Similarity Rules, Flow Regimes, and Characteristic Relations
The hydrodynamic theory discussed in the previous chapter leads to the conclusion that with the conventional assumptions for laminar flow the characteristics in steady running of a journal bearing of specified design can be expressed non-dimensionally as functions of a single parameter -the duty parameter. ‘Specified design’ in this context does not imply geometric similarity. It requires, for a circular bearing, no more than geometrically similar boundaries of the bearing surface. For a non-circular bearing it is necessary to specify in addition some criterion defining proportionate circumferential variation of clearance; for example, the ellipticity ratio of an ‘elliptical’ bearing. The profile of the grooves, and the numerical value of the clearance ratio, do not enter into the specified design. The clearance ratio and the operating conditions are covered by the duty parameter.
KeywordsReynolds Number Flow Regime Journal Bearing Flow Coefficient Taylor Number
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