• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.11-15
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• 2012

A rotordynamic analysis is performed for a 7 ton class turbopump applied to the third stage LRE(Liquid Rocket Engine) of the KSLV(Korea Space Launch Vehicle). Based on the heritage of the developed experimental 30 ton class turbopump and developing 75 ton class turbopump for the KSLV first and second stage LRE, the 7 ton class turbopump is designed as an one-axis rotor turbopump. Two rotor systems comprised of one oxidizer pump assembly and the other fuel pump-turbine assembly are connected each other using a spline shaft and operating at a design speed. Through the rotordynamic analysis, it is investigated that the turbopump acquires sufficient separate margin of critical speed as a sub-critical rotor.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.29-33
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• 2009

On the basis of the development experience of a gas generator for the 30 ton-f thrust liquid rocket engine combustor a Subscale Ground Firing Test Facility was designed and fabricated for a gas generator for the 75 ton-f thrust liquid rocket engine combustor. The Subscale Ground Firing Test Facility developed is going to be used to develop 75 ton-f class gas generator. Acquired data and test technique from this facility will be used to develope the high performance liquid rocket engine combustor and the Ground Firing Test Facility. This report describes the improved Subscale Ground Firing Test Facility for 75 ton-f class gas generator and results of the cold flow test.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.928-929
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• 2017

A 75 ton class liquid rocket engine has been developed for KSLV II. Ground firing tests of the rocket engine were conducted to characterize and quantify its structural vibration under combustion testing environments. In this study, evaluation of dynamic response characteristics of the engine system was presented to verify its structural integrity and structural design during ground firing tests.

• Journal of Aerospace System Engineering
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• v.9 no.1
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• pp.1-6
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• 2015

A critical speed analysis of oxidizer pump was peformed for a 7 ton class liquid rocket engine as the third stage engine of the Korea Space Launch Vehicle II. Based on the previously developed experimental 30 ton class turbopump and presently developing 75 ton class turbopump for the first and second stage rocket engine of Korea Space Launch Vehicle II, a layout and configuration of the 7 ton class turbopump rotor assembly are determined. A ball bearing stiffness analysis and rotordynamic analysis are performed for both of the bearing unloaded condition and loaded condition. Structural flexibility of the oxidizer pump casing is also included to predict critical speeds. From the numerical analysis, it is confirmed that the rotor system acquires sufficient separate margin of critical speed as a sub-critical rotor even though decrease of critical speed due to the casing structural flexibility.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.5
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• pp.65-71
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• 2010

Performance test of the 75ton class turbopump turbine was performed. Using the measured turbine power characteristics in the wide-range operational conditions, variations of nozzle velocity ratio, total pressure loss, and relative flow angle to the pressure ratios and rotational speeds are quantified. Efficiency and nozzle exit pressure behavior was also investigated and compared with 30ton turbopump turbine data. A rotor blade was redesigned based on the test results and CFD analysis.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.38-44
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• 2010

Performance test of the 75ton class turbopump turbine was performed. Through the turbine power measurement in the wide-range operational conditions, velocity ratio, total pressure loss, and relative flow angle characteristics was quantified. Efficiency and nozzle exit pressure behavior was also investigated and compared with 30ton turbopump turbine data. A rotor blade was redesigned based on the test results and CFD analysis.

• Tribology and Lubricants
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• v.25 no.3
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• pp.187-191
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• 2009

A leakage performance test and an endurance performance test of a 75 ton class turbopump mechanical face seal are performed using water under high speed and high temperature environment. A prototype mechanical face seal is manufactured for the purpose of sealing of fuel between a fuel pump and turbine. By simulating operating condition experimentally, the leakage rate and seal carbon wear rate are obtained to evaluate the performance of the prototype mechanical face seal. The test results show the acceptable leakage performance and reasonable wear tendency as well.

• Journal of Aerospace System Engineering
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• v.7 no.4
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• pp.49-54
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• 2013

A turbopump for a 75 ton class liquid rocket engine was tested at full speed for 20 seconds using model fluid. Liquid nitrogen is used for the oxidizer pump, water for the fuel pump, and hot gas for the turbine. The non-cavitating head of pump from the turbopump assembly test showed a good agreement with that from the pump component test. The relative difference of turbine efficiency between the turbopump assembly test and the turbine component test was 0.3% only. Suction performance from the turbopump assembly test was higher than that of pump component test, which resulted from the thermodynamic effect of cavitation.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.608-612
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• 2009

Technology demonstration models(TDM) of a 75-$ton_f$ liquid rocket engine(LRE) thrust chamber were manufactured on the basis of development technologies of 30-$ton_f$ LRE. It was confirmed that some machining and welding technologies which were aimed to be verified through the manufacturing of demonstration models could be applied to the thrust chamber 75-$ton_f$-class. New designed mixing head part was manufactured by means of new process. The manufacturing process and technologies established through TDM's will improve the reliability of manufacturing process of large LRE thrust chamber.

• Aerospace Engineering and Technology
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• v.9 no.2
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• pp.8-13
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• 2010

An effective control of the axial thrust of a turbopump is one of the critical issues for obtaining its operational stability. Axial thrusts of the fuel pump for the 75-ton class rocket engine under development were measured with water as a test propellant at a room temperature. According to the test results, the axial thrust of the fuel pump seemed to satisfy the axial force condition of its bearing. Also, the thrust was increased as a whole when the flowrate of the pump was decreased. Furthermore it was found that the thrust and the leakage flowate were modified when the gaps between the floating ring seals and the impeller were changed.