Confined superadiabatic premixed flame-flow interaction

Technical Report · Sun Dec 31 04:00:00 EST 1995

DOI:https://doi.org/10.2172/661463· OSTI ID:661463

Najm, H N

Laminar premixed unity-Lewis number flames are studied numerically, to examine flow-flame interaction in a two-dimensional closed domain. Two opposed planar flame fronts are perturbed sinusoidally and allowed to develop by consuming premixed reactants. Combustion heat release leads to global pressure and temperature rise in the domain, due to confinement. A superadiabatic condition, with products temperature rising with distance behind the flame front, is observed due to stagnation pressure rise. Variations in tangential strain rate behind the perturbed flame fronts, due to flame curvature and heat release, result in a modified local superadiabatic temperature gradient in the products. These variations in temperature gradients are shown to determine the net local confinement-heating rate in the products, leading to corresponding deviations in products temperature, and the local reaction rate along the flame front. These observations, which are not consistent with one-dimensional superadiabatic stagnation flame behavior, are a direct result of the unrestrained unsteady nature of two-dimensional flame-flow interaction.

• Research Organization: Sandia National Labs., Livermore, CA (United States)
• Sponsoring Organization: USDOE Assistant Secretary for Energy Efficiency and Renewable Energy, Washington, DC (United States); USDOE Office of Energy Research, Washington, DC (United States)
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 661463
• Report Number(s): SAND--95-8605C; ON: DE97051377
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
COMBUSTION KINETICS
COMBUSTION PRODUCTS
FLAMES
LAMINAR FLOW
MATHEMATICAL MODELS
STAGNATION
THEORETICAL DATA
TWO-DIMENSIONAL CALCULATIONS
VORTEX FLOW