Temperature and stress examinations on pistons for damage prevention and efficiency enhancement: Carbon/carbon composite piston vs. conventional aluminum pistons
By identifying well-known failures in pistons, uniquely on skirt area where overlapping with cylinder mainly occurs and causing pistons to fail are investigated. Hence, aim of this paper is to compare two different pistons by analyzing their temperature and stress/strain distributions on specific areas, specifically crown and skirt. By considering the unique properties of carbon, mainly the low coefficient of thermal expansion, density and toughness; expectations in carbon/carbon pistons seemed highly promising compared to conventionally used aluminum pistons. Furthermore, necessary analyses are made by a finite element software package, AbaQus. It is observed that the usage of carbon/carbon composite as a material for pistons shows a high thermal durability which is crucial for necessary cooling stage than aluminum due to its low thermal conductivity property. It is also shown that compared to aluminum, carbon/carbon pistons are 30% lighter in weight, more resistible to mechanical loadings such being pressure, inertial loadings, side forces, and thermal effects. Carbon/carbon composite piston's tolerance to higher Von Mises stresses around 489 MPa and temperatures up to 664 °C shows a clear superiority when compared to aluminum. Carbon/carbon composite pistons are also much more relevant to be used in an engine for weight reduction and increasing clearance tolerance down to 0.01 mm between the piston and cylinder liner which indirectly reduces the mass of components and directly reduces side forces by a longer connecting rod usage allowance.
Proceedings of the ASME Design Engineering Technical Conference
Kaán, M., & Keleştemur, M.H. (2015). Temperature and Stress Examinations on Pistons for Damage Prevention and Efficiency Enhancement: Carbon/Carbon Composite Piston vs Conventional Aluminum Pistons, 10. Doi: 10.1115/DETC2015-46042.