CFD simulation in annular combustion chamber of proto X-3 bioenergy micro gas turbine

Numerical investigation of the combustion in annular combustion chamber of micro gas turbine using Computational Fluid Dynamics (CFD) simulation with CFDSOF® solver is presented in this study. The aim is to investigate the phenomenon of combustion to determine the optimum operating conditions of the combustion chamber that meet the requirements of micro gas turbine and the quality of the emission into the environment. In this study, the mathematical models used for the simulations were finite rate and eddy dissipation for combustion and standard k-ε for turbulent flow. The Compressed Natural Gas (CNG) fuel was used for the simulations and assumed to be 100 kW and 100% methane (CH₄). Four different air mass flow rates were tested: 0.1, 0.12, 0.16 and 0.2 kg sec^-1,. The simulations showed that the hottest zone in the combustion chamber was found right in front the dilution zone and it confirmed the results of various experiments and simulations of combustion of methane. The air mass flow rate of 0.12 kg sec^-1, gave the optimum result for the system because it produced gas with temperature of 1089 K that meets the requirement of the micro gas turbine while the other rates gave higher or lower value. The emissions of the rate of 0.12 kg sec^-1, in term of NO_x, CO₂ and H₂O, also gave good results.