Mohd Rody Mohamad Zin

A brief review on the wear mechanisms and interfaces of carbon based materials

Abstract The demand for reducing wear and friction has become the chief aim in the automotive industry nowadays. The usage of lubricant is not considered enough as there is still room for improvements. As a solution, much research has arisen towards what we called self-lubricating ideas, in order to reduce friction better than lubricant. This paper presents an overview wear mechanism and the interface of carbon-based materials. This paper will also discuss the interfaces by carbon as substrate and coating layer. The findings show that for metals, the predominant wear mechanisms were abrasion and fatigue. Meanwhile, for polymers and coating (DLC), they were abrasive along with adhesive wear. The surface roughness of the substrate plays a crucial role in increasing the excellent performance of the DLC coating. The interfaces of carbon elements definitely give huge impact on both self-lubricant materials and coatings where the coefficient of friction and wear rate changes drastically even with 1 wt.% addition. Nevertheless, a clear understanding of the factors that affect the tribological performance is very essential in performance improvement for potential applications.

Experimental Investigation on the Effect of Container Geometry Change to Liquid Sloshing

Liquid sloshing is any motion of free liquid surface inside its container. Sloshing may generate hydrodynamics loads that can be dangerous to structural integrity and stability of moving container. In this study, liquid sloshing in cubical and cylindrical containers with similar characteristic length were investigated. The containers with liquid inside were excited sinusoidally by using an electrodynamics shaker while the free liquid surface level change was captured by using high speed camera. The highest free liquid surface level difference obtained for cylindrical and cubical containers were compared. Results show that cylindrical containers produce less liquid sloshing and thus more suitable to be used for liquid transportation.

Accurate Numerical Prediction of Incompressible Fluid Flow in Lid-Driven Cavities

In this paper, we report an efficient numerical method to predict fluid flow behavior in a square and deep lid-driven cavities. The conventional continuity and momentum equations are transformed into stream-function and vorticity formulation to reduce the number of unknown spatial quantities. Numerical experiments were performed with different values of aspect ratio and Reynolds number to investigate the effect of these dimensionless parameters on the fluid flow behavior in the cavity. In the current study, we found that the dynamics and the structure of primary vortex are significantly affected by the Reynolds number and the aspect ratio of the cavity.