• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.1
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• pp.9-19
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• 2017

In this study, stator shroud injection in a single-stage transonic axial compressor is proposed. A parametric study of the effect of stator shroud injection on aerodynamic performances was conducted using the three-dimensional Reynolds-averaged Navier-Stokes equations. The curvature, length, width, and circumferential angle of the stator shroud injector and the air injection mass flow rate were selected as the test parameters. The results of the parametric study show that the aerodynamic performances of the single-stage transonic axial compressor were improved by stator shroud injection. The aerodynamic performances were the most sensitive to the injection mass flow rate. Further, the total pressure ratio and adiabatic efficiency were the maximum when the ratio of circumferential angle was 10％.

• Journal of the Korean Society of Propulsion Engineers
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• v.11 no.4
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• pp.10-18
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• 2007

A tested micro axial-type turbine consists of two stages and its mean radius of rotor flow passage is 8.4 mm. This turbine could be applied to a driver of micro power system, and its rotational speed in the unloaded state reaches to 100,000 RPM. The performance of this system is sensitive depending on the blade angles of the rotor and stator because it is operated in a low partial admission rate, so a performance test is conducted through measuring the specific output power and the net specific output torque with various blade angles on the nozzle, stator and rotor. The experimental results show that the net specific output torque is varied by 15% by changing the rotor blade angle, and the optimal incidence angle is about $10.3^{\circ}$.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.7
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• pp.831-840
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• 1999

In this work, an aerothermodynamic calculation model for cooled axial flow turbine blades with trailing edge ejection is suggested and a mean line performance analysis of a turbine stage with nozzle cooling is carried out. A unique model regarding the interaction between coolant and main gas is proposed, while existing correlations are adopted to predict viscous loss and blade outflow angle. The interactions considered are the heat transfer from main gas to coolant and the temperature and pressure losses by the mixing of two streams due to the trailing edge coolant ejection. For a stator blade without ejection, trailing edge loss calculated by the trailing edge analysis is compared with that calculated by loss correlation. The effect of heat transfer effectiveness of coolant passage on the mixing loss is analyzed. For a model turbine stage with nozzle cooling, parametric analyses are carried out to investigate the effect of main design variables(coolant mass flow ratio, temperature and ejection area) on the stage performance.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.05a
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• pp.422-429
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• 1997

피동형 격납용기 냉각계통 해석을 위하여 격납용기 압력, 온도 과도현상 분석 코드인 CONTEMPT4/MOD5 전산코드에 피동형 격납용기 열전달 모델을 추가하였다. 외부공기의 순환에 의한 철제 격납용기와 차폐건물 사이의 환형 공간의 냉각모델은 자연대류 및 혼합 대류의 기존 실험적 상관식을 사용하였고 상부에서 분사된 물의 증발에 의한 열전달 현상은 analogy 개념을 적용한 질량전달 모델을 도입하였다. 개선된 전산코드로 1000Mwe급 원전의 피동형 격납용기에 대하여 각 실험적 상관식의 차이, 물막의 형성비율, 습식냉각 지연시간 등의 민감도 분석을 수행하였다.