Flame-flow interactions and flow reversal

Document Type

Conference Proceeding

Publication Date

12-13-2010

Abstract

The interaction of a premixed methane/air flame with flow unsteadiness is studied computationally using a stagnation-point flow configuration. The problem is of fundamental interest and also relevant for turbulent combustion in the laminar flamelet regime. In the present study, of particular interest is the flame residing in a weakly strained flow field such that the flame is stabilized away from the viscous boundary layer adjacent to the stagnation plane and is free to move in response to flow perturbations. An unsteady sinusoidal strain rate field is imposed on the flame, and an extensive parametric study is conducted by varying the frequency and amplitude of strain rate fluctuation. It is found that for high frequencies and large amplitudes, flow direction reverses upstream of the flame, thereby establishing a new stagnation plane in the preheat zone ahead of the flame. This observation indicates that the flame strongly effects the upstream flow field and could also possibly explain the reported occurence of flow reversal in experimental studies of turbulent jet flames. Lewis number effects on flame-flow interaction and flow reversal is studied by investigating highly lean (Le < 1) and rich (Le > 1) hydrogen/air flames. Comparisons of the results are made with an earlier theoretical study of flame-flow interactions incorporating a hydrodynamic model Copyright © 2010 by the authors.

Identifier

78649843934 (Scopus)

ISBN

[9781600867392]

Publication Title

48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

Grant

DMS-0807340

Fund Ref

National Science Foundation

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