The influence of thermal barrier coating on an LHR engine fueled by soybean biodiesel blended with various additive spectrums: Performance,combustion, and emission analysis

The novelty of this research work deals with green synthesized nanoadditives (5% of graphene, carbon nanotubes, and carbon black), oxygenated additives (5% of n-butanol, n-heptane, and n-pentanol), and then the test fuels are prepared by blending of 20% of soybean biodiesel and 70%, 80%, and 100% of premium diesel. The experimental outcomes revealed that the Nickel Chromium Aluminum (NiCrAl-120 micron), partially stabilized zirconia, and titanium dioxide ceramic composites at about 400 microns achieve the thermal barrier coat of low heat rejection (LHR) engine parts by the air-plasma spray method. Compared with Blend B, green synthesized carbon black (5%), premium diesel (70%), and n-pentanol (5%) mixed soybean biodiesel (20%) fuel (Blend E) tested on the LHR engine achieved 4.90% higher brake thermal efficiency and 25.31% lower brake-specific fuel consumption at peak load owing to the presence of an oxygenated agent (n-pentanol) in the fuel blend, which minimizes carbon deposition. The carbon monoxide, hydrocarbon, NO_x, and smoke emissions were reduced by 25.58%, 29.41%, 5.06%, and 7.75% when compared to Blend B at peak load. Then, the in-cylinder pressure and heat release rate were found to be 4.52% and 8.87% higher for Blend E at peak load compared to Blend B. This was because the mix of oxygenated additive and carbon black bio-based nanofuels made the combustion process go faster. These fuel blends were tested on LHR diesel engines at various load conditions.