Search

Purpose The purpose this experimentation is to study the combustion characteristics of compression ignition engine fuelled with mineral diesel. The reason behind the numerical simulation is to validate the experimental results of the combustion characteristics. Design/methodology/approach The numerical analysis was carried out in this study using MATLAB Simulink, and the zero dimensional combustion model was applied to predict the combustion parameters such as in cylinder pressure, pressure rise rate and rate of heat release. Findings Incorporating the dynamic combustion duration with respect to variable engine load in the zero dimensional combustion model using MATLAB Simulink reduced the variation of experimental and numerical outputs between 5.5 and 6 per cent in this analysis. Research limitations/implications Validation of the experimental analysis is very limited. Investigations were performed using zero dimensional combustion model, which is the very appropriate for analysing the combustion characteristics. Originality/value Existing studies assumed that the combustion duration period as invariant in their numerical analysis, but with the real time scenario occurring in CI engine, that is not the case. In this analysis, mass fraction burnt considering the dynamic combustion duration was incorporated in the heat transfer model to reduce the error variation between experimental and numerical studies.

Purpose Vast areas have been studied toward combustion and emission analysis in vegetable oil methyl esters and quite a few in algal oil biodiesel. To analyze the better alternate source for diesel engine, this study aims to investigate the combustion behavior and emission characteristics between cottonseed biodiesel and algal oil biodiesel on comparison with mineral diesel in a compression ignition engine. Design/methodology/approach The fuel properties like density, kinematic viscosity, calorific value and Cetane number have met the biodiesel standards for both algal and cottonseed biodiesel. At rated power, engine was operated on all three test fuels, where combustion analysis describing in-cylinder pressure, peak pressure, rate of pressure rise and rate of heat release and emission characteristics including hydrocarbon (HC), carbon monoxide (CO), oxides of nitrogen (NOx) and smoke for both biodiesel comparing mineral diesel. Findings Algal and cottonseed biodiesel showed up to 2-3°CA delayed start of combustion comparing mineral diesel curve. The in-cylinder pressure of algal biodiesel was found to be 68 bar, whereas cottonseed biodiesel exhibited 65 bar at full load condition. Similarly, the rate of pressure rise and rate of heat release of algal biodiesel depicted 7.9 and 10.7 per cent rise than cottonseed biodiesel, respectively. As the load increased, ignition delay showed decreasing trend, while combustion duration showed an increasing trend. HC, CO and smoke emissions were seen to be lower than mineral diesel with noticeable increase in NOx emission. Originality/value In this present investigation, biodiesel from Stoechospermum Marginatum, a marine marco algae, was used to fuel the compression ignition engine. Its combustion behavior and emission characteristics are compared with cottonseed biodiesel, a vegetable oil-based biodiesel having similar physio-chemical characteristics to understand the suitability of algal biodiesel in compression ignition engine. This study involves the assessment of straight biodiesel from macro algae and cottonseed oil on standard operating conditions.