Experimental investigation on combustion, emissions, performance and cylinder vibration analysis of an IDI engine with RBME along with isopropanol as an additive

An experimental study was conducted to evaluate the combustion, emission, performance and cylinder vibration analysis of an indirect diesel injection (IDI) engine fuelled with rice bran methyl ester (RBME) along with isopropanol as an additive. The additive is used in various percentages (2/98%, 3/97%, 4/96% and 5/95%, by volume) and five discrete part loads (no load, 0.77 kW, 1.54 kW, 2.31 kW, and 2.70 kW) without gear box and clutch assembly, to ensure stable engine operation. Additive is injected through the nozzle in a dual-fuel mode and the injection timings were calculated with reference to 1 L/h. Smoke, NOx, CO, HC and CO2 emissions were recorded and various engine performance parameters were measured. A comparative study was conducted using diesel, RBME and additive blends of RBME on an IDI engine. A substantial improvement can be observed from the net heat and cumulative heat release rate plots in which the 2% additive blend reached the performance of diesel fuel and the corresponding cylinder vibration plots indicated smoother combustion for the above blend. There was a 4.3% hike in thermal efficiency, and 14% CO, 36.5% NOx and 27.5% smoke reductions were observed at 2% additive at full load of the engine.