CFD Simulation of Producer Gas Fuelled SI Engine

Abstract

Syngas generated from the thermochemical conversion of biomass in a gasifier is increasingly being used for fuelling internal combustion engines, especially for distributed power generation. Producer gas as a fuel has thermo physical properties significantly different from those of conventional fuels. As of date, there are no dedicated engines for alternative fuels in general and producer gas in particular. A review of the available literature indicates experimental experience with producer gas but very little information on modelling and simulation studies are available. While experimental investigations provide actual performance parameters, the information is essentially spatial or temporal average only. Apart from that, fluid dynamic and combustion progress parameters cannot be acquired inexpensively. The current work primarily addresses the combustion progression parameters in a typical spark ignited engine under naturally aspirated and turbocharged after cooled configuration at varying mixture quality using the ANSYS FLUENT computational fluid dynamics software. The CHEMKIN software is used for determining the laminar flame speed for producer gas as a function of the mixture quality. Spatially averaged pressure traces from the simulation are compared with literature pressure traces at the desired condition and various simulation parameters are tuned till a match between the literature and simulation pressure is obtained. Once the simulation is validated, the progress of combustion parameters is derived from the simulation in post processing.