Dynamic Characteristics of a Squeeze Film Damper Lubricated with Electro – Rheological Fluid in Terms of Reynolds Number
B. Rajneesh Kumar1, S. Ranganatha2

1Prof. B. Rajneesh Kumar, Department of Mechanical Engg., BMS Evening College of Engineering, Bangalore (Karnataka), India.
2Dr. S. Ranganatha, Department of Mechanical Engg., University Visvesvaraya College of Engineering, Bangalore (Karnataka), India.

Manuscript received on 21 September 2013 | Revised Manuscript received on 28 September 2013 | Manuscript published on 30 September 2013 | PP: 132-136 | Volume-2 Issue-4, September 2013 | Retrieval Number: D0813092413/2013©BEIESP
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© The Authors. Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open access article under the CC-BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Abstract: Smart fluid technology is an emerging field of research that leads to the introduction of Electro-rheological (ER) fluids. ER fluids are such smart materials whose rheological properties (viscosity, yield stress, shear modulus etc.) can be readily controlled upon external electric field. The use of ER fluids introduces a new philosophy on the fact that the stiffness and damping can be changed by applying high electric field and thus minimizing the vibration of the structure during normal operation. In the rotor vibration control of high speed engines squeeze film dampers are currently used. The dynamic characteristics (stiffness and damping) of a squeeze film damper lubricated with electro-rheological fluids are important in many practical engineering applications are studied for high accuracy and efficiency. The Reynolds equation of hydro-dynamic lubrication is normally used to determine the dynamic characteristics in the analysis of rotor dynamic system with squeeze film damper, which neglect the inertia effects. At high speeds both inertia and visco-elasticity introduce phase shifting effects into the fluid motion. As a result, prediction derived from Reynolds equation can be significantly in error. Here an improved expression is developed for the dynamic characteristic in terms of Reynolds’s number for a particular electro-rheological fluid. Bingham model has been used to describe the behavior of the electro-rheological fluids. The result leads to improvements and explain why it is significant to include fluid inertia forces which have large effects on dynamic characteristics.
Keywords: Dynamic Characteristics, Squeeze Film Damper, Electro Rheological Fluid, Reynolds Number.

Scope of the Article: Foundations Dynamics