抄録
In order to optimize the flow inside the pump, vane configurations of the impeller were verified. Through tracer particle based flow visualization, we have investigated flow patterns in term of the rate of particle crossover of impeller vane, its distribution to radial direction and residence time inside the pump. To create significantly different flow pattern three pump models of different vane configurations were fabricated. A newly developed visualization technique, the combination of a high-speed video camera based tracer method and an optical setup was applied for the measurement. Using a computer aided image measurement procedure;the loci of tracer particles were reconstructed from the visualized recorded images. In this study, these loci were investigated to estimate the magnitude and the duration of the imposed mechanical loading to the particle. Over an 800 ms observation, the rate of crossover was 19.9%in Type A, 12.6[%]in Type G, and 20.8[%]in Type I. Type A and Type I pumps showed the majority of crossovers occurring at the outer radius region, whereas Type G pump showed it at the mid-vane region. Regarding the residence time of the crossover particles, Type G showed the shortest residence time of41±7ms, while Type A was middle, 63±11ms, and Type I was the longest, 68±9ms. This fact confirms that the magnitude and the exposure time of mechanical loading varied with the variation of the impeller vane configuration.
