ABSTRACT
The current study deals with a reactivity-controlled compression ignition (RCCI) engine working with 1-pentanol as the LRF and JOBD as the HRF. The composition of the pilot fuel includes 20% Jatropha oil and 80% diesel, which nearly matches the heating value and cetane index of petroleum diesel. The research focuses on studying the impact of the pilot fuel injection angle on the engine characteristics at full load conditions, and the pilot fuel injection angle varies from 19, 21, 23, 25, to 27° bTDC at a constant injection pressure of 600 bar. The results revealed that increasing the pilot fuel injection angle increased the engine performance with a 13.36% rise in BTE, a reduction in CO emissions by 11.03%, and a decrease in HC emissions by 9.28% at a pilot fuel injection angle of 25° bTDC at 30% pentanol energy share (BD70P30). On the other hand, NOx emissions rise by 11.07%. The results indicate that the performance of the ternary fuelled RCCI engine can be improved by increasing the fuel injection angle of the pilot fuel.
Subject(s)
Jatropha , Pentanols , Vehicle Emissions , Biofuels , GasolineABSTRACT
Thermal energy conversion and storage plays a vital role in numerous sectors like industrial processing, residential and mass cooking processes, thermal management in buildings, chemical heating, and drying applications. It will also useful in waste heat recovery operations in industrial/thermal power stations. The effect of Al2O3 nanoparticle volume fraction (0%, 2%, and 5%) in a paraffin phase change material (PCM) and heater location (Bottom and Sidewall) in a 2D square thermal energy storage system have been numerically analyzed in this study. Transient thermal analysis has been carried out in ANSYS Fluent R18.1 for 500, 1000, and 3000 s. Laminar flow conditions with an enthalpy porosity model are used to study the solidification and melting behavior of nano-PCM. A Grid independence test has been conducted and selected an optimum number of elements as 115538. The results revealed that the addition of nanoparticles in PCM improves its thermal characteristics. The variation of liquid fraction and temperature profile with time has been recorded, and this is due to Rayleigh-Benard convection. At a given time, the melting rate increases with an increase in nanoparticle concentration up to 2% insertion after that the melting fraction reduces for both bottom wall and sidewall heating. This is mainly due to viscous domination with the increase in physical characteristics like density and viscosity of the fluid. Also, the melting rate in the case of sidewall heating augmented more than the bottom wall heating due to negligible buoyancy effects in former than later. The outcome of this analysis helps to find out the optimum volume concentration of nanoparticles to maximize the thermal energy storage applications.
