Analysis on a thermal barrier coated (TBC) piston in a single cylinder diesel engine powered by Jatropha biodiesel-diesel blends

The objective of the present work is to enhance the performance of a diesel engine using a thermal barrier coated piston operated with Jatropha biodiesel-diesel blends. For thermal barrier coating, Yttria stabilized zirconia (YSZ) is preferred owing to its high heat insulation capabilities in comparison with other insulating materials such as mullite, zirconia, ceramics, magnesium silicate, silicon carbide etc. YSZ is coated via a plasma spray technique at around 200 mu m thickness around the piston crown. The test fuel utilized are DF100 (100% diesel fuel), JB20NE (20% Jatropha biodiesel + 80% diesel fuel operated at normal un-coated engine) and JB20CE (20% Jatropha biodiesel + 80% diesel fuel operated at YSZ coated engine). Experimental results revealed that JB20CE has resulted in 10.6% increased brake thermal efficiency and 20.97% lowered brake specific fuel consumption since the YSZ coating acts as a potential insulator in retaining maximum heat inside the combustion chamber, lowering the energy losses followed by improved combustion efficiency, enhanced air-fuel mixture formation and higher performance. Emission wise, JB20CE operation resulted in lowered hydrocarbon and carbon monoxide emissions by about 41.67% and 33.33% due to improved fuel oxidation and effective combustion provided by YSZ insulation.