Slide sem ttulo

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Dener Silva de Almeida , Cristiane Aparecida
Martins1, Pedro Teixeira Lacava, Aeronautical
Technology Institute, ITA, São José dos Campos,
SP, 12345-678, Brazil Corresponding author
placava_at_ita.br
INSTITUTO TECNOLÓGICO DE AERONÁUTICA

Introduction The focus of the present work is a
new configuration of Low-NOx combustor with
especial application for gas turbine. For the
concept proposed, the unfavorable combustion
conditions for NOx formation are reached through
the dynamic control of reactants mixing process
into the double-stage combustor. In the first
stage swirling air and gas fuel are injected and
a sooting flame is observed in a region close to
the flows interaction. From the first to the
second stage, the combustor diameter increases
and a pre-mixed lean combustion is stabilized
into an intense recirculation zone.
Results
Results for L//D 2, Re 40,000, ? 60 and
several global equivalence ratio.
Double-stage flame
Results for L/D 1
However, depending on the operational parameters,
some acoustic oscillations happen for the lean
combustion in the secondary chamber.
Combustor operation with acoustic instabilities
Results for L/D 2
Objective The present work is concerned about
the influence of operational parameters on the
acoustic instabilities (equivalence ratio, fuel
jet Reynolds number, swirler blades angle and
primary chamber length/diameter ratio (L/D).
Results for L/D 3
Experimental Setup
Conclusions As well as reported in the
literature, lean combustion associated with
non-homogeneous distribution of equivalence ratio
through the reaction zone causes fluctuations of
energy release which can induce pressure
fluctuations and, consequently, combustion
instabilities. However, the results presented
here showed that the instabilities attenuation or
suppression is possible by choosing suitable
values for the swirler angle, fuel jet Reynolds
number and primary chamber length/diameter ratio.