Indian Journal of Science and Technology

Abstract

Rockets with combustion chamber would reach 3500K to 3700K. For efficiency reasons and safe design of ejectors, after-cooler is interposed between the diffuser and ejector. This process is also operated at fairly high pressure 10 to 200 bar. Due to high temperature and pressure, thermal shocks generated are prevented by spraying water particles uniformly inside the gas cooler. In this paper, the significance of water spray characteristics is studied thoroughly. The water droplet evaporated into a flow of exhaust gases with a droplet size of 15 microns diameter increases the total surface area and is about 400 m2 . The spray cooler length is suggested as 7-9 m to reduce the component of unevaporated water for optimum mass flow rate of primary fluid. Water injection velocity and pressure are varied as using number of nozzles. The injection pressure is reduced 10 times (2.0 - 2.5 bar) by increasing the number of nozzles (about 2000) in quadruple.
Keywords: Combustion chamber, Rocket, Injection pressure, Water spray