• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.85-88
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• 2010

It is essential to understand the spray characteristics of injectors for the development of liquid rocket engine systems. In this study, the image processing methods for the measurement of the spray characteristics such as spray angle, breakup length and drop size of Gas-Centered Swirl Coaxial(GCSC) injectors have been investigated. The charge-coupled device (CCD) camera with a stroboscope was used to capture the spray images. It is to be hoped that this methods could contribute to acquisition of reliable and worthwhile data for the design of injectors. Moreover, this image processing method will be verified by comparison with other experimental results.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.04a
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• pp.57-60
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• 2011

The spray characteristics according to the recess length of the GCSC injector and the change of momentum flux ratio(MFR) of the gas and the liquid have been examined through high pressure cold flow test using a high pressure chamber. The liquid in this experiment was water, and the gas was nitrogen. The spray images were taken by a back-lit strobe imaging technique. Results showed that the spray was a wide hollow cone at the lower MFR(liquid velocity was fixed) and the spray became a narrow solid cone as the MFR was increased. And the injector with short recess length produced a narrow solid cone at the higher MFR.

• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.4
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• pp.25-32
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• 2020

A numerical study on combustion instabilities in a model combustor was conducted with various momentum flux ratios. Five ratios are calculated based on an actual operating condition of rocket engine. As momentum flux ratio increases, the spreading angle on the injector outlet decreases. And, as increase of axial momentum flux, pressure fluctuation decreases inside the combustor. By using dynamic mode decomposition method, the acoustic modes inside the combustor are identified. Combustion stabilities are analyzed by comparing the damping coefficient of the 2^nd longitudinal mode.