This study investigates the influence of Silica-Diamond-Like Carbon (Si-DLC)
coated pistons on performance metrics of diesel engine fuelled with various
blends of Cassia Fistula biodiesel (CFBD10, CFBD20, CFBD30, and CFBD40). The
primary focus is on key performance metrics, including Brake Thermal Efficiency
(BTE), Brake Specific Energy Consumption (BSEC), and Exhaust Gas Temperature
(EGT). The results demonstrated improvement in BTE and EGT, alongside a
reduction in BSEC across all biodiesel blends compared to conventional diesel.
Specifically, at full engine load, CFBD10 exhibited a BTE of 33.41%, which is
3.17% higher than neat diesel in the stock engine. At part load and no-load
scenarios, improvements of 2% and 0.51% over neat diesel were recorded. During
no-load conditions, the BSEC for CFBD10 was measured at 9.901 MJ.kW-hr, 0.738
MJ.kW-hr lower than that of neat diesel. Further increases in Cassia fistula
blends resulted in higher BSEC values due to lower calorific content. Exhaust
gas temperatures at higher loads were recorded at 330°C, 374°C, 368°C, 360°C,
and 351°C for diesel, CFBD10, CFBD20, CFBD30, and CFBD40, respectively, with
CFBD10 outperforming neat diesel by 44°C. Specifically, the Si-DLC coating
significantly contributes to improved combustion efficiency and thermal
management, resulting in higher BTE and EGT. Concurrently, the optimized
combustion process facilitated by the Si-DLC coating leads to a decrease in
BSEC, indicating a more efficient energy utilization. The scope of this research
extends to analysing the implications of Si-DLC coatings in the broader context
of automotive engine efficiency and sustainability. These findings underscore
the potential of Si-DLC coated pistons in promoting cleaner and more efficient
automotive energy solutions. The study aligns SDG 7 (Affordable and Clean
Energy) and SDG 13 (Climate Action), by advancing the development of sustainable
biodiesel technologies that enhances energy efficiency in the transportation
sector.