Study on the performance characteristics and failure analysis of exhaust valves

Abstract

Abstract Exhaust valves are a type of valve that can commonly be found in the top section of the cylinder block in an engine. When failures occur on the exhaust valve, the engine has a high possibility to result engine failure or breakdown. This will affect the user where the user requires to spend a huge amount on repairing costs or engine replacement. Thus, this research aims to investigate the effect of the exhaust valve’s material on its performance and identify the appropriate material which could increase its fatigue life in a four-stroke internal combustion diesel engine. A three-dimension (3D) Computer-aided design model of the exhaust valve was generated by using SOLIDWORKS and undergo static structural analysis as well as thermal analysis. The measure variables are von-mises stress, total deformation, temperature, total heat flux and directional heat flux by using ANSYS Finite Element Analysis. Stainless steel 304 alloy and Aluminium-Silicon Carbide (Al-Sic) materials are the manipulated variable that was applied to the 3D CAD model exhaust valve to undergo all the analyses. Before performing all the analyses, the appropriate mesh method and mesh sizing was identified by referring to the mesh metrics spectrum and performing a mesh independence test. The results from the analysis were collected and tabulated for comparison and discussion purposes. From the analysis, the maximal thermal stress was determined in the valve stem region. By appointing Stainless Steel 304 alloy on the exhaust valve, the durability and the fatigue life are improved as the material can achieve a smaller value of temperature distribution, total heat flux, total deformation, and higher von-mises stress. This research provided a better understanding of the effect of an exhaust valve material on its performance characteristic.