Effect of secondary fuel injection on combustion instability in a model ramjet combustor using V-gutter type flame holder
- Paper number
IAC-09.C4.8.3
- Author
Mr. Byung Hoon Park, Yonsei University, Korea, Republic of
- Coauthor
Prof. Woongsup Yoon, Korea, Republic of
- Year
2009
- Abstract
Ramjets exhibit undesirable combustion instabilities under certain operating conditions. The low frequency, large-amplitude pressure oscillations can create significant practical problems by producing excessive mechanical vibrations and thermal loads to the engines, and cause structural damage and performance degradation. Combustion instabilities in liquid-fueled ramjet combustors are very complicated phenomena because of large number of nonlinear physical couplings between mixing, vortex shedding, recirculation zones, acoustic, and unsteady heat release. Large vortex structures shed from the flame holder in the combustor, which coupled with combustion process are prone to result in low frequency combustion instabilities. In this paper, firstly, RANS (Reynolds Averaged Navier Stokes) with Lagrangian stochastic parcel method for spray treatment have been solved to study combustion instabilities in a model ramjet combustor using V-gutter type flame holder. Low Reynolds k-epsilon model is used for turbulence closure, and hybrid eddy dissipation model for turbulence-chemistry interaction. The main objective is to predict dominant frequencies and various flow features of the combustor. Low-frequency, large-amplitude instabilities are observed, and the results are compared with the frequencies reported in the experiments. In the second phase of the study, the active control using secondary fuel injection has been studied, which has the potential of suppressing combustion instability without radically changing the engine design or sacrificing performance. Various fuel injection configurations have been tested in an effort to identify the key factors contributing to stable ramjet operation. Future efforts will focus on optimizing fuel placement to further improve stability limits.
- Abstract document
- Manuscript document
(absent)