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arXiv · 1008.5044

Non-linear simulations of combustion instabilities with a quasi-1D Navier-Stokes code

Nils Erland L. Haugen·Øyvind Langørgen·Sigurd Sannan
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Abstract

As lean premixed combustion systems are more susceptible to combustion instabilities than non-premixed systems, there is an increasing demand for improved numerical design tools that can predict the occurrence of combustion instabilities with high accuracy. The inherent non-linearities in combustion instabilities can be of crucial importance, and we here propose an approach in which the one-dimensional Navier-Stokes and scalar transport equations are solved for geometries of variable cross-section. The focus is on attached flames, and for this purpose a new phenomenological model for the unsteady heat release from a flame front is introduced. In the attached flame method (AFM) the heat release occurs over the full length of the flame. The non-linear code with the use of the AFM approach is validated against results from an experimental study of thermoacoustic instabilities in oxy-fuel flames by Ditaranto and Hals [Combustion and Flame, 146, 493-512 (2006)]. The numerical simulations are in accordance with the experimental measurements and both the frequencies and the amplitudes of the resonant acoustic pressure modes are reproduced with good accuracy.

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Nils Erland L. Haugen, Øyvind Langørgen, Sigurd Sannan. 2010-08-30. Non-linear simulations of combustion instabilities with a quasi-1D Navier-Stokes code. https://doi.org/10.1016/j.jsv.2011.06.023

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