ISSN Online: 2688-7231
ISBN Online: 978-1-56700-524-0
Proceedings of the 26thNational and 4th International ISHMT-ASTFE Heat and Mass Transfer Conference December 17-20, 2021, IIT Madras, Chennai-600036, Tamil Nadu, India
Comparative Combustion Performance of Swirl Coaxial Injectors
摘要
In the current study, the performance of three variants of
the coaxial injector is assessed. The first one is a liquid-centre liquid-swirl coaxial injector where liquid propellant flows in the central passage with swirl and gaseous propellant flows in the annular passage without swirl (LCLSI). The second variant has liquid flowing in the central passage with swirl and coswirling gas flowing in the annular passage (LCCOSI). The
final variant consists of liquid flowing in the central passage
with swirl and counter swirling gas flowing in the annular
passage (LCCNSI). The injectors were designed using typical
liquid-propellant rocket engine parameters. The propellant
combination used was gaseous oxygen and Isrosene (refined
kerosene used as rocket fuel). A water-cooled combustor was
designed and realized to carry out the performance evaluation
study. The visual appearance of the plume obtained during the
tests was analyzed and a qualitative comparison is presented in
this study. The injection pressures, chamber pressure, mass
flow rates were measured during the experiments. Based on
this, the mixture ratio (ratio of oxidizer mass flow rate to fuel mass flow rate) and the experimental characteristic velocity were obtained. The experimental characteristic velocity is normalized by the theoretical characteristic velocity to obtain the characteristic velocity efficiency. The characteristic velocity efficiency indicates the performance of the injector. The characteristic velocity efficiency for all three injectors was evaluated and compared. The LCLSI injector showed the highest performance of all the injector variants studied.