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Numerical prediction of turbulent flame stability in premixed/prevaporized (hsct) combustors
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Winowich, Nicholas S. |
| Copyright Year | 1990 |
| Description | A numerical analysis of combustion instabilities that induce flashback in a lean, premixed, prevaporized dump combustor is performed. KIVA-II, a finite volume CFD code for the modeling of transient, multidimensional, chemically reactive flows, serves as the principal analytical tool. The experiment of Proctor and T'ien is used as a reference for developing the computational model. An experimentally derived combustion instability mechanism is presented on the basis of the observations of Proctor and T'ien and other investigators of instabilities in low speed (M less than 0.1) dump combustors. The analysis comprises two independent procedures that begin from a calculated stable flame: The first is a linear increase of the equivalence ratio and the second is the linear decrease of the inflow velocity. The objective is to observe changes in the aerothermochemical features of the flow field prior to flashback. It was found that only the linear increase of the equivalence ratio elicits a calculated flashback result. Though this result did not exhibit large scale coherent vortices in the turbulent shear layer coincident with a flame flickering mode as was observed experimentally, there were interesting acoustic effects which were resolved quite well in the calculation. A discussion of the k-e turbulence model used by KIVA-II is prompted by the absence of combustion instabilities in the model as the inflow velocity is linearly decreased. Finally, recommendations are made for further numerical analysis that may improve correlation with experimentally observed combustion instabilities. |
| File Size | 2927121 |
| Page Count | 75 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19920001943 |
| Archival Resource Key | ark:/13960/t47q3wm08 |
| Language | English |
| Publisher Date | 1990-01-01 |
| Access Restriction | Open |
| Subject Keyword | Inorganic And Physical Chemistry Flashback Dump Combustors Aerothermochemistry Computational Fluid Dynamics Flame Stability Turbulent Boundary Layer Finite Volume Method Shear Layers Combustion Physics Combustion Stability Reacting Flow Vortices Flow Distribution Premixing Flow Velocity K-epsilon Turbulence Model Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
