Integrated Thermal-Structural Analysis and Material Optimization of a Compression Ignition Engine Exhaust Valve Using Finite Element Simulation

Abstract

This study presents an integrated thermal and structural analysis of a compression ignition engine exhaust valve to enhance its performance, durability, and thermal efficiency under severe operating conditions. The exhaust valve operates under high combustion temperatures and fluctuating mechanical loads, requiring careful optimization of both material properties and geometry. A three-dimensional valve model was developed in SolidWorks and analyzed in ANSYS Workbench 16.2 under steady-state thermal and static structural conditions. Five materials, stainless steel, structural steel, carbon steel, martensitic steel, and nickel-titanium, were evaluated based on heat-flux distribution, equivalent stress, and deformation behavior. Results showed that structural steel achieved superior thermal performance with the highest total and directional heat flux, while nickel-titanium exhibited the lowest von Mises stress, indicating better mechanical resilience. Analysis of fillet radius variation further revealed that a 37.4 mm fillet provided an optimal balance between heat dissipation and stress reduction. The proposed thermo-structural approach establishes reliable design recommendations for exhaust valves, contributing to improved efficiency and extended service life of compression ignition engines. This study bridges the gap between independent thermal and structural analyses by combining both within a single ANSYS-based framework to assess material and geometric optimization for CI engine exhaust valves.