Flow-flame interaction in a closed chamber
Artikel i vetenskaplig tidskrift, 2008

Numerous studies of flame interaction with a single vortex and recent simulations of burning in vortex arrays in open tubes demonstrated the same tendency for the turbulent burning rate proportional to U-rms lambda(2/3), where U-rms is the root-mean-square velocity and lambda is the vortex size. Here, it is demonstrated that this tendency is not universal for turbulent burning. Flame interaction with vortex arrays is investigated for the geometry of a closed burning chamber by using direct numerical simulations of the complete set of gas-dynamic combustion equations. Various initial conditions in the chamber are considered, including gas at rest and several systems of vortices of different intensities and sizes. It is found that the burning rate in a closed chamber (inverse burning time) depends strongly on the vortex intensity; at sufficiently high intensities it increases with U-rms approximately linearly in agreement with the above tendency. On the contrary, dependence of the burning rate on the vortex size is nonmonotonic and qualitatively different from the law lambda(2/3). It is shown that there is an optimal vortex size in a closed chamber, which provides the fastest total burning rate. In the present work, the optimal size is six times smaller than the chamber height.

RADIATED SOUND

HIGH-TEMPERATURE

LARGE-EDDY SIMULATION

ACOUSTIC INSTABILITY

LARGE-SCALE

HIGH-PRESSURE

FRONT PROPAGATION

WEAKLY TURBULENT

TURBULENT PREMIXED FLAMES

BURNING VELOCITIES

Författare

V. Akkerman

Technische Universiteit Eindhoven

Stanford Center for Turbulence Research

Umea universitet

V. Bychkov

Umea universitet

R. J. M. Bastiaans

Technische Universiteit Eindhoven

Stanford Center for Turbulence Research

L. P. H. de Goey

Technische Universiteit Eindhoven

J. A. van Oijen

Technische Universiteit Eindhoven

Lars-Erik Eriksson

Chalmers, Tillämpad mekanik, Strömningslära

Physics of Fluids

1070-6631 (ISSN) 1089-7666 (eISSN)

Vol. 20 21-

Ämneskategorier

Maskinteknik

DOI

10.1063/1.2919807