Pistons of DI-Diesel Engines with Reduced Heat Flow

Three different piston designs were fitted to a turbo-charged, intercooled diesel engine with cylinder diameter of 130 mm as follows:

• standard aluminum piston with casting gallery
• articulated piston with steel crown and aluminum skirt
• nodular cast iron piston with shrink fit ceramic section.

The temperature distribution and thermal balance of the piston designs were calculated as a function of mean effective pressure, based on extensive temperature measurements and with the help of the Finite Element Method.

The heat flowing into the piston affects the engine oil, the cylinder, the rings and the piston pin. The significantly varying heat flows are quoted as a function of mean pressure for each piston design.

The heat balance of articulated pistons with and without sprayed on ceramic coatings and their thermal deformations are compared.