On the Formation of Nitrogen Oxides During the Combustion of ...

3 Experiments on Droplet Array Combustion
are arranged bottom-up [195–197]. Within the framework of a cooperation,
the Japan Aerospace Exploration Agency (JAXA) had the main responsibility
in developing and integrating the “Japanese Combustion Module” (JCM),
with the DCU being the experiment core section. The remaining devices of
the JCM, including mechanical interfaces, electronic components, and outer
structure are not shown here for the sake of clarity. Height and weight of
the JCM are 1290 mm and 103 kg, respectively. The DCU itself is built of six
platforms (Fig. 3.2, B - G), supported by six props each, with a total height
of 813mm and a platforms diameter of 372 mm (see also Tab. C.1). A vacuum
dome covers the DCU in order to keep it pressurized. Electronic control
devices and batteries are mounted outside of this pressurized dome, below
the experiment deck. The modular design of the DCU facilitates adjustment
and modification work, as is necessary, for instance, with the droplet generation
setup and the exhaust gas sampling system (EGS). The DCU consists of
droplet array generation and lifting devices, combustion chamber, air supply
and exhaust system, observation system, exhaust gas sampling system, and
main structure [208, 296]. Figure 3.3 gives a close-up view of the droplet array
lifting devices that are installed on the second and third platform of the DCU
and are used to move a newly generated droplet array into the combustion
chamber (cf. Fig. 3.2, C and D).
The outlined combustion facility was used for cooperative experiments by the
“Droplets Combustion Dynamics Research Working Group” of JAXA and the
research team on “Combustion Properties of Partially Premixed Spray Systems”,
which was financially supported by the European Space Agency (ESA).
The collaborative study addressed the effects of partial pre-vaporization of
fuel droplets on subsequent flame propagation and exhaust gas formation,
being the research foci of the two respective partners. Thereupon, the
scientific experiment was entitled “PHOENIX” (Investigation of Partial Pre-
Vaporization Effects in High Temperature on Evolution of Droplet Array Combustion
and Nitrogen Oxides Formation). Its scientific requirements were formulated
by the two research groups, within which the European part was executed
by the author of this thesis. Since the concept of the combustion facility
is based on a Japanese apparatus for drop shaft experiments, the setup needed
to be retrofit for exhaust gas sampling and customized to its operation during
sounding rocket flight on the TEXUS system [208, 293, 294, 296].
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