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.

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The leakage across the slipper land of a swashplate type axial piston pump is inherent in almost all the commercially available designs. This occurs due to the back flow of each piston through its orifice and gap between the slipper and swashplate. This flow phenomenon is studied in detail in the present work. To optimize pump performance with a reduced leakage, it is critical to know the fluid dynamics within the pump passages. In this paper, a three-dimensional CFD methodology has been created and employed to predict the pump performance in terms of pressure field, velocity vectors, and the flow pattern to understand pump flow. The methodology is established in the commercially available code ANSYS FLUENT 16.0 which supports the existence of complicated geometry in the form of narrow orifices and gaps between rotating and stationary walls. Slipper leakages, velocity and pressure fields are computed using simple algorithm approach at different designs and operating conditions. Experimental data of the film thickness is used in the present simulation. The effect of different piston pressure, slipper velocity, oil viscosity, slipper orifice diameter and slipper pool inner diameter is studied. Investigations of this kind may help for the development and design of slippers.

In the recent decades, the need for light weight and high specific strength has been the hot issue in many engineering field and also biomedical sectors. Magnesium and its alloys are considered as a light weight material due to its low density that can replaced aluminium, steel and titanium. However, at room temperature, magnesium alloys have closely packed hexagonal crystalline structure with restricted number of freely actuated independent slip system that suffers from poor ductility by 5%–8% approximately. Therefore, Magnesium alloy creates some challenges for the application of many industrial sectors. One technique that can improve strength properties without significant reduction of ductility is to add reinforcing nanoparticles within the magnesium matrix and making them an attractive choice for light weight structural application. The performance of magnesium matrix-based composites to a current stage depends upon the proper selection of composition and combination of reinforcement particles within the matrix materials. In light of the writing overview, the inclusion of reinforcing particles, for example, TiC, SiC, B4C, Al2O3, hybrid reinforcement and so forth is the way to betterment of the tribological behaviour and the mechanical properties of magnesium matrix composites. This paper presents a brief overview based on the available literature survey that the effect of different geometries and percentage contribution of reinforcement particles in various processing techniques on the mechanical properties, microstructure and wear behaviour of magnesium-based metal composites.