Time-Resolved Particle Image Velocimetry (TRPIV) has been used to investigate the flow inside the suction chamber of an external gear pump where the movement of the fluid through the pump is maintained by the rotation of the gears. The main purpose of this paper is to study the characteristics of the complex flow pattern of this pump system in order to help in improving its total performance. The applied experimental techniques establish a method that allows visualising the flow inside the gear pump with a high rotational velocity system. Small micro air bubbles have been used as flow seeding. The images have been processed using domestic PIV software that uses specific aspects of the TRPIV technique. Instantaneous and phase-locked ensemble average fluid motions have been obtained for different gear pump rotational velocities to investigate the turbulence effect of rotating gears to the system.

Peer Reviewed