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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
December, 17-20, 2021, IIT Madras, Chennai, India

Comparative Combustion Performance of Swirl Coaxial Injectors

Get access (open in a dialog) DOI: 10.1615/IHMTC-2021.1010
pages 679-683

Abstract

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.