Ertel—Grubin methods in elastohydrodynamic lubrication – a review

With the arrival of powerful computers and sophisticated numerical methods the calculation of film thickness and pressure fields in elastohydrodynamically lubricated (EHL) contacts is now a common task. Complete moving-roughness solutions are easily found in literature including thermal effects, non-Newtonian rheology, and mixed-lubrication. Therefore, the pioneering days of analytical and semi-analytical EHL solutions lead by Ertel, Grubin, Crook, and others might be perceived as unfit for modern problems. However, it is important to recognise that despite their apparent simplicity these solutions have provided engineers with substantial insight of the lubrication problem. The present paper reviews Ertel—Grubin methods and shows the potential they still have in providing engineers with physical understanding and practical solutions in modern lubrication problems, including friction, transient effects, roughness, minimum film thickness, and shear thinning. The review is, however, not exhaustive.