scholarly journals A sectored-one-dimensional model for simulating combustion instabilities in premix combustors

Author(s):  
Daniel Paxson
Author(s):  
Jeffery A. Lovett ◽  
Kevin T. Uznanski

Combustion instabilities are a major challenge in the development of low-emissions premixed gas turbine combustors. The development and demonstration of predictive capabilities for instabilities has progressed considerably. One of the major fundamental mechanisms demonstrated in several instances is the convection of fuel concentration fluctuations from the fuel injector to the reaction zone. A one-dimensional model has been developed which captures this mechanism coupled to solutions for standing acoustic waves. Since many real combustion systems include multiple flow paths for mixing and/or staged fuel injection, the model has been extended to include a parallel acoustic path and two fuel injection locations. Splitting of fuel between two injection positions is a common method to influence combustion dynamics toward a more operable system. A relatively simple model which only partially couples acoustics and heat release was applied to an axially staged combustor and the predictions are compared with the experimental behavior. The results from this model successfully predict the overall dynamics behavior as a function of the fuel split between the two injection locations.


1983 ◽  
Vol 4 ◽  
pp. 297-297
Author(s):  
G. Brugnot

We consider the paper by Brugnot and Pochat (1981), which describes a one-dimensional model applied to a snow avalanche. The main advance made here is the introduction of the second dimension in the runout zone. Indeed, in the channelled course, we still use the one-dimensional model, but, when the avalanche spreads before stopping, we apply a (x, y) grid on the ground and six equations have to be solved: (1) for the avalanche body, one equation for continuity and two equations for momentum conservation, and (2) at the front, one equation for continuity and two equations for momentum conservation. We suppose the front to be a mobile jump, with longitudinal velocity varying more rapidly than transverse velocity.We solve these equations by a finite difference method. This involves many topological problems, due to the actual position of the front, which is defined by its intersection with the reference grid (SI, YJ). In the near future our two directions of research will be testing the code on actual avalanches and improving it by trying to make it cheaper without impairing its accuracy.


1992 ◽  
Vol 25 (10) ◽  
pp. 2889-2896 ◽  
Author(s):  
R D Gianotti ◽  
M J Grimson ◽  
M Silbert

1993 ◽  
Vol 50 (1) ◽  
pp. 51-70 ◽  
Author(s):  
D. Zoler ◽  
S. Cuperman ◽  
J. Ashkenazy ◽  
M. Caner ◽  
Z. Kaplan

A time-dependent quasi-one-dimensional model is developed for studying high- pressure discharges in ablative capillaries used, for example, as plasma sources in electrothermal launchers. The main features of the model are (i) consideration of ablation effects in each of the continuity, momentum and energy equations; (ii) use of a non-ideal equation of state; and (iii) consideration of space- and time-dependent ionization.


2009 ◽  
Vol 25 (6) ◽  
pp. 1220-1225 ◽  
Author(s):  
Cristian H. Birzer ◽  
Con J. Doolan

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