Experimental investigation of the effect of liquid petroleum gas on frictional power loss for performance enhancement of SI engine

Alternative gaseous fuels being clean, economical, and available in large quantity encourage the focus on optimizing various operating conditions for internal combustion engines. Alternative fuel as LPG is being considered to restore the role of alternative fuel to improve fuel economy by reducing fuel consumption and total frictional power loss compared to petrol fuel. The engine is tested using LPG and petrol so that comparison of the engine performance concerning fuel consumption and frictional power loss using Morse test. The conventional 4 Cylinder, 4 Stroke Spark Ignition engine expending a hydraulic dynamometer is used for experimentation. To find the most influencing factors from various input parameters of an engine like engine speed, load on the engine, engine oil viscosity which strongly affects engine frictional power loss. The comparative analysis of petrol and LPG fuels with different multi-grade engine oils shows that the mechanical efficiency obtained from the Morse test are 68.37%, 65.75% and 64.69% at 1750 rpm for petrol fuel with SAE20W30, SAE05W40 and SAE20W50 respectively, while for the same operating condition these values with LPG fuels are 62.99%, 61.85% and 59.85% respectively for SAE20W30, SAE05W40 and SAE20W50 engine oils at1750 rpm. Buckingham Pi-theorem is used to calculate, an experimental data-based mathematical model for which various pi-terms are determined, applying dimensional analysis for selected parameters for predicting outcomes as frictional power loss and fuel consumption rate.