• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.3
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• pp.89-95
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• 2015

Performance test was conducted for an oxidizer pump and a fuel pump for a 7 ton class rocket engine, by using water. The pumps were driven by an electric motor. The hydrodynamic performance and the suction performance were measured at flow ratio of the design and off-design conditions. Head-flow curve, efficiency-flow curve, and head-cavitation number curve were obtained. It is confirmed that the pumps can satisfy the design requirements of hydrodynamic performance in terms of the head and the efficiency. The pumps also satisfied the design requirements of suction performance.

• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.54-59
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• 2005

• Journal of Aerospace System Engineering
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• v.14 no.5
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• pp.100-106
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• 2020

Turbopumps for liquid rocket engines are exposed to various cavitation instabilities under their operating conditions. The instabilities affect the stability of the turbopumps. To make sure of the stability of the turbopump of KSLV-II, the present work examined the characteristics of the cavitation instabilities during the turbopump assembly test. In the test, the LOx pump was operated under super-synchronous rotating cavitation and attached to uneven cavitation. In the vibration analysis of the fuel pump, the characteristic frequency by the super-synchronous cavitation of the LOx pump was clearly shown.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.1099-1102
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• 2017

High frequency signals are analyzed which are measured at the inlet / outlet pipeline and pump casing during cavitation tests of the fuel pump for the liquid rocket engine. RMS values of each data are shown according to the cavitation number and compared with those of the LOx pump tests and the impact of the cavitation instability is also explored. Analogies about the cavitation number are confirmed between high frequency data of both pumps. In addition, the cavitation instability is found in all the signals and has an affect on the outlet pressure pulsation of the fuel pump.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.1093-1098
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• 2017

High frequency signals are analyzed which are measured at the inlet / outlet pipeline and pump casing during cavitation tests of the LOx pump for the liquid rocket engine. RMS values of data are shown according to the cavitation number. RMS values of the synchronous frequency, its harmonic frequencies and frequencies of cavitation instabilities are also calculated. The pressure pulsations of the inlet and outlet pipeline are affected by cavitation instabilities. 3x component is predominant in the outlet pulsation sensor since 3x component generated at the inducer is amplified at the impeller. The cavitation instability is also found at the accelerometer signal of the casing.

• Aerospace Engineering and Technology
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• v.3 no.2
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• pp.72-80
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• 2004

LOX pump is one of the sub-assemblies constructing turbopump unit. In the current study, static structural analysis on such rotating parts as impeller and inducer has been carried out. Three major factors which can affect the structural stability of the rotating parts of LOX pump, are temperature, pressure, and centrifugal force. The effect of each factor was preliminarily investigated, then the analysis under the consideration of the combined loading conditions has been carried out. The major factor that affects the structural stability was proved to be temperature. The analyses of the combined cases showed that the designed impeller and inducer had reasonable safety margins, which means that the impeller and the inducer will be stable in static structural strength. Although there was no problem in the structural strength of the impeller and the inducer, a model analysis should be followed in order to verify the interference between the rotating part and the inner surface of casing.

• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.6
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• pp.93-100
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• 2020

The turbopump of the liquid rocket engine adapts an inducer to minimize the cavitation due to the variations of the propellants supply condition. However, the inducer introduces cavitation instabilities which are well-known problems in the engine development. In this paper, operational characteristics by the cavitation instabilities are analyzed and the reliability of the engine is checked when the first stage engine of the KSLV-II is tested at the low inlet pressure conditions. The characteristic frequencies representing the cavitation instabilities of the LOx pump are clearly found in various high frequency sensor signals around the entire engine in addition to the LOx and fuel pump.

• Aerospace Engineering and Technology
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• v.8 no.1
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• pp.73-81
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• 2009

Casing leak tests using three kinds of static seals are performed by simulating test section for a 75 ton thrust class turbopump under ambient and cryogenic temperature environment. As results of application of Conical, PTFE, and C static seals to leak tests, even though they all work in normal temperature condition, only the PTFE and C static seals show good sealing performance in cryogenic condition. However, the Conical static seal fails because of the different thermal expansion rates due to the use of different materials in a LOX pump. It is found that unlike the PTFE and C static seals with sealing surfaces in axial direction, the sealing surface of the Conical static seal is in radial direction that may cause leak when the casings thermally shrink in radial direction. Especially, the C static seal reveals excellent sealing performance even for a used seal.

• Journal of the Korean Society of Propulsion Engineers
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• v.13 no.3
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• pp.20-26
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• 2009

Turbopump test for a 30-ton-thrust liquid rocket engine was carried out using real-propellant. Liquid oxygen, kerosene, cold hydrogen gas were used for the oxidizer pump, the fuel pump, and the turbine, respectively. The turbopump was reliably operated at the design and off-design conditions and the performance requirements were satisfied, which implies that the turbopump development at the engine subsystem level is successfully accomplished in the point of performance validation. This paper presents the results of a test where the turbopump was run for 75 seconds at three operating modes. In terms of performance characteristics of pumps and turbine, the results of turbopump assembly test using real-propellant showed a good agreement with those of the turbopump component tests using simulant working fluid.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.11a
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• pp.359-365
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• 2008

Turbopump test for a 30-ton-thrust liquid rocket engine was carried out using real-propellant. Liquid oxygen, kerosene, cold hydrogen gas were used for the oxidizer pump, the fuel pump, the turbine, respectively. The turbopump was run stably at the design and off-design conditions and the performance requirements were satisfied, which implies that the turbopump development at the engine subsystem level is successfully accomplished in the point of performance validation. This paper presents the results of a test where the turbopump was run for 75 seconds at three operating modes. In terms of performance characteristics of pumps and turbine, the results from turbopump assembly test using real-propellant showed a good agreement with those from the turbopump component tests using simulant working fluid.