59063 - Modelling of Turbulent Premixed Flames With Ch4/h2/air Including Influence of Stretch and Heat Losses 

This paper presents a RANS turbulent combustion model for methane/hydrogen/air mixtures which includes the effect of heat losses and flame stretch. This approach extends a previous model [1], designed for methane/air mixtures, and has the potential to improve the prediction of flame stabilization when hydrogen is added to the fuel. The model is based on the calculation of the consumption speed of laminar premixed flames influenced by variations in strain and heat loss in asymmetric counter-flow configurations. The consumption speed depending on strain and heat loss is introduced into a turbulent combustion model based on a progress variable approach. In this implementation a new turbulent flame speed correlation is derived as being a function of flame stretch, heat loss and H2 addition and is validated against turbulent flame speed experimental data available in the literature. The performance of the model is further validated by comparing CFD predictions to experimental data of an atmospheric premixed turbulent bluff-body stabilized configuration [2] which was fed with CH4/H2/air mixtures ranging from pure methane to pure hydrogen.

[1] Tay-Wo-Chong, L., Scarpato, A., Polifke, W., LES Combustion Model with Stretch and Heat Loss Effects for Prediction of Premixed Flame Characteristics and Dynamics, Proceedings of ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition, GT2017-63357, June 26-30, 2017, Charlotte, NC, USA.

[2] Æsøy, E., Aguilar, J., G., Wiseman, S., Bothien, M., R., Worth, N., A., Dawson, J., R., (2020), Scaling and prediction of transfer functions in lean premixed H₂/CH₄-flames, Combustion and Flame, Volume 215, 269 – 282.