Application of nanofluids on various performance characteristics of hydrodynamic journal bearing—A review

Bearings are designed to support the loads normally applied to the shaft, while allowing relative movement between two machine elements. Journal or sliding bearings are perhaps the most well-known sorts of hydrodynamic bearings. The journal bearings contain no rolling elements and these bearings’ design and construction are simple, but their operation and theory are complex. Due to this and other advantages, journal bearings are much preferred in engineering applications. Simultaneously, the associated research and development have resulted in reasonable progress and therefore, a thorough review of these is earnestly felt. The static and dynamic characteristics of hydrodynamic journal bearings mainly depend on the lubricant viscosity and other factors such as load, speed, friction, and eccentricity. The review analysis focused on nanofluid lubricated hydrodynamic journal bearings are one of the rare topics of interest among tribologists. The use of a nanofluid as a lubricant is very important as it significantly improves the performance characteristics of the investigated bearing. The aggregation of nanoparticles in lubricants available commercially can cause a sharp increase in pressure drop and significantly improve the lubricant viscosity, which leads to an increase in load-carrying capacity. The tribological properties of various lubricants/base oils can be augmented by nanoparticles containing the lubricant. Studies have shown that compared to other conventional engine oils the load-carrying capacity is increased with nanoparticles containing the lubricant.