TY - JOUR
T1 - Near wall effects on the premixed head-on hydrogen/air flame
AU - Zhao, Dongxiao
AU - Hernandez Perez, Francisco
AU - Guo, Chenlin
AU - Im, Hong G.
AU - Wang, Lipo
N1 - KAUST Repository Item: Exported on 2022-09-14
Acknowledgements: DZ and LW appreciate the computational support from the Centre for High Performance Computing at Shanghai Jiao Tong University. FEHP and HGI were sponsored by King Abdullah University of Science and Technology (KAUST).
PY - 2022/7/6
Y1 - 2022/7/6
N2 - The paper focuses on laminar and turbulent premixed head-on hydrogen/air flames interacting with inert, non-reacting walls. Both adiabatic and isothermal (450K) walls are considered in a counterflow-like, statistically stationary configuration. In the laminar condition, the flame-wall distance and isothermal-wall heat flux are studied under different strain rates. In the turbulent condition, interactions between turbulent, thermal and chemical effects are analyzed via direct numerical simulations. Influences on the flame dynamics due to near wall effects are characterized by conditional statistics on the flame fronts, such as the flame front temperature, thickness and the heat release rate. Compared with the single-step chemistry results, the detailed chemical reaction mechanism brings new and more complicated physics. Because of the differential diffusion between heat and mass, the flame front topology associated with major species changes with the wall boundaries. Accounting for contributions from various reacting species, a newly defined mean flame displacement speed has been proposed to quantify the movement of the turbulent flame zone. Interestingly, the wall heat flux model developed from the single-step chemistry remains applicable even for the detailed chemistry case with good predictability for both laminar and turbulent flames.
AB - The paper focuses on laminar and turbulent premixed head-on hydrogen/air flames interacting with inert, non-reacting walls. Both adiabatic and isothermal (450K) walls are considered in a counterflow-like, statistically stationary configuration. In the laminar condition, the flame-wall distance and isothermal-wall heat flux are studied under different strain rates. In the turbulent condition, interactions between turbulent, thermal and chemical effects are analyzed via direct numerical simulations. Influences on the flame dynamics due to near wall effects are characterized by conditional statistics on the flame fronts, such as the flame front temperature, thickness and the heat release rate. Compared with the single-step chemistry results, the detailed chemical reaction mechanism brings new and more complicated physics. Because of the differential diffusion between heat and mass, the flame front topology associated with major species changes with the wall boundaries. Accounting for contributions from various reacting species, a newly defined mean flame displacement speed has been proposed to quantify the movement of the turbulent flame zone. Interestingly, the wall heat flux model developed from the single-step chemistry remains applicable even for the detailed chemistry case with good predictability for both laminar and turbulent flames.
UR - http://hdl.handle.net/10754/679728
UR - https://linkinghub.elsevier.com/retrieve/pii/S0010218022002826
UR - http://www.scopus.com/inward/record.url?scp=85133461922&partnerID=8YFLogxK
U2 - 10.1016/j.combustflame.2022.112267
DO - 10.1016/j.combustflame.2022.112267
M3 - Article
SN - 0010-2180
VL - 244
SP - 112267
JO - Combustion and Flame
JF - Combustion and Flame
ER -