Design Optimisation of A Centrifugal Pump For Augmented Performance

Abstract

Centrifugal pumps are one of the most popular turbomachinery handling incompressible newlinefluids in both commercial and domestic applications. The flow randomness newlineand flow instabilities while working at off-design conditions affect the useful operating newlinerange, functionality and efficiency of the centrifugal pump. Flow randomness such as newlineflow separation, recirculation, pressure fluctuations and flow inconsistency has adverse newlineeffect on the operation of the centrifugal pump. Researchers have recommended newlineto operate the centrifugal pump at or near the Best Efficiency Point (BEP). Flow newlineinstabilities at off-design conditions can be minimized through simple modifications in newlineconventional centrifugal pump, which may restore the operation near the best efficiency newlinepoint through minimization of hydraulic losses and through improvement in flow newlinepattern. Flow randomness near the suction region or eye of impeller is minimized newlinethrough modification of a conventional fastener of a centrifugal pump in the form newlineof nose cap of optimized profile. Considering geometric and design constraints 12 newlinenose caps of different lengths (50 mm to 80 mm) and tip angles (15o to 90o) are newlinedesigned. Experimental investigations are done on conventional pump to find the newlineboundary conditions for numerical analysis of a centrifugal pump. Numerical analysis newlineof centrifugal pump with nose caps is done using ANSYS FLUENT 17.0 at different newlineflow rates and results are compared in terms of performance parameters like head, newlineoverall efficiency and power consumption with a conventional low head mixed flow newlinecentrifugal pump. Numerical results are validated through experimentation at same newlineoperating conditions. Uncertainty analysis is carried out to count the experimentation newlineerrors. Numerical analysis shows overall efficiency improvement by 5.1% over newlineconventional centrifugal pump, whereas experimentation confirms improvement in newlineoverall efficiency by 3.94% for nose cap of minimum length and maximum tip angle. newlineNose cap with minimum length and maximum tip angle guides the suction fl