Evaluation of flow and flame characteristics of turbulent bluff-body CH₄-H₂ flame using LES-FPV approach

ABSTRACT

This study investigated the flow and flame structure of a bluff-body stabilised CH₄-H₂ flame using the large eddy simulation (LES) and the flamelet progress variable (FPV) model. The performance of three subgrid-scale (SGS) LES models, i.e. the standard Smagorinsky model (SSM), the wall-adapting local eddy viscosity (WALE) model, and the dynamic Smagorinsky model (DSM) in predicting turbulent and reactive flow characteristics was assessed. Parameters, namely y⁺, Pope index (M), vorticity field, and resolved turbulent kinetic energy (k_t), were analysed to determine the predictive capability of the three models. The results demonstrated that DSM and WALE successfully resolved 80% of k_t for chosen grid configurations, whereas SSM exhibited discrepancies. The overall trends captured by all three models matched well with the experimental trend with DSM and WALE outperforming SSM in predicting reacting flow fields in the recirculation zone, while SSM produced better predictions in the regions away from the recirculating zone.

KEYWORDS:

• Tabulated chemistry
• bluff body flame
• flamelet progress variable
• large eddy simulation

Acknowledgements

The authors would like to acknowledge High-Performance Computing facility at IIT Goa.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The authors acknowledge the support of Indian Institute of Technology (IIT) Goa towards this research work through the project 2018/RNR/SG/007. This research was also partially supported by the Science and Engineering Research Board (SERB), India, through the project CRG/2021/001335.