Film building in circular EHL contact lubricated by oil droplet groups

Numerical calculations have been conducted to study elastohydrodynamic lubrication (EHL) with lubricant in the form of droplet groups, which was aimed to simulate air-oil lubrication. Two types of lubricant droplet distributions, ie, 1 row of droplets along the centreline of the contact or 2 rows of droplets on each side of the centreline, were adopted. The results showed that continuous EHL film could be obtained in spite that discontinuous lubricant droplets were supplied, which is attributed to the squeeze spread and rejoining of the droplets at the inlet. The total effective lubrication time for full film lubrication has a linear correlation with the number of the droplets, and there exists an optimum droplet spacing distance for continuous full film lubrication. For a constant volume of lubricant, calculations indicated that for most efficient lubrication, there is a trade-off between the droplet size and the number of droplets divided.