A review of thermal barrier coatings for improvement in thermal efficiency of both gasoline and diesel reciprocating engines

Cylinder wall heat insulation using thermal barrier coatings is both an old and new thermal efficiency improvement technology for internal combustion engines. This review first outlines the history of thermal barrier coating (TBC) technologies applied to reciprocating engines from the 1970s up to the present day, by referring to several distinctive reference papers. These research efforts, however, present a number of conflicting conclusions. In order to understand why the results did not always coincide, certain key features of TBC’s studied in the reference papers were then investigated in more detail, such as thermal properties, porosity, surface roughness, and translucence/emissivity. The studies of not only the effect of TBC’s on diesel exhaust emissions, but TBC effects on gasoline and HCCI performance and exhaust emissions, are also reviewed for the investigation of manifold TBC characteristics. Finally, state of the art techniques and constraints were reviewed for experimental and numerical analysis of the heat transfer mechanism, which should be applied to TBC research.