Simulation Based Sensitivity Study of Piston Cooling Performance Parameters in Automotive Diesel Engines

Abstract

<div class="section abstract"><div class="htmlview paragraph">The increasing demand for higher power density in Internal Combustion Engines (ICE) leads to an engineering requirement for durable piston design and its cooling. To mitigate the likelihood of failure or damage to pistons, it is important to have a thorough understanding of the physics behind piston cooling along with the design and operating parameters that control piston cooling. Computational Fluid Dynamics (CFD) simulations provide an insightful way to evaluate the impact of different parameters that control piston cooling. This work pertains to diesel engines in particular and drives the sensitivity study of different piston cooling parameters such as oil gallery and Piston Cooling Nozzle (PCN) design features, engine oil and engine operating conditions. The analysis is conducted using a 3D CFD tool with multiphase modeling technique- Volume of Fluid (VOF) approach. Piston cooling parameters such as gallery oil filling ratio, capture efficiency and piston temperatures are used to assess and compare different simulation cases. The rise in oil temperatures inside gallery is also monitored.</div><div class="htmlview paragraph">Effect of a straight or oil gallery targeted PCN jet vs. inclined or off targeted PCN jet, PCN oil jet flow rate and temperature variation, distance of oil gallery from the piston crown surface are some of the crucial factors affecting the piston cooling which are discussed in detail in this work.</div><div class="htmlview paragraph">This study serves as a directional guidance and an optimization tool to the designers and stakeholders to gauge the impact of different parameters on piston performance and thus achieve the final design faster leading to significant cost saving.</div></div>