A numerical support of leading point concept
Journal article, 2022

Unsteady three-dimensional Direct Numerical Simulation (DNS) data obtained from 16 statistically planar and one-dimensional, complex-chemistry, lean (equivalence ratio is
equal to 0.50 or 0.35) hydrogen-air flames propagating in forced, intense, small-scale turbulence (Karlovitz number up to 565) are reported. The data are analyzed to compare roles played by leading and trailing edges of a premixed turbulent flame brush in its propagation. The comparison is based on the following considerations: (i) positively (negatively) curved reaction zones predominate at the leading (trailing, respectively) edge of a premixed turbulent flame brush and (ii) preferential diffusion of molecular or atomic hydrogen results in increasing the local fuel consumption and heat release rates in positively or negatively, respectively, curved reaction zones. Therefore, turbulent burning velocities computed by deactivating differential diffusion effects for all species with the exception of either H2 or H are compared for assessing roles played by leading and trailing edges of a premixed turbulent flame brush in its propagation. By analyzing the DNS data, a significant increase in the local fuel consumption and heat release rates due to preferential diffusion of H2 or H is documented close to the leading or trailing, respectively, edges of the studied flame brushes. Nevertheless, turbulent burning velocities computed by activating preferential diffusion solely for H2 are significantly higher than turbulent burning velocities computed by activating preferential diffusion solely for H. This result indicates an important role played by the leading edge in the propagation of the explored turbulent flame brushes

Lewis number

turbulent burning velocity

leading point concept

turbulent combustion

preferential diffusion

Author

Hsu Chew Lee

Southern University of Science and Technology

Peng Dai

Southern University of Science and Technology

Minping Wan

Southern University of Science and Technology

Andrei Lipatnikov

Chalmers, Mechanics and Maritime Sciences (M2), Combustion and Propulsion Systems

International Journal of Hydrogen Energy

0360-3199 (ISSN)

Vol. 47 55 23444-23461

Subject Categories

Energy Engineering

Fluid Mechanics and Acoustics

Roots

Basic sciences

Driving Forces

Innovation and entrepreneurship

DOI

10.1016/j.ijhydene.2022.05.140

More information

Latest update

7/15/2022