ISSN:
0036-8792
Source:
Emerald Fulltext Archive Database 1994-2005
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Purpose - The purpose of the present study is to provide the dynamic characteristics of long journal bearings lubricated with couple stress fluids. Design/methodology/approach - Based upon the micro-continuum theory generated by Stokes, the dynamic Reynolds-type equation governing the film pressure is derived to account for the couple stress effects resulting from the non-Newtonian behavior of complex fluids. By applying the linear stability theory to the non-linear equations of motion the journal rotor, the equilibrium positions and dynamic characteristics of the system are evaluated. Findings - As compared to the classical Newtonian model, the effects of couple stresses signify enhanced stiffness and damping coefficients (including KXX, KXY?, BXX and BXY) at moderate values of the steady eccentricity ratio. Totally, as the rotor center operates at an eccentricity ratio about ?s=0.71, long bearings lubricated with couple stress fluids under small disturbance results in a higher stability threshold speed than that of the Newtonian-lubricant case. Originality/value - These findings provide engineers useful information in designing journal-bearing systems.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1108/00368790510575950
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