Design optimisation of a regenerative pump using numerical and experimental techniques

Purpose - Regenerative pumps are the subject of increased interest in industry as these pumps are low-cost, low-specific speed, compact and able to deliver high heads with stable performance characteristics. However, these pumps have a low efficiency (35-50 per cent). The complex flow field within the pumps represents a considerable challenge to detailed mathematical modelling. Better understanding of the flow field would result in improvement of the pump efficiency. The purpose of this paper is to consider a numerical and experimental analysis of a regenerative pump to simulate the flow field and math pump performance. Design/methodology/approach - This paper outlines the use of a commercial computational fluid dynamics (CFD) code to simulate the flow field within the regenerative pump and compare the CFD results with new experimental data. A novel rapid manufacturing process is used to consider the effect of impeller geometry changes on the pump efficiency. Findings - The CFD results demonstrate that it is possible to represent the helical flow field for the pump which has only been witnessed in experimental flow visualisation until now. The CFD performance results also demonstrate reasonable agreement with the experimental tests. Research limitations/implications - The design optimisation only considers a number of blade geometry changes. The future work will consider a much broader spectrum of design modifications which have resulted in efficiency improvements in the past. Practical implications - The ability to use CFD modelling in conjunction with rapid manufacturing techniques has meant that more complex geometry configurations can now be assessed with better understanding of the flow field effects and resulting efficiency. Originality/value - This paper presents new flow field visualisation and better correlation to the matched performance than the current limited mathematical models. This paper also presents a novel method for rapid manufacturing of the pump impeller.