Publisher : The Korean Society for Aeronautical & Space Sciences
DOI : 10.5139/IJASS.2014.15.4.444
Title & Authors
Experimental study on the spray characteristics of a dual-manifold liquid-centered swirl coaxial injector Lee, Ingyu; Yoon, Jungsoo; Park, Gujeong; Yoon, Youngbin;
A throttleable rocket engine enables operational possibilities such as the docking of spacecraft, maneuvering in a certain orbit and landing on a planet's surface, altitude control, and entrance to atmosphere-less planets. Thus, throttling methods have long been researched. However, dual-manifold injectors, which represent one throttling method, have been investigated less than others. In this study, dual-manifold and single-manifold injectors were compared to determine the characteristics of dual-manifold injectors. Also, the effects of gas injection were investigated with various F/O ratios. To investigate the characteristics, mass flow rate, spray pattern, spray angle, and droplet size were measured. The spray angle and droplet size were captured by indirect photography. About 30 images were taken to assess the spray patterns and spray angle. Also, 700 images were analyzed to understand the droplet distribution and targeting area, moving to the right from the centerline with 1.11-cm intervals. The droplet size was obtained from an image processing procedure. From the results, the spray angle showed two transition regions, due to swirl momentum in the swirl chamber regardless of the F/O ratio. The droplet size showed similar trends in both dual-manifold and single-manifold injectors except in the low mass flow rate region. In the case of the dual- manifold injector, the spray cone was not fully developed in the low mass flow rate region due to low angular momentum in the swirl chamber.
throttleable injector;dual manifold;coaxial injector;Sauter mean diameter(SMD);spray angle;
G. A. Dressler, "Summary of Deep Throttling Rocket Engine with Emphasis on Apollo LMDE", 42nd AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, 9-12 July 2006.
Matthew J. Casiano, James R. Hulka, and Vigor Yang, "Liquid-Propellant Rocket Engine Throttling: A Comprehensive Review", Journal of Propulsion and Power, Vol. 26, No. 5, September-October 2010.
Y. Hardalupas and J. H. Whitelar, "Characteristics of Sprays Produced by Coaxial Airblast Atomizers", Journal of Propulsion and Power, Vol. 10, No. 4, July-Aug 1994.
J. C. Lasheras and E. J. Hopfinger, "Liquid Jet Instability and Atomization in A Coaxial Gas Stream", Annual Review of Fluid Mechanics, Vol. 32, 2000, pp. 275-308.
J. H. Im, Spray Characteristics of Gas-Liquid Swirl Coaxial Injectors for Liquid Rocket Engines, Ph. D Thesis, 2010.
J. Y. Kim, J. H. Chu and S. Y. Lee, "Improvement of Pattern Recognition Algorithm for Drop Size Measurement", Atomization and Sprays, Vol 9, 1999, pp.313-329.
Y. J. Choo and B. S. Kang, "Measurement of Sizes and Velocities of Spray Droplets by Image Processing Method", ILASS-Korea, 2002, pp.121-128.
V. G. Bazarov, "Throttleable Liquid Propellant Engines Swirl Injectors for Deep Smooth Thrust Variations", 30th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, 27-29 June 1994.
J. S. Yoon, Characteristics of Throttelabe Liquid Rocket Injector with Dual Manifold, MS Thesis, 2010
Arthur H. Lefevbre, Atomization and Sprays, Hemisphere Publishing Corporation, 1989.
M. Zaller and M. Klem, "Shear Coaxial Injector Spray Characteristics", Liquid Rocket Engine Combustion Instability, AIAA, pp.191-213.