• Bulletin of the Korean Space Science Society
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• 2004.04a
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• pp.71-71
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• 2004

KSLV-I 추진기관 기체공급계는 상부의 산화제 탱크로부터 나온 산화제 주배관이 하부의 연료탱크를 관통하여 엔진공급계로 이어지도록 구성되어 있다. 연료탱크에는 산화제 배관의 관통을 위한 tunnel이 구성되어 있으며 배관과 tunnel은 일정한 간격을 유지하게 된다. 배관과 연료탱크 사이의 열전달을 줄이기 위하여 산화제 배관에 단열재를 적용할 수 있으나, 이 경우 배관의 운송, 조립시에 handling이 힘들게 되고, 특히 발사체에 조립된 후에 발생하는 단열재의 파손 및 성능감소에 대한 유지보수가 불가능하다. (중략)

• Aerospace Engineering and Technology
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• v.10 no.1
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• pp.54-62
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• 2011

The pressurant mass required for propellant tank pressurization with operating condition variation was estimated by using the numerical model already developed for this purpose. The model was applied to the concept design results of KSLV-II first stage oxygen tank. The supplied pressurant temperature, oxygen volumetric flow rate, and the ratio of length to diameter of the tank were selected as variables. The required pressurant mass and mass flow rate, collapse factor, ullage temperature distribution were predicted, and the results showed that the pressurant temperature had the largest effect on the amount of the required pressurant mass. The pressurizing efficiency of the propellant tank was calculated through analyzing energy distribution in the ullage. It was found that the gas-to-wall heat transfer in the ullage was dominant, and much of the pressurant energy was lost to tank wall heating.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.854-856
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• 2011

A vent relief valve for oxidizer tank has been designed for liquid propellant feeding system of the space launch vehicle. The vent relief valve ensures oxidizer tank ventilation during filling and its protection from overpressure after filling. Tank ventilation during filling is ensured by vent valve and tank protection is ensured by combined operation of relief valve and vent valve. Numerical analysis predicted that pneumatic behavior and dynamic characteristics met the valve requirements. After manufacturing the prototype model, we have been conducting the tests to evaluate the performance of the vent relief valve.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.1171-1175
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• 2017

Cryogenic helium gas is used as the pressurant for the oxidizer pressurization of DR(Damper Receiver) sphere in the PSD(Pogo Suppression Device) system and liquid oxygen is used as the oxidizer for the propellant in Korea Space Launch Vehicle-II. The helium gas is stored in pressurant cylinders inside the cryogenic liquid oxygen tank and liquid oxygen is stored in the oxidizer tank. In this study, the performance test of PSD liquid oxygen drain valve for KSLV-II was considered.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.11a
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• pp.389-392
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• 2007

The study focused on the flow-supply characteristics of the liquid oxidizer $N_2O$ reserved in a tank without any pressurization devices. It was taken accounted that the change of material properties to temperature in the oxidizer tank and the discharge coefficients of both liquid and gas for more precise prediction of the supply mass-flow rate of $N_2O$ oxidizer. To validate the prediction model derived in the study, the experiments were conducted and compare with the theoretical results.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.1051-1053
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• 2017

We have designed the vent relief valve to set bi-level safety pressure for oxidizer tank. The minimum cavity volume was calculated to reduce the pressure deviation, and the valve operation characteristics was analyzed by using modeling. We have a plan to manufacture the validation model based on the analysis results.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.273-277
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• 2009

An oxidizer tunnel-type pipe, which shall transport oxidizer from an oxidizer tank to a turbo-pump of an engine, studied is installed through a fuel tank located under an oxidizer tank. A tunnel-type pipe can save weight compared to a detour-type pipe, however may vary the temperature of fuel stored in a fuel tank because of a broad heat transfer area. Hence in this study the characteristics of main oxidizer pipe and thermal propagation from oxidizer to a fuel tank are monitored by a cryogenic performance test with a tunnel-type pipe. In addition, the possibility of adaptation of an oxidizer tunnel-type pipe to launcher system is also analyzed.

• Bulletin of the Korean Space Science Society
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• 2004.04a
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• pp.74-74
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• 2004

액체추진제를 사용하는 위성 발사체의 경우 추진제탱크에 저장된 추진제를 추력을 발생하는 연소실에 공급하기 위하여 헬륨 등의 가압제를 사용한다. 본 연구에서는 액체추진제 로켓엔진의 산화제인 극저온의 액체산소를 저장하고 있는 탱크 내부에 설치된 별도의 탱크에 저장된 극저온/고압의 헬륨을 고온으로 열팽창 시켜 추진제 탱크로 재유입하여 추진제를 가압하는 시스템에 사용되는 가압제 열팽창용 열교환기의 개발을 위한 기초 설계를 수행하였다. (중략)

• Aerospace Engineering and Technology
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• v.9 no.2
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• pp.168-175
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• 2010

During feeding oxidizer to the engine, vortices are occurred at lower dome of oxidizer tank inside by various working environments and external forces for liquid propellant feeding system of space launch vehicle. To eliminate the vortices or swirls Anti-Vortex Devices(AVD) shall be installed at inside lower oxidizer tank. Using the numerical analysis, we have confirmed the performance of AVD and analyzed the mass flow rate by feeding time and magnitudes of swirls on the free surface of oxidizer or exit surface according to the AVD number and length. Then we could derive the optimal design of the AVD number and length.

• Journal of Aerospace System Engineering
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• v.15 no.5
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• pp.98-105
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• 2021

This study presented the results of the static load tests conducted to verify the structural robustness of the composite oxidant tank for a space launch vehicle. First, we introduced the test equipment used in the static load test of the composite oxidant tank, and then described the test requirements that the composite oxidant tank must satisfy. In addition, we presented a test set-up diagram consisting of the static load test fixture, hydraulic pressure, control equipment, and data acquisition equipment, and the load profile of the static load test of the composite oxidant tank consisting of shear, equivalent compression, bending, and combination tests. As a result of load control, we verified the reliability of this test by showing the errors between the input load and the feedback load in each channel according to the increase of the test load, and the feedback error between the channel A and channel B of load cell in each load actuator. As a result of the static load test, the load of the actuator was properly controlled within the allowable error range in each test, and we found that the test specimen did not cause damage or buckling that causes significant structural defects in the required load.