How to Perform a Multi-Objective Design Optimization on Mixed-Flow Pumps?

High specific speed mixed-flow pumps, which are widely used at drainage pumping stations or power plants, often have performance curve instability characterized by positive slope in flow-head curve (stall characteristic) at low flow rate.

However, customers demand non-stall characteristics to operate the pumps in stable condition over a wide range of flow rate. Moreover, there are additional requests such as high efficiency from the viewpoint of energy saving in recent years and low shut-off shaft power and/or head to reduce motor capacities or flange sizes. The authors had been developing mixed-flow pumps to meet the demands, however we have learned that the characteristics (stall, efficiency and shut-off shaft power) are in relation of trade-offs. As a result, it is difficult to optimize these performance characteristics by conventional way such as trial and error approach by modifying geometrical parameters and so it is necessary to establish a new design approach.

Flow chart of the optimization designFig 1 - Flow chart of the optimization design.


As described in the paper, there are not so many reports about optimization design of pumps, much less multi-objective optimization about performance characteristics. The authors have been working on multi-objective optimization strategy of mixed-flow pump design by means of three-dimensional inverse design approach, CFD, DoE, response surface model and MOGA. Steady CFD is applied to leverage the approach on the actual design process.

This paper describes the multi-objective optimization approach for customizing performance characteristics of high specific speed mixed-flow pumps (Ns=1300). The objectives are pump efficiency, shut-off shaft power/head and instability characteristics. This strategy helps pump designers customize a new pump for specified flow-head characteristics in a short time.

 

Download the Publication

Mehrdad Zangeneh

Mehrdad Zangeneh is Founder and Managing Director of Advanced Design Technology and professor of Thermofluids at University College London.

View All Articles

MORE ON THIS TOPIC

Application of 3D Inverse Design Methods for Development of Centrifugal Pumps at Grundfos

Founded in Denmark in 1945, Grundfos now has an annual turnover of £2.6 billion and has an annual production of more than 16 million pump units,...

Online Event: Technology Day CASCON CFD Turbomachinery with ADT, CAFDEM & iSimQ

You're invited to a free online event on Wednesday, May 19 from 10:30 am – 12:00 pm to know more on the development of different type of pumps and...