A modified theory for the flow mechanism in a regenerative flow pump

The regenerative flow pump (RFP) and regenerative flow compressor (RFC) are turbomachines capable of developing high pressure ratios in a single stage. They are also known by other names, such as peripheral, side channel, turbine, traction and vortex compressor/pump. Even though the efficiency of RFP/RFC is usually less than 50 per cent based on past design experience, they have found wide applications in automotive and aerospace fuel pumping, booster systems, water supply, agricultural industries, shipping and mining, chemical and food stuffs industries, and regulation of lubrication and filtering. RFCs have been proposed for use in hydrogen gas pipelines and as helium compressors for cryogenic applications in space vehicles. RFTs are used as accessory drives on aircraft and missiles. With the aim of improving the performance and efficiency of an RFP, this paper proposes an improved and modified theoretical model that can explain the change in the circulatory velocity caused by variation in channel area. All previous works concentrated on the fully developed flow region in the RFP and this work expands consideration to the developing region. Furthermore, in order to make the above-suggested model a closed problem, several loss models were assumed and the results of predictions were compared with experimental and CFD data.