Design and Evaluation of a Closed-loop Test Facility for a Cryogenic Centrifugal Pump Using Liquid Nitrogen with High-Precision Performance Measurement and Flow Visualization Features

Abstract

We designed and developed a liquid nitrogen closed-loop test facility and a model centrifugal pump with an inducer of which there have been only a few examples. A notable feature of this test facility is its integrated structure connecting the pump motor to the rotating shaft of the pump. This allows for direct measurement of the torque generated by the rotating shaft and facilitates a more precise experimental evaluation of the test pump performance. In addition, this facility includes a visualization section for the inducer using a vacuum-insulated layer, which enables us to visualize cavitation in cryogenic fluids on the inducer blades. It is therefore possible to evaluate the impact of cavitation and its thermodynamic effects on the unsteady performance of the tested pump. Following the completion of the design and development of the test facility, we conducted the initial pump performance test to verify and evaluate each feature of this test facility for cryogenic pump experiments.