Mechanical Engineering Faculty Research


Experimental Flow Patterns and Pressure Characteristics in a Single Hydrostatic Pocket of Variable Depth

Document Type


Publication Date

Spring 3-1-2001


This article presents the results of an investigation into the flow patterns and pressure profiles that develop in a single pocket of a simulated hydrostatic bearing.The investigation has a dual purpose. The first is to determine the physics of the fluid patterns that develop under certain operating and geometry conditions; the second is to provide experimental information to the numerical practitioner for validation of numerical predictive and design codes.The flow was visualized in a hydrostatic pocket of variable depth.Two cases were considered: the first was that of a deep pocket (aspect ratio = depth/length = 1.0); the second was a shallow pocket with an aspect ratio of 0.25.The other parameters, which varied in the experiment, were shaft angular velocity and pocket feed–jet mass flow.The flow was mapped by means of a long-distance microscope combined with a particle trajectory visualization system; the illumination system was provided by a multikilohertz Nd:YLF pulsed laser. It was found that very different flow structures form, depending on the interplay among the strength of the feeding jet, the angular rotation of the shaft, and the aspect ratio of the pocket. It was also discovered that pressures grow continuously across the circumferential length of the pocket, in the direction of rotation.

Publication Title

Journal of Flow Visualization and Image Processing





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