A 3D modelling of the in-cylinder combustion dynamics of two stroke internal combustion engine in its service condition
In this study, a two stroke internal combustion engine was successfully modeled as a closed cycle with the intake, compression, expansion and exhaust processes considered in two strokes of the reciprocating piston. The in-cylinder combusted gases with respect to air-fuel mixture of 14.4:1 in the two stroke engine model were analyzed, showing the dynamics of the combusted gases, the flame pressure and temperature trajectories. It was observed that provided compression and expansion takes place at air-fuel mixture near ideal condition (14.7:1), the combusted gas temperature which occurred in the range of 293.92-3000.60 K is directly proportional to the cylinder gas pressure which occurred in the range of 60.76-80.20 bar. With a heat transfer coefficient of 581.236 W/m2K, the maximum temperature of the IC engine material was found to be 2367.56K at equilibrium and the maximum shear stress was found to be 176 x 102 MPa (1.76 x 105 bar). The 14.4:1 air-fuel mixture implies that 26% O2, 73% N2 and 1% trace gases are the in-cylinder air constituent that will react with 1 mole of hydrocarbon to form the combusted products of 96.2% CO2, 3.2% H2O and 0.6% N2. This will vary in conditions where the air-fuel mixture changes.
Keywords: Modelling, Gas dynamics, Two stroke, IC engine, Air-fuel mixture.