Visualization of pump internal flows using multi-color oil-film technique

摘要

A multi-color, oil-film flow visualization technique, featuring the use of a tri-primary, color fluorescent powder as a pigment, was proposed and applied for the flow visualization of pump internal flow fields. The flow patterns obtained by thetri-primary and intermediate colors were found to be useful in determining the interaction between various secondary flows, as well as the source of secondary flows. This new technique was used for a diffuser pump (specific speed : 280m{sup}3/min, m,min{sup}-1) to determine the impeller internal flow at different flow rates, typical flow patterns before and after occurrences of impeller inlet recirculation, and flow separation on the diffuser hub surface. Results obtained assured the adequacy andapplicability of this technique.