Abstract
A wall flow trace method using micro particles has been established in order to visualize leak flow through a narrow gap between impeller and casing wall of a miniature Magnetically Suspended Centrifugal Blood Pump. The size of the gap is so narrow that the oil film method cannot be easily applied to this flow.
In this method, CaCO 3 micro particles suspended freely in water form flow patterns on the impeller disk as a result of their adherance to the impeller's surface made of alminium. The results show that the flow patterns obtained by this method are clear enough to detect the flow direction, and also that the peripheral velocity of fluid near the inlet, in some cases, is faster than that of the impeller.
