Study of the Thermal-Structural Behavior of a Piston Diesel With Gallery Through Finite Element Method

Abstract

The finite element analysis is a useful tool to investigate the behavior of a body subjected to different loads. The objective of this work was the analysis of an aluminum diesel piston provided with a cooling gallery, Cu-Zn bushings, and a Ni-resist insert. This piston is used in 1.9 L turbodiesel engines. The investigation was undertaken in order to observe the mechanical behavior of the piston at the operating temperatures and pressures and thus to study the performance of the different parts of the piston. The analysis was performed using a finite element software, taking into account a coupled field analysis and involving a fluid passing through the cooling gallery, temperature and pressure at the piston head which resulted in heat flow and thermo-mechanical stresses in the piston. According to the obtained results, it is worth noting the important role of Cu-Zn bushings in the piston as they support the highest stress of about 359 MPa and protect the piston against failure, and these bushings are able to support more stress that the body of the piston (aluminum yield stress limit 290 MPa). Also it is observed that the cooling gallery acts as a thermal barrier by preventing the heat flow from the head piston (approximately 213 ° C) toward the piston body (approximately 80 ° C). Another important aspect is the structural thermal interaction analysis and it can be observed the influence of high temperatures in the piston, increasing stress up to 100%. Finally it was concluded that the piston is able to withstand the operating pressures and temperatures.

Optimization of the Location of the Oil Cooling Gallery in the Diesel Engine Piston

“…So in the design process, it is very certainly necessary to calculate and analyze the piston temperature field, and to take effective measures to reduce the thermal stress in order to increase the ability to withstand the thermal load of the piston. Piston cooling technology is an effective method to solve these problems [2,3]. The purpose of using the cooling gallery is to reduce the temperature of the piston top surface [4] and piston ring groove portion (particularly the first and second groove), so that temperature of all critical position in the piston will be controlled in a reasonable limits [5].…”