• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.159-162
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• 2011

The hot-firing tests of a subscale gas generator were successfully performed to investigate the effect of injector shape variation on its discharge coefficient. The test results showed that discharge coefficients of fuel and liquid oxygen injectors remained nearly constant irrespective of the mixture ratio or the chamber pressure. In all experimental conditions, the combustion instability was not observed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.04a
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• pp.73-76
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• 2011

The hot-firing tests of a subscale gas generator were successfully performed to investigate the effect of injector shape variation on discharge coefficients. The test results showed that discharge coefficients of fuel and liquid oxygen injectors remained nearly constant irrespective of variations of a mixture ratio and a chamber pressure. Especially, the discharge coefficient of the liquid oxygen injector was largely increased compared to the previous works.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.472-474
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• 2012

The hot-firing tests of a subscale gas generator were successfully performed to investigate the effect of injector shape variation on its discharge coefficient. The test results showed that discharge coefficient of liquid oxygen injectors was enhanced significantly. However, the combustion instability of low-frequency fluctuation occurred at low and design pressure conditions.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.877-880
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• 2011

A coaxial swirl/shear injector using GCH4/LOx as propellants was degisned and manufactured. Flow analysis by Fluent was performed to decide the number of orifice and the rear shapes of inlet orifice etc. Flow rate of the injector was measured according to differential pressure and uniformity of injector's spray pattern was confirmed by a patternator. The results showed that the difference of flow rate was around 10% and the spray angle of oxidizer was $66^{\circ}$.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.658-661
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• 2011

A coaxial swirl/shear injector using GCH4/LOx as propellants was degisned and manufactured. Flow analysis by Fluent was performed to decide the number of orifice and the rear shapes of inlet orifice etc. Flow rate of the injector was measured according to differential pressure and uniformity of injector's spray pattern was confirmed by a patternator. The results showed that the difference of flow rate was around 10% and the spray angle of oxidizer was $66^{\circ}$.

• 한국전산유체공학회:학술대회논문집
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• 2006.10a
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• pp.7-8
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• 2006

The governing equations for high-speed lateral atomizing injector nozzle flow based on the LES-VOF model in conjunction with the CSF model are presented, and then an integrated parallel computation are performed to clarify the detailed atomization process of a high speed nozzle flow and to acquire data which is difficult to confirm by experiment such as atomization length, liquid core shapes, droplets size distributions, spray angle and droplets velocity profiles. According to the present analysis, it is found that the atomization rate and the droplets-gas two-phase flow characteristics are controlled by the turbulence perturbation upstream of the injector nozzle, hydrodynamic instabilities at the gas-liquid interface, shear stresses between liquid core and periphery of the jet. Furthermore, stable and a high-resolution computation can be attained in the high density ratio (pl/ pg = 554) conditions conditions by using our numerical method.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.4
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• pp.99-106
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• 2010

A piezo-driven injector was applied with a purpose to evaluate the effect of induced voltage on spray characteristics. For this, injection rate, macroscopic imaging, ambient gas entrainment and particle sizing were carried out. It was shown that initial slope of injection rate was steeper as induced voltage increased, while slope of injection rate became mostly constant with fully opened needle. From macroscopoic imaging, longer spray tip penetration was produced with higher induced voltage. Moreover, wider spray angle was detected in the early stage of spray development, when higher induced voltage was applied. Ambient air entrainment rate was increased and particle size was reduced with higher induced voltage.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.13-18
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• 2010

This study aim to investigate the internal mixing flow characteristics by recess length of swirl coaxial injector for gas generator has propellant of Kerosene-LOx. Recess length is a very important element, have influence in spray stability and LOx post damage. The influence of recess length was analyzed by visualizing internal flow and measuring liquid film thickness and manifold pressures. Also, frequency characteristics were analyzed by liquid film thickness measurement with mixing time.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.1
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• pp.174-185
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• 1997

The performance of the solenoid actuated hydrogen injector and the capacitive peak-hold type driving circuit was predicted through the modeling of the injector and the driving circuit the modeling was composed of the driving circuit, the solenoid, the moving parts of the injector, and the hydrogen injection system. The performance of the injector through the modeling was compared with the results of the solenoid and injector rig tests, and those were consistent with each other. Through the prediction of the injector performance, the effects of the components such as electrical resistor, capacitor, and injector spring are easily known to the injector performance required.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.560-564
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• 2004

The optimal design and combustion analysis of the gas generator for Liquid Rocket Engine (LRE) were performed. A fuel-rich gas generator in open cycle turbopump system was designed for 10ton$_{f}$ in thrust with RP-1/Lox propellant. The optimal design was done for maximizing specific impulse of main combustion chamber with constraints of combustion temperature and power matching required by turbopump system. Design variables were selected as total mass flow rate to gas generator, O/F ratio in gas generator, turbine injection angle, partial admission ratio, and turbine rotational speed. Results of optimal design show the dimension of length, diameter, and contraction ratio of gas generator. Also, the combustion test was conducted to evaluate the performance of injector and combustion chamber. And the effect of the turbulence ring was investigated on the mixing enhancement in the chamber.r.