4. Conclusions
In this work, a transient model is developed to simulate elastohydrodynamic behavior of a rotary lip seal containing undulations
and operating with a grooved shaft. This elasto-hydrodynamic analysis includes both thefluid mechanics of the lubricatingfilm
and the elastic deformation of the seal lip in isothermal conditions.
Numerical results show a better agreement to experiments
compared to the stationary model. This validates and proves the
importance of the proposed model. It is demonstrated that the lip
roughness amplitude is the most influencing parameter on sealing
mechanism. Indeed, it improves thefilm thickness that reduces
the friction effect and it also creates supplementary reverse
pumping.In addition, the present paper confirms the effect of the
grooved shaft on the rotary lip seal performance as simulated and
published previously. Thus, textured shafts with oblique grooves
can generate substantial pumping rates, from the air-side to the
liquid-side of the seal. This flow rises with groove density and
depth, but decreases with the groove angle. The friction torque
was also studied. It was proved that by considering a smooth lip,
the friction is overestimated compared to a rough lip case