ON THE TRANSLATORY WHIRL MOTION OF A VERTICAL ROTOR IN PLAIN CYLINDRICAL GAS-DYNAMIC JOURNAL BEARINGS

Abstract

The determination of the bearing fluid film forces in a rotor system under dynamical conditions is discussed. In the case of a vertical rotor operating in a gaseous medium in plain cylindrical journal bearings, the steady whirl approximation is appropriate. In the steady whirl approximation, a set of rotating coordinates is employed, and the time dependence of the Reynolds equation is eliminated. At the same time, the compressibility number, Lambda, is replaced by the quantity (1-2 alpha/omega) multiplied by lambda. This approximation applies when both whirl acceleration and the radial velocity of the shaft are small. The attitude angle of the fluid film force is strongly dependent on the whirl motion. Experimental data of synchronous whirl agrees with the theoretical calculations based on the steady whirl analysis. A perfectly balanced vertical rotor in a plain gas dynamic journal bearing is always unstable with respect to the half frequency whirl.

Document Details

Document Type
Technical Report
Publication Date
May 08, 1961
Accession Number
AD0258425

Entities

People

  • B. Sternlicht
  • C.h.t. Pan

Organizations

  • General Electric

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Bearings
  • Compressive Properties
  • Equations
  • Experimental Data
  • Frequency
  • Journal Bearings
  • Motion
  • Physical Properties
  • Radial Velocity
  • Time Dependence

Fields of Study

  • Physics

Readers

  • Aerospace Engineering
  • Combustion and Flow Dynamics.
  • Structural Dynamics.