• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.11a
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• pp.94-97
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• 2008

As the partial admission turbine has a intrinsically unsteady and three dimensional flow region, numerical calculation time of these study has been too long time. The numerical analysis for gas temperature of turbine blade surface has been performed to investigate development of temperature with various pyro start pressure. Computations have been carried out several turbine rotational speeds in the range from 0 to 16000 rpm and inlet conditions with 1423K, 7.2MPa. As a result, the more rotational speed and pyro starter pressure of turbine increased, the more turbine blade's temperature decreased. It is also found that flow field of turbine blade inlet area at pyro starter pressure of 5.75MPa and rotational speed of 12100 rpm formed surface temperature uniformly.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.1
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• pp.35-41
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• 2013

Torque characteristics of a turbopump turbine was analyzed using the turbine performance test result. Specific torque of the subject turbine could be expressed as a linear function of corrected rotor speed at a fixed pressure ratio and it has been confirmed by the test result. It also found that corrected rotor speed-specific torque characteristics does not change anymore if the turbine pressure ratio is set bigger than a certain value. Using the turbine torque characteristics and pyro-starter performance test results, rotational speed development behavior of the turbopump was predicted. Prediction revealed that the lap time reaching 50% of turbopump design speed is less than 0.7 second. Effect of the thermal loss between pyro-starter and turbopump was negligible.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.4-10
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• 2012

Torque characteristics of a 75-tonf turbopump turbine was analyzed using the turbine performance test result. Specific torque of the subject turbine could be expressed as a linear function of corrected rotor speed at a fixed pressure ratio and it has been confirmed by the test result. It also found that corrected rotor speed-specific torque characteristics does not change anymore if the turbine pressure ratio is set bigger than a certain value. Using the turbine torque characteristics and pyro-starter performance test results, rotational speed development behavior of the turbopump was predicted. Prediction revealed that the lap time reaching 50% of turbopump design speed is less than 0.7 second. Effect of the thermal loss between pyro-starter and turbopump was negligible.

• Journal of the Korean Society of Propulsion Engineers
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• v.21 no.3
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• pp.18-24
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• 2017

Appropriate selection of the starter is essential for successful starting of the gas-turbine engine. Thus, aerodynamic drag during starting phase should be analyzed to assess the feasibility of the starter. In this paper, aerodynamic drag is modeled based on the speed profile from the engine coast down test, and it is scaled with respect to the target engine by comparing the compressor load. Afterward, the govern equation of the starting phase is developed with the torque model of the starter, and the design scheme to select the feasible starter will be finally suggested. The proposed model of starting phase will be useful to perform a preliminary design of the starting system of the gas-turbine engine.

• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.5
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• pp.1-9
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• 2021

As part of the commercialization research of small gas turbine engines, starting and normal operation control logic research of small gas turbine engine was conducted. It was investigated how the igniter, starting motor and fuel pump/valve are controlled during the ignition and normal operation process and it was applied to the prototype engine control unit(ECU) of the small gas turbine engine for commercialization research. Based on the ground test results, an ECU for flight test is being developed, and after completion of the development, an altitude test will be performed through an altitude test facility of Korea Aerospace Research Institute.

• Journal of the Korean Society of Propulsion Engineers
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• v.12 no.4
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• pp.48-55
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• 2008

In this paper, numerical analysis of the surface gas temperature on turbine blades has been performed to investigate the temperature profiles characteristics of a partial admission supersonic turbine driven by high temperature and pressure gas of pyro-starter with two different types of turbine blade edge shape. In order to examine the surface gas temperature on turbine blades at initial starting, computations tlave been carried out at several turbine rotational speeds in the range of $0{\sim}10,000$ rpm for each type of turbine edge shape. "Sharp" edge and "Round" edge types were taken as the turbine edge shape factor. As turbine rotational speed increased, the average temperature of turbine blades was further decreased. It was also found that the surface temperature of turbine blades with a sharp edge was lower than round-type edge turbine blades.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.3
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• pp.1-8
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• 2016

It was examined that start-up characteristics of a staged combustion cycle engine powerpack. Among various parameters, valve opening time was considered as a main factor affecting the start-up characteristics. Using monte-carlo method, characteristics variation was analyzed when the valve opening time deviates from the nominal value. As a result, the main fuel valve opening time and the start turbine ending time were significant associated with the startup characteristics. When separating main fuel valve opening time and start turbine stop time, main fuel valve opening time was an important factor. For stable operation, the main fuel valve opening time must be set one second before after driving the start turbine. Likewise, it was confirmed that the startup analysis can suggest an appropriate startup sequence for a stable startup.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.985-987
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• 2011

This paper includes a development of a starting time prediction model for a derivative engine. For this derivative engine design, a new map expansion method, Modified Pump Scaling Law(MPS), has been applied and expand the maps to sub-idle range. From loss characteristics of the reference engine, loss models for the derivative engine have been developed considering different pressure, temperature, and engine configurations. Starting time predictions of the derivative engine shows preferable results comparing test results.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.821-826
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• 2011

The turbopump+gas generator (TP+GG) coupled test for the liquid rocket engine development was performed. By comparing the results of a engine startup transient analysis with this test results, the verification of the analysis model was performed. From this, as to the analysis of the engine startup, the method calculating the pressure ratio of the turbine during the initial stage of startup was improved. And a fact that the transient heat transfer phenomenon between the working fluid and the solid parts of turbine effects to the calculation of turbine pressure ratio and consequentially to the startup analysis was revealed.

• The KSFM Journal of Fluid Machinery
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• v.15 no.4
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• pp.27-32
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• 2012

Gas turbines for an aircraft have the start and restart capabilities within their flight envelop. It is an important item for engine qualification and substantiated with the test. Experimental investigations were carried out to find the relation between the corrected torque and the corrected rotating speed of an air turbine starter in this study. A dedicated air supply system for the air turbine starter and a special device to measure the torque and the rotating speed of the air turbine starter were developed and installed at the altitude engine test facility in Korea Aerospace Research Institute. Experimental results show that the relations between the corrected torque and the corrected rotating speed of the air turbine starter are linear and the inlet temperature and pressure conditions for the air turbine starter were found out to provide minimum required torque for the engine qualification test at various altitude. The start and restart tests for the currently developing engine were successfully performed using this experimental results.