• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년 영문 학술대회
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• pp.403-406
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• 2008

The performance of an entire pump system composed of an inducer, an impeller, a volute and seals has been computationally analyzed. A commercial three dimensional Reynolds Averaged Navier-Stokes method is used in this study. The axial thrust is predicted from the pump calculation in its entirety, which is necessary for such estimation. Moreover, the effects of each component on the pump performance are investigated at a design condition through the analysis of flow structures. The predicted performance is in good agreement with experimental data in terms of head rise, efficiency and volute wall pressure distributions despite of highly complex flow structures being present. The computational results also show that the axial and radial thrusts are within the design limit although corresponding experimental measurements were not taken.

• 드라이브 ㆍ 컨트롤
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• 제14권2호
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• pp.37-44
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• 2017

In this study, in order to prevent cavitation in a variable swash-plate type hydraulic pump, a basic model impeller has been applied to a new pump, and the impeller shape has been optimized through flow analysis. Based on the analysis results, we could propose an impeller shape with high efficiency and low possibility of cavitation in comparison with the basic model. The simplification of the basic shape of the impeller of the hydraulic pump was performed in three parts in the order of hub shape, wing, and curvature, and eight design parameters were defined to satisfy the design requirement. Compared with the initial model of the impeller, when the differential pressure of the optimum model increased, the efficiency was improved. It achieved the goal of design improvement because cavitation did not occur under the rated operating conditions.

• 한국유체기계학회 논문집
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• 제6권4호
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• pp.50-57
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• 2003

The hydraulic performance analysis of a turbopump with an inducer for a liquid rocket engine was performed using three-dimensional Navier-Stokes equations. A simple mixing-plane method and a full interaction method were used to simulate inducer/impeller interaction. Two methods show almost similar results due to the weak interaction between the inducer and impeller since the inducer outlet blade angle is lather small. But, when the inducer and the impeller are closely spaced near the shroud region, flow angles at the impeller inlet show different results between two methods. Thus, the full interaction method predicts about $2\%$ higher pump performance than the mixing-plane method. And the effects of prewhirl at the impeller inlet are also investigated. As the inlet flow angle is increased, the head rise and the efficiency are decreased. The computational results are compared with measured ones. The computational results at the design point show good agreements with experimental data, however under-predicts the head rise at high mass flow rates compared to the experiment.

• 한국유체기계학회 논문집
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• 제10권6호
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• pp.38-43
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• 2007

Pumps for a turbopump generally operate under high rotational speeds and large head rise conditions. Therefore, reliability is a prime design requirement. Floating-ring type seals are frequently employed in a turbopump because of robustness despite of low hydraulic efficiency. There are many researches on the floating-ring seal itself, but the effects of the floating ring seals on the performance of the whole pump are not widely studied in spite of their importance. In the present study, experimental and computational studies on the effects of the radial clearance of the floating ring seals on the performance of a pump were performed. The experimental results showed that the head rise and efficiency increased as the floating-ring seal clearance was decreased. The results also showed the possibility that the leakage flow which was injected to the inlet of the inducer could enhance the suction performance of the inducer by diminishing the size of the backflows.

• 한국전산유체공학회지
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• 제11권1호
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• pp.16-20
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• 2006

The present study focuses on the flow analysis of a turbo pump inducer by performing both numerical and experimental methods. The head rise, efficiency and detailed flow fields such as outlet flow angles, pressure and velocity vectors are measured and compared with the computational data. Generally a good agreement is obtained between numerical and experimental results. However, some discrepancies are observed due to complex flow structures inside the inducer. Future calculations with an advanced turbulence model and a dense computational grid needs to be performed to obtain accurate numerical solution for the detailed flow fields.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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• pp.234-239
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• 2004

In the development of rocket turbo-pump, cavitation at the inducer is one of the major problems. Cryogenic fluids are commonly used for rocket propellant, therefore, thermodynamic effect becomes noticeable compared to conventional water cavitation. In the present study, a numerical simulation method for cryogenic cavitation is proposed, which reveals the difference between cryogenic and water cavitation.

• International Journal of Fluid Machinery and Systems
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• 제9권3호
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• pp.213-221
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• 2016

Due to the nature of cavitation numerical analyses, computational optimization of a pump with respect to the cavitation properties is extremely demanding. In this paper it is shown how a combination of Transient Blade Row (TBR) method and some simplifications can be used for making the optimization process more efficient and thus possible on current generation of hardware. The aim of the paper is not the theory of hydraulic design. Instead, the practical aspects of numerical optimization are shown. This is done on an example of a radial pump and a combination of ANSYS CFX, ANSYS software tools and custom scripts is used. First, a comparison of TBR and fully-transient simulation is made. Based on the results, the TBR method is chosen and a parametric model assembled. Design of Experiment (DOE) table is computed and the results are used for sensitivity analysis. As the last step, the final design is created and computed as fully-transient. In conclusion, the results are discussed.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.144-147
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• 2008

Intake pump for waterworks is badly damaged by a small amount of cavitation because of variable water quality and severe operation conditions. In general, the required NPSH for reduced cavitation can be provided by inlet condition, supply air, change pump and inducer. But once the pump has been built and installed there is little that can be done to reduce cavitation damage. In this study, we analysed the cavitation of paldang intake pump and intended to avoid the same phenomena.

• 항공우주기술
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• 제6권2호
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• pp.205-210
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• 2007

75톤급 액체 로켓 엔진용 터보펌프의 산화제펌프에 대한 로터다이나믹 설계를 수행하였다. 인듀서와 임펠러 및 베어링의 축배치는 항우연에서 개발 중인 유사한 구조를 가지는 터보펌프를 근간으로 하였고, 75톤급 산화제펌프 수력 설계에 맞추어 인류서, 임펠러의 축길이가 반영되었다. 후방 베어링으로부터 임펠러까지의 거리를 베어링 하중 설계에 대한 설계 변수로 고려하였고, 전방 베어링과 후방 베어링의 강성을 변화시키면서 회전 속도에 따른 비동기 고유진동수 해석을 수행하여 산화제 펌프의 임계속도를 고찰하였다. 베어링에 적절한 하중이 부과된다면 산화제 펌프의 임계속도는 기준속도 11,000 rpm과 비교하여 충분히 높기에, sub-critical 로터로서 기준속도 이내에서 안정적인 터보펌프의 운용이 가능하리라 판단된다.

• 한국추진공학회지
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• 제22권4호
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• pp.61-67
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• 2018

액체로켓엔진용 산화제펌프의 캐비테이션 시험 중 입출구 배관과 펌프 케이싱에서 계측된 고주파 신호를 분석하였다. 각각의 데이터의 RMS 값을 캐비테이션 수에 따라 표현하였다. 또한 회전수 동기 주파수와 날개 개수 성분, 캐비테이션 불안정성 주파수의 크기를 검토하였다. 입출구 배관의 압력섭동은 캐비테이션 불안정성의 영향을 받았다. 출구 배관의 신호에서는 인듀서 날개 주파수인 3x 성분이 탁월하였다. 이러한 현상은 임펠러의 날개 개수가 인듀서의 날개 개수의 배수인 것과 관계가 있는 것으로 추정된다. 케이싱에 부착된 가속도계에서도 캐비테이션 불안정성 주파수가 확인되었다.