Study on atomization and combustion characteristics of -- Fang, Xin-xin; Shen, Chi-bing -- Acta Astronautica, 136, pages 369-379, 2017 jul -- Elsevier -- 10.1016_j.actaastro.2017.03

X.-x. Fang, C.-b. Shen Acta Astronautica 136 (2017) 369–379
Fig. 15. Streamline for different h o.
brought into the center of the combustor. Finally, the high-temperature
combustion products lead to more rapid spray mixing.
Fig. 16 shows the combustor pressure for different h o . The
combustor pressure decreases and the trend becomes flat along with
increase of h o , and decrease of the size of the recirculation zone C is
responsible for that. Thus, when designing pintle injectors, the velocity
of LOX could not be chosen too small or the gas-liquid momentum
ratio could not be chosen too big.
Fig. 17 shows the temperature field for different h o . The gas
temperature near the pintle tip decreases along with increase of h o .
When h o is 0.06 mm there is a strong temperature gradient along the
axis of the combustor. The reasons are the same as that in Section 5.1.
The recirculation zones C in Fig. 15 has great influences on the
combustion stability of the pintle engines as discussed before. The size
of the recirculation zone C is bigger and more high-temperature gas is
entrained into it when h o is small.
Fig. 16. Combustor pressure for different h o.
(see in Fig. 13). As for recirculation zone C, it has great positive
influences on the combustion stability of the pintle engines. There are
three reasons for this [42]. Firstly, it provides a continuous heat source
for ignition purpose. Secondly, it enables the combustion zone to be
5.3. Influence of L* on combustion performance
Four different parameters were selected, which are 0.8 m, 1.0 m,
1.2 m and 1.4 m to study influences of L*. The diameter of the
combustor keeps constant, while the lengths are 180 mm, 220 mm,
260 mm and 300 mm respectively (see in Table 2). For different L*, the
size of the grids keeps unchanged. Thus, bigger L* has greater amount
Fig. 17. Temperature field for different h o.
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