Akademik Veri Yönetim Sistemi
Fuel, cilt.381, 2025 (SCI-Expanded)
This study aims to provide a comprehensive insight into conjunct impact of CuO and Cu/Ag nanoparticles (NPs) incorporation into karanja oil biodiesel-diesel fuel blend (B20) and 5W-30 lubricant on tribological behavior, noise-vibration, performance and emission characteristics of a single cylinder diesel engine. Morphology and dispersion characteristics of NPs in both B20 and engine oil were observed via scanning electron microscopy (SEM), dynamic light scattering (DLS), and zeta potential (ζ–p) analyses to determine the optimum concentration in both fluid ambients. Related analyses depicted that dispersion of CuO in B20 fuel was better than that of Cu/Ag whereas the sedimentation of the latter was lower than that of CuO in 5W-30. Besides, optimal concentrations of CuO and Cu/Ag in B20 were found to be 0.5 wt% (B20CuO0.5) and 0.2 wt% (B20CuAg0.2), respectively. The optimal fractions of CuO and Cu/Ag in 5W-30 oil were specified as 1.5 wt% (5W30CuO1.5) and 1 wt% (5W30CuAg1.0) which were also confirmed by viscosity analysis. Fuel properties of B20 and nanofuels were close to those of Eurodiesel fuel (ED). Thermogravimetric (TG) analysis was conducted to specify the thermal stability of the NPs under harsh abrasion conditions. The samples directly cut from the spare piston rings of the test engine underwent friction tests to procure coefficient of friction (COF), wear rate, and surface roughness within the nanofuel and nanolubricant bath in order to unravel the lubricity enhancement features of NPs in both fuel and lubricant. The detailed images and chemical composition of the fretted surfaces were achieved via atomic force microscopy (AFM), and energy dispersive X-ray (EDX) to confirm the effectiveness of NPs on tribological performance. The acoustic of the engine operating with various fuels and optimum lubricant combination was also observed considering vibration acceleration and noise level data taken from block and head of the engine. Thermal efficiency (ƞt) of the engine was found to be 16 % for B20CuO0.5 and 5W30CuAg1.0 engine operation whereas it was 17 % for ED. Brake specific fuel consumption (BSFC) values of operation with nanofuels were only 3–6 % higher than that of ED due to enhanced tribological performance. For nanofuel operation, in-cylinder pressure was prone to depict a steep increase up to 3.4 MPa during compression and initial stages of power stroke. The maximum heat release rate (HRR) was 7.6 cal/°CA for B20CuO0.5 subtending to 10 % increase when compared with ED. Nanofuel operation provided considerable amount of reductions in CO, UHC and soot emissions up to by 10.5 %, 7 %, and 15 %, respectively thanks to their better combustion characteristics and tribological performance. Good heat transfer characteristics of metallic NPs and fast combustion of nanofuels yielded a reduction in combustion temperature and NOx emissions until the load of 50 %. At high loads, longer combustion period of ED ensured better HRR leading to lower combustion temperatures and lower NOx. Nonetheless, the average NOx emission values of B20CuO0.5 was only 6.5 % higher than that of ED. Acoustic analysis at 1700 rpm and full load demonstrated that nanofuels, in general, were also effective on reduction of vibration and noise of the engine thanks to their better resistance to knock and smoother engine operation achieved via better combustion and reduced friction. Because CuO and Cu/Ag nanoparticles have the potential to significantly improve the combustion and emission characteristics, tribological behavior, and acoustic performance of ICEs, this extensive study can be used as a valuable guide in the development of more efficient and quieter engines.