Simplified model for estimations of combustion products, adiabatic flame temperature and properties of burned gas

Abstract

To reduce complications in calculations of mole fractions of combustion products, adiabatic flame temperature and burned gas properties, a simplified calculation of combustion products is proposed in this work. 6 major gas species are considered in burned gas. 6 governing equations are reduced to a fourth degree polynomial equation and it is referred to as quartic combustion model (QCM). The calculations of adiabatic flame temperature, thermodynamic properties and transport properties of burned gas are also presented. The combustions of fuels are simulated using the developed model and the results are compared with those using Chemical Equilibrium and Applications program (CEA) in which 10 gas species are accounted. The comparison results show that, for non-preheated reactant mixture, the mole fractions of major species of combustion products, the adiabatic flame temperature and the thermodynamic properties from QCM are slightly different from that of CEA. Furthermore, the QCM estimates the numbers of moles of the combustion products more precise than that from low temperature combustion model. However, the viscosity and the thermal conductivity calculated using QCM are possibly 4.5% and 5.4% lower than that obtained from CEA, respectively. For the Prandtl number, the QCM gives this property averagely 1% higher than that from CEA.