Ferrofluid Based Squeeze Film Lubrication between Rough Stepped Plates with Couple Stress Effect

This investigation purposes to study the magnetic fluid based squeeze film behavior on transversely rough stepped plates with the influence of couple stress. Using the well-known stochastic model of Christensen and Tonder the roughness effect has been evaluated. The magnetic fluid flow model of Neuringer - Roseinweig has been adopted to obtain the influence of magnetization. The governing Reynolds’ type equation is derived on the basis of stokes microcontinum theory for couple stress fluid. For the expression of pressure distribution, the stochastically averaged Reynolds’ type equation is solved. which results in calculation of load carrying capacity. The graphical outcomes also presented in tabular form suggest that although the bearing suffers on account of roughness, the magnetization and couple stress effect save the situation, as this combination does not allow the load carrying capacity to fall rapidly. However, in the case of negatively skewed roughness the magnetization goes a long way in dropping the adversarial influence of roughness by selecting an appropriate value of couple stress parameter when variance (-ve) is involved. It is found that the couple stress effect, alone may not be sufficient to counter the negative influence of transverse roughness and porosity. However, in almost all situations the ferrofluid lubrication adds significantly to the positive effect of couple stress to overcome the adversarial outcome of porosity and roughness. Further, the position of step plays a vital role for an all-round enhancement of the bearing performance.

Keywords:

Squeeze film , Stepped plates , Roughness , Couple stress , Ferrofluid , Load carrying capacity