Reynolds Number Effect on Regenerative Pump Performance in Low Reynolds Number Range

Abstract

The effect of Reynolds number on the performance of a regenerative pump was examined in a low Reynolds number range in experiment. The head of the regenerative pump increased at low flow rates and decreased at high flow rates as the Reynolds number decreased. The computation of the internal flow was made to clarify the cause of the Reynolds number effect. At low flow rates, the head is decreased with increasing the Reynolds number due to the decrease of the shear force exerted by the impeller caused by the increase of leakage and hence local flow rate. At higher flow rates, the head is increased with increasing the Reynolds number with decreased loss at the inlet and outlet as well as the decreased shear stress on the casing wall.

Study for the Increase of Micro Regenerative Pump Head

“…In the previous study, it was found that the pump head increased at low flow rates as the Reynolds number decreased [2] and the pump head increased by attaching vanes on both sides of the impeller due to the decrease of the leakage flow rate through the clearance between the impeller and the casing [3]. The pump head of the symmetric impeller with vanes on both sides was about 2.5 times as large as that of the asymmetric impeller with vanes on one side, but the pump head was about two third of our desired pump head.…”

Effects of the geometrical conditions on the performance of a side channel pump: A review

“…The variation of the Reynolds number plays an important role in the performance of the regenerative pump computationally and experimentally. It was established by Horiguchi et al that, as the Reynolds number declines, the pressure head of the regenerative pump rises at low flow rate and reduces at high flow rate. This effect of the Reynolds number is greatly affected by the degree of the shear force applied to the impeller and the shear stress exerted by the fluid on the casing wall.…”