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Large Eddy Simulations of Buoyant Plumes.

pdf icon Large Eddy Simulations of Buoyant Plumes. (348 K)
Mell, W. E.; Johnson, A.; McGrattan, K. B.; Baum, H. R.

Combustion Institute/Eastern States Section. Chemical and Physical Processes in Combustion. Proceedings. Fall Technical Meeting, 1995. October 16-18, 1995, Worcester, MA, 187-190 pp, 1995.


combustion; buoyant plumes; simulation; equations; combustion models


An approach to the study of gas phase combustion and convection processes in fires using a combination of mathematical analysis and computer simulation is presented. It seeks to solve the governing equations directly (if approximately) by decomposing the fire into a large scale convective and radiative transport problem coupled to a small scale model of combustion and radiative emission. The combustion model assumes that all of the thermodynamic properties of the fluid are tied to the local mixture fraction, which is convected by the large scale motion, which in turn is driven by the heat released by the combustion processes. The large scale flow is studied using finite difference techniques to solve large eddy simulations of the Navier-Stokes equations. As a first test of the numerical approach, a buoyant helium plume is simulated and results compared to a companion laboratory experiment.