Hydraulic performance enhancement of a screw impeller-assisted axial flow pump: Experimental evaluation for Southeast Asian agricultural irrigation

This study is aimed to improve the performance of Phaya Nak axial-flow pump by modifying the design of the screw impeller. The test rig used was a ۳.۵ m long, ۵"- diameter axial-flow tube powered by an eight and a half HP, four-stroke gasoline engine. The three screw impeller designs were created in SolidWorks and compared to the impeller without any screw. The performance was tested at different operating conditions and water temperatures by observing the flow rate, pressure head, pump head, power consumption and hydraulic efficiency. The screw-assisted configurations obtained a maximum hydraulic efficiency of ۸۳% at the flow rate of ۰.۳ m³/s, and efficiency in the range of ۷۵–۸۰% was kept at lower flow rates. A ۴.۴% efficiency drop was observed with the increase in water temperature from ۲۵°C to ۳۵°C. The efficient axial-flow pump was also tested at a lower flow rate of ۰.۲ m³/s, and compared with centrifugal and propeller pumps, with an efficiency of ۸۰%. The study offers the design criteria for screw impeller geometry, shaft support and operating conditions in agricultural irrigation in Southeast Asia. This novelty is that three purpose-designed screw impellers have been systematically and experimentally tested, providing quantitative data on their efficiency, thermal derating coefficient and direct comparison with conventional pump types.

کلیدواژه ها:

Axial Flow Pump ، Screw Impeller ، hydraulic efficiency ، Pump Performance ، Agricultural Irrigation