Analysis and Simulation of Combustion and Emission on Small Engine

A single cylinder four-stroke spark ignition (SI) engine that fueled by Liquefied Petroleum Gas (LPG) and gasoline are used to predict and analyze the combustion process within cylinder and exhaust gas emissions. A zero-dimensional models are most suitable analytical models for engine cycle simulation. Mass fraction burn is suited for this model to calculate the amount of fuel burn as a function of crank angle during the combustion process within cylinder. The simulation program has been developed using MATLAB software by implementing a single-zone thermodynamic model to analyze the performance parameters of spark ignition (SI) engine. This model is categorized into sub-models such as combustion model, heat transfer model and exhaust gas emissions model. The first law of thermodynamics is applied to this model and Annand’s model was used to compute the convection and radiation of heat transfer within cylinder. The engine performance parameters computed including the in-cylinder pressure, gas temperature, net heat release, mass fraction burn, brake power, torque, indicated specific fuel consumption. Then, the nitric oxide and hydrocarbon of exhaust emission in the cylinder was predicted by the formation of the emission model. The results of engine performance are compared between gasoline and LPG as a fuel.

Keywords: small (SI) engine, LPG fuel, gasoline fuel, performance, emission.

M.M.Noor