Effect of Fire-Deck Thickness on thermal status of cylinder head

Abstract

In this paper, different value of fire-deck thickness on temperature, thermal stress and low cycle fatigue (LCF) life of cylinder head has been discussed and investigated. A 6-cylinder engine has been selected for CFD and thermal analysis. And a half model (3-cylinder) has been used for the stress and corresponding LCF calculation because of the identical structure among cylinders. The thermal condition of cylinder head is calculated with the conjugate heat transfer (CHT) simulation between cylinder head and coolant. The results shows that temperature variation among different cylinders is tiny. With the fire-deck thickness (FDT) increased, the temperature and thermal stress on cylinder head fire-face raised apparently, while the LCF life is reduced. When the FDT increases from 9 to 13, the thermal stress, peak and average temperature on cylinder head fire face is increased by 10.85%, 5.89% and 4.76%, respectively. The corresponding LCF life is reduced from 9875 to 5730 times.