A numerical study of thin flame representations

Conference · Fri Aug 11 00:00:00 EDT 1989

OSTI ID:5606725

Rotman, D A; Pindera, M Z

In studies of reacting flows, the flame may be viewed as a moving discontinuity endowed with certain properties; notably, it acts as a source of velocity and vorticity. Asymptotic analysis shows this to be justified provided that the flame curvature is small compared to the flame thickness. Such an approach is useful when one is interested in the hydrodynamic effects of the flame on the surrounding flowfield. In numerical models of this kind it is customary to treat the discontinuity as a collection of discrete velocity blobs. In this study, we show that the velocities associated with such a representation can be very non-smooth, particularly very near to the flame surface. As an alternative, we propose the use of a finite line source as the basic flame element. Comparisons of the two flame representations are made for several simple test cases as well as for a flame propagating through an enclosure forming the tulip shape. The results show that the use of line sources eliminates spurious fluctuations in nearfield velocities thus allowing for a more accurate calculation of flame propagation and flame-flowfield interactions. 7 refs., 15 figs.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5606725
• Report Number(s): UCRL-100261; CONF-890739-5; ON: DE89017889
• Resource Relation: Conference: 12. international colloquium on the dynamics of explosions and reactive systems, Ann Arbor, MI, USA, 23-28 Jul 1989; Other Information: Portions of this document are illegible in microfiche products
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
FLAME PROPAGATION
MATHEMATICAL MODELS
COMBUSTION PROPERTIES
EQUATIONS
FLOW MODELS
FLUID MECHANICS
HYDRODYNAMICS
VELOCITY
VORTEX FLOW
FLUID FLOW
MECHANICS
400800* - Combustion
Pyrolysis
& High-Temperature Chemistry
990230 - Mathematics & Mathematical Models- (1987-1989)