structures, are designed to approach a better energy performance improvement strategy. Entropy production theory is applied into transient flow field to reveal their influence mechanism on the spatial distribution of energy dissipation. The primary findings are as follows: (1) AIGVs effectively solve the sharp decrease in the energy performance of mixed-flow pumps within the over-load flow rate range, broadening its efficient operation range. (2) The decrease in the axial velocity under the effect of AIGV explains the primary fluid physics of the increased efficiency. (3) The improvement in the match between the impeller inflow angle distribution and the impeller blades structure suppresses the generation and transmission of the flow separation on the pressure side, and reduce the near-wall energy dissipation. The novel HA-AIGV obtains a better flow control effect.