Numerical analysis of transverse reciprocating velocity effects in EHL point contacts

Experimental results by Fryza et al. [1] on the effect of transverse harmonic vibrations over the film thickness in EHL point contacts are directly compared here with numerical simulations assuming isothermal conditions and either Newtonian or Non-Newtonian fluid rheology. The simulations agree well with the experiments at the highest reciprocating speed frequency applied. It is then apparent from the comparison that with the oils and contact conditions analyzed, phenomena such as shear and thermal thinning, starvation and rig inertia have a minimal impact if not entirely absent. The simulated time-dependent film thickness fluctuations also show that, whereas the mean central film thickness decreases as reported by Fryza et al., both the global minimum and average film values increase as a result of adding a transverse reciprocating speed. Possible explanations for the obtained results are provided, highlighting the need for a broader analysis to better understand this type of problems.