Abstract
KEYWORDS – Dual fuel engines, CFD, PVM-MF, Injection, Combustion
ABSTRACT –
Dual fuel engine combustion features both diffusive (as in CI engines) as well as premixed (as in SI engines) combustion processes which make it relatively complex to understand in comparison of combustions in conventional engines. In present study, an effort has been made in describing the complex dual fuel combustion phenomena and also effect of start of injection timing of pilot diesel fuel on diesel-natural gas dual fuel engine performance and emissions has been discussed. A commercial 3-D CFD engine simulation tool ‘STAR-CD’ in conjunction with moving mesh generation tool ‘es-ice’ was used to describe complex dual fuel combustion process. To validate the STAR-CD CFD code, PVM-MF (progress variable model – multi fuel) combustion model was taken into consideration which has specially been developed to characterize the combustion involving more than one fuel. Spray evolution and combustion process has been analyzed in a sector of engine cylinder chamber which reduces the computational time during simulations. It was found out that numerically simulated data was in good agreement with the experimental data. Advanced pilot injection timing showed improvement in the engine performance as well as in CO and soot emissions.