• Journal of the Korean Society of Propulsion Engineers
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• v.11 no.4
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• pp.59-66
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• 2007

In this paper, experimental investigation results of the effect of partial admission ratio on the performance of axial turbine was presented. A supersonic impulse turbine of gas generator cycle liquid rocket engine turbopump was used for the test. for experimental purpose, a nozzle block, in which total 14 number of axi-symmetric convergent-divergent nozzles are arranged circumferentially, was designed and manufactured. Partial admission ratio was controlled by changing the number of active nozzles. High pressure air was used as working medium for the test. The experimental result revealed that the performance of the supersonic impulse turbine does not much affected by the partial admission ratio for supersonic impulse turbine.

• Aerospace Engineering and Technology
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• v.6 no.2
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• pp.197-204
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• 2007

Effect of rotor tip geometry on the performance of supersonic impulse turbine was investigated experimentally. Using the shrouded supersonic impulse turbine of the 30ton class liquid rocket engine turbopump as a base model, the measured performance of de-shrouded rotor was compared. The effect of nozzle-rotor overlap also has been investigated. It has been found that the magnitude of turbine efficiency is largely affected by the existence of the rotor shroud. However, measured efficiency sensitivity of the de-shrouded supersonic impulse turbine with respect to turbine tip clearance was relatively smaller than that of high performance reaction turbine. It also has been found that there exists nozzle-rotor overlap value which results optimum efficiency in supersonic impulse turbine.

• The KSFM Journal of Fluid Machinery
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• v.8 no.6 s.33
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• pp.26-32
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• 2005

1.6 MW class supersonic partial admission impulse turbine has been designed and tested in Korea Aerospace Research Institute for the liquid rocket engine application. The test has been performed using a high pressure air source facility in KARI. For the turbine power absorption, a hydraulic dynamometer has been used. Appropriate similarity relations are used for the determination of test condition. Various settings of turbine pressure ratio and rotational speed are tested to investigate global turbine characteristics. From measured data, parameters related to the turbine design are derived and validated.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.125-131
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• 2004

1.6 MW class supersonic partial admission impulse turbine has been designed and tested in Korea Aerospace Research Institute for the liquid rocket engine application. The test has been performed using a high pressure air source facility in KARI. For the turbine power absorption, a hydraulic dynamometer is used. Appropriate similarity relations are used for the determination of test condition. Various settings of turbine pressure ratio and rotational speed are tested to investigate global turbine characteristics. From measured data, Parameters related to the turbine design are derived and validated.

• Journal of the Korean Society of Propulsion Engineers
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• v.13 no.5
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• pp.7-14
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• 2009

A methodology of design performance estimation for the supersonic impulse turbine was investigated. Relations of similarity condition and test nozzle area ratio were derived. Comparison of efficiencies between the turbines with real nozzle and test nozzle are made numerically and experimentally. The CFD results and test result confirmed that the turbine with test nozzle was able to predict real turbine performance. In addition, design performance of the supersonic impulse turbine also could be estimated using real nozzle in air-medium test. In this case, design efficiency was found at the pressure-ratio and velocity-ratio of similarity condition of test nozzle.

• Journal of computational fluids engineering
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• v.10 no.2
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• pp.54-59
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• 2005

For the improvement of aerodynamic performance of the turbine blade in a turbopump for the liquid rocket engine, the optimization of turbine profile shape has been studied. The turbine in a turbopump in this study is a partial admission of impulse type, which has twelve nozzles and supersonic inflow. Due to the separated nozzles and supersonic expansion, the flow field becomes complicate and shows oblique shocks and flow separation. To increase the blade power, redesign ol the blade shape using CFD and optimization methods was attempted. The turbine cascade shape was represented by four design parameters. For optimization, a genetic algorithm based upon non-gradient search hue been selected as an optimizer. As a result, the final blade has about 4 percent more blade power than the initial shape.

• International Journal of Aerospace System Engineering
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• v.3 no.1
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• pp.25-29
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• 2016

This paper highlights the performance of an impulse turbine which is a part of turbopump in a liquid rocket first stage engine. The turbopump, currently under development at Korea Aerospace Research Institute, has an impulse type turbine with 12 nozzles and a single rotor. The impulse turbine can archive high specific power with the low gas flow rates. The supersonic impulse turbine with a single rotor can make a simple structure. High-pressure gases are converted into the dynamic energy with flows through the 12 nozzles and drive the rotor to make the power for the pumps. The turbine test was performed in the high-pressured turbine test facility with air gas instead of burned gas. A hydraulic dynamometer was used to absorb the power from the turbine and control the rotational speed and torque. The test points were at several pressure ratios with 7 different rotational speeds. Results showed the efficiency was highest at the design pressure ratio. The efficiency was insensitive to the pressure ratio variation than the rotational speed. It was a typical characteristic in an impulse turbine.

• 한국전산유체공학회:학술대회논문집
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• 2005.04a
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• pp.191-196
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• 2005

For the improvement of aerodynamic performance of the turbine blade in a turbopump for the liquid rocket engine, the optimization of turbine profile shape has been studied. The turbine in a turbopump in this study is a partial admission of impulse type, which has twelve nozzles and supersonic inflow. Due to the separated nozzles and supersonic expansion, the flow field becomes complicates and shows oblique shocks and flow separation. To increase the blade power, redesign of the blade shape using CFD and optimization method was attempted. The turbine cascade shape was represented by four design parameters. For optimization, genetic algorithm based upon non-gradient search has been selected as a optimizer. As a result, the final blade has about 4 percent more blade power than the initial shape.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.43-48
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• 2010

Present study was conducted numerical analysis for velocity compound supersonic impulse turbine with the rotor overlaps, and the performance characteristics were analyzed through the numerical results. Tip overlap was more effective than hub overlap through the analysis. a case, overlap applied the hub and tip of the rotor, has the largest improvement for the turbine performance in parametric study cases. In case of overlap for the 2nd stage rotor, however, improvement of the turbine performance was not visibly large. Because, power generated in the 2nd stage was 22~23% of whole generated turbine power.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.11a
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• pp.117-121
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• 2008

The effect of tip clearance on the performance of a supersonic impulse turbine was investigated experimentally. Test was performed using high pressure air in wide ranges of pressure ratio and rotational speeds. Test revealed that efficiency gradient of the subject turbine at a reference test point was a very low value of 0.05. Turbine efficiency was varied non-linearly with respect to tip clearance. It has been found that efficiency gradient is proportional to the cube of rotational speed at a fixed turbine pressure ratio. It also has been found that efficiency gradient shows its minimum at a reference test pressure ratio irrespective of rotational speeds.