• 대한기계학회논문집
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• 제17권12호
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• pp.3148-3165
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• 1993

A cascade wind tunnel test for a turbine nozzle, which was designed for a small turbo jet engine in a previous study, has been conducted to evaluate its aerodynamic performance and losses. The large-scale blades were based on the mid-span profile of the nozzle. Oil film flow structure, and then 3-dimensional velocity components were measured in the flow passage with a 5-hold pressure probe, in addition to turbulent intensities at mid-span of cascade exit using a hot-wire anemometer. From this study, 3-dimensional growth of horseshoe and passage vortices in the downstream direction was clearly understood with near-wall flow phenomena. In addition, secondary flow and losses associated with the blade configuration were obtained in detail.

• 대한기계학회논문집
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• 제19권3호
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• pp.784-795
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• 1995

This paper represents the results of the experiments of the three-dimensional flow and the aerodynamic loss caused by the three-dimensional flow within the plane bucket blades. To research the secondary flow and the aerodynamic loss, the large-scale plane bucket blade of lst-stage in the low pressure steam turbine is made of FRP. The detailed investigation of the secondary flow and the aerodynamic loss using 5-hole pressure probe within turbine cascade has been carried out in the low speed wind tunnel. The limiting streamlines of the suction and endwall surface have been visualized by the oil film method. The flow visualization of the secondary flow has been performed by the laser light sheet technique and image processing system. By using the method mentioned above, it is possible to observe the evolution of the pitchwise mass-averaged flow deviation angle and total pressure loss coefficient, the secondary flow, and the aerodynamic loss through the cascade.

• 대한기계학회논문집
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• 제19권9호
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• pp.2386-2398
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• 1995

The paper describes the results of an experimental investigation of the heat transfer rate on the endwall surface within the plane turbine cascade passage and includes the effect of the heat transfer for the two different boundary layer thicknesses and Reynolds numbers. The limiting streamlines on the endwall surface have been visualized by the oil film method in order to compare with the endwall heat transfer. The hue-capturing method using the termochromatic liquid crystals with great spatial resolution has been used to provide the local distribution of the endwall heat transfer coefficients. Because the detailed contours of the local heat transfer coefficients over the entire endwall can be obtained from the hue-capturing method, it has been possible to obtain information on the endwall heat transfer within the plane turbine cascade passage from these heat transfer contours.

• 한국항공우주학회지
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• 제32권9호
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• pp.94-102
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• 2004

본 연구에서는 회전하는 터빈에서 입사각을 변경하면서 성능을 측정하여, 최적의 입사각을 찾기 위한 실험적 연구를 수행하였다. 입사각은 터빈 익형의 설계에 중요한 설계변수이기 때문에 최적의 입사각을 찾기 위한 실험적 연구가 많이 수행되었었다. 하지만 대부분의 연구가 직선형이나 환형의 케스케이드에서 수행되었기에 이러한 실험장치에서 얻어진 최적의 입사각을 회전하는 터빈에 적용하는 것은 문제가 없다. 따라서 본 연구에서는 회전하는 터빈에서 입사각의 변경에 다른 성능을 측정하여 최적의 입사각을 얻고자 하였다. 실험결과는 터빈의 성능이 입사각의 변경에 따라 상당한 영향을 받고 있음을 보여주고 있으며 적용 가능한 입사각의 범위는 터빈에 가하여지는 입력공기력의 증가에 따라서 좁아지는 경향을 보여주고 있다. 본 실험에 적용된 익형에서의 최적입사각은 $-12^{\circ}$를 나타내었다.