On Gas Lubrication in Turbulent Regime

Abstract

This paper analyzes first the transient conditions from laminar to turbulent regime for gas lubricated bearings. Then the pressure equation is deduced for self-acting gas-lubricated bearing by using Prandtl’s mixing length theory. A simple method for determining the pressure and the operating characteristics for bearings operating at high numbers H is given, based on an analogy with the corresponding laminar case. The pressure equation is also given for thrust and journal gas bearings under variable forces and velocities. The last two sections examine the influence of turbulence in externally pressurized gas bearings and the influence of inertia forces, respectively. The results obtained show that the turbulence does not alter qualitatively the operation conditions of gas-lubricated bearings. Moreover, the influence of turbulence in self-acting gas bearings is less important than in the case of liquid-film lubrication and even negligible when the bearing operates at high numbers H.