Abstract
The total world energy consumption is estimated 500*10^15 BTU (119.5*10^15 Watt) as of year 2008, out of which 86.5% of all the energy consumption is derived from the combustion of fossil fuels. Fossil fuels produce large amount of energy, however they produce carbon dioxide emissions, which go back to the atmosphere, whereas biofuels produce energy without causing a net increase of carbon in atmosphere. Higher fuel prices and global warming will lead to increase use of alternative source of energy or renewable energy. One alternative form of energy is biomass (e.g. wood straw, animal waste etc.). In order to have better understanding of the heat energy generation from natural gas and biofuels, a combustion model is needed. Hence, a Computational Fluid Dynamics (CFD) model for combustion of methane and air was created and validated. Study of combustor wall temperature, flame temperature, turbulent kinetic energy and the flame location was performed for different conditions. The simulated results for adiabatic flame temperature and 0 =0.8 show Oto 7.85% error when compared with analytical results. The percentage error obtained for mass fraction and mole fraction of species at inlet and outlet is almost zero when compared with analytical results. The flame temperature increases linearly with equivalence ratio. At high inlet velocity, convective heat transfer resistance in the combustor decreases hence, there is small amount of increase in total heat flow. In addition to this as the flow rate increases the inner wall temperature of the combustor increases, temperature of the flame decreases in post combustion zone due to heat loss to the surrounding. The rate of reaction increases linearly with the inlet velocity and decreases with increase in equivalence ratio, however the flame location remains constant.