Numerical analysis of confined and unconfined hydrogen turbulent flames

In this study, CFD modelling of confined and unconfined turbulent jet flames were carried out. Investigations were performed for different air:fuel ratios including stoichiometric conditions. Confined and unconfined combustions of hydrogen were investigated for different power inputs. As the combustion chamber is cylindrical and axisymmetrical, CFD modelling was made two dimensional and axisymmetrical. As a result of the modelling, temperature distributions, velocity distributions and gas concentrations including NOx emissions were obtained. It is shown that maximum temperature and maximum NOx emissions occur at the confined condition of hydrogen combustion. It is also shown that the value of NOx emissions in low-temperature zones are less than the value of NOx emissions in high-temperature zones in all combustion conditions. Copyright (c) 2011 John Wiley & Sons, Ltd.