CFD analysis of combustion characteristics of CI engine run on biodiesel under various compression ratios

This experimental and numerical study examines the combustion characteristics (CCS) of a Kirloskar four-stroke compression ignition (CI) engine powered by 20% chicken fat biodiesel by volume mixed with diesel fuel (CB20) for three different compression ratios (CRs) of 14: 1, 16.5: 1 and 18: 1. The CI engine used three 0.15 mm diameter fuel injection nozzles to inject fuel at a pressure of 220 bar. Experiments were conducted to measure the engine CCs of the CB20 biodiesel mixed fuel, and output results such as the maximum pressure in the cylinder of each CRs, the volume consumed by the compression stroke, and the volume maintained in the expansion stage by the piston movement were obtained. In the numer-ical analysis, the ANSYS IC engine model was used as a simulation tool to predict the behavior of pressure, volume, heat release rate (HRR) and temperature during piston movement in the combustion chamber at different stages of crank angle. The percentage variation of peak pressure was 7.24, 6.83 and 14.7 bar from simulation is observed for CRs 14:1, 16.5:1 and 18:1 respectively as compared to experimental val-ues. Similarly it is observed that, the HRR in the cylinder at CR 14:1, 16.5:1 and 18:1 are 36.33 J at CA 364, 32.85 J at CA 364 and 27.54 Joules at CA 363 for CFD analysis respectively. Also, the volume profile and temperature inside the cylinder for different CRs indicates that CB20 fuel can be used within the CI engine with no modification to the engine. Thus CFD analysis could be a useful tool for future researchers for combustion modelling. (c) 2021 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the Technology Innovation in Mechanical Engineering-2021.