An Experimental Study of Turbulent Flow in a Spiral-Groove Configuration

Abstract

Pressure and velocity data are reported for measurements in a large-scale experimental apparatus, designed to act as a model of a spiral-groove configuration operating at turbulent Reynolds numbers, and using air as a working fluid. The results predict that inertial effects at the steps in film thickness will exert a dominant influence on flows in machine elements made in geometric similitude to the model. Negative gage pressures were indicated in the thin-film regions, and these would be expected to lead at times to film breakup in elements using a liquid as the working fluid. Furthermore, negative stiffness under displacement of the journal was indicated for some operating conditions. The results, taken together, indicate the role of inertial effects, and dangerous operating conditions as to film breakup and loss of load support.