Flame Radius Effects on a Sequential Ignition Engine Characteristics

Abstract

The effects of the flame radius and flame propagation have been investigated at a sequential ignition engine with numerically. A single cylinder of the sequential ignition engine was modeled in STAR-CD/es-ice software for the gasoline usage taking into account all components related to the combustion chamber. The effect of flame on engine characteristics is the function of flame radius and flame thickness. In the numerical analysis, compression ratio is 10.8:1, air-fuel ratio is 1.2, ignition advance at 30-25 CAD, engine speed is 3000 rpm and the flame thickness is 0.0001 m were kept constant. The analysis, k-? RNG turbulence model, Angelberger wall interaction and G-equation combustion model were used and optimum flame radius value was determined. Three different analysis were carried out to determine the effect of the flame radius and the flame radius was changed to 0.0005 m, 0.0010 m and 0.0020 m, respectively. As a result of the study, images of flame formation and propagation were obtained for the time period up to the top dead center at the time of sequential ignition. The effects of flame radius on CO2 formation and NOx formation were evaluated. The net work area was obtained from the highest engine power and pressure-volume graph when the flame radius was 0.0010 m for the specified operating conditions.