Three-Dimensional Flow Field in Rocket Pump Inducers—Part 1: Measured Flow Field Inside the Rotating Blade Passage and at the Exit

Abstract

The measurement of the flow field within the rotating passages as well as three-dimensional characteristics of the exit flow of an inducer model is reported in this paper. The flow within the inducer is probed by means of rotating pitot probe and pressure transfer device and at the exit by means of three hot wires located in three coordinate directions. In a high solidity inducer (4 bladed), considerable boundary layer growth is observed from hub to mid radius, while the flow from mid radius to tip is found to be highly complex, due to interaction of pressure and suction surface boundary layers and the resulting radial inward flow. The flow losses and wall shear stress derived from these measurements are found to be considerably higher than the corresponding stationary channel. The radial velocities are found to be of the same order of magnitude as axial velocities. Considerable improvement in the flow field is observed when the number of blades is decreased from four to three.