• 항공우주시스템공학회지
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• 제13권1호
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• pp.1-10
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• 2019

교반기에서의 유동 특성은 광범위한 산업 분야에서 매우 유용하다. 일반적으로 교반되는 용기에서의 유동 패턴, 전력 소비 및 혼합 시간은 임펠러의 설계뿐만 아니라 용기 형상 및 내부 구조에 달려 있다. 본 연구에서는 베플 형상과 임펠러의 상호 작용에 의해 생성되는 불안정하고 비정상상태의 복잡한 유동 특성 분석을 ANSYS FLUENT LES 난류 모델을 사용하여 수행하였다. Axial Flow 와 Radial Flow 두 가지 타입의 회전 임펠러와 3가지 베플의 형상 사이의 상호 작용과 영향을 전산유체역학(CFD)으로 예측 비교함으로써 교반 시 임펠러와 베플 주변에서의 유동 특성과 혼합 유동장에서 상대적으로 효율적인 경향을 보이는 설계 모델을 검증할 수 있었다.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1998년도 추계학술발표회요약집
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• pp.369-369
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• 1998

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1999년도 춘계학술발표회요약집
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• pp.438-438
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• 1999

• Journal of Advanced Marine Engineering and Technology
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• 제18권3호
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• pp.43-51
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• 1994

The design technique of turbo pumps has been developed due to an increasing demand from related industrial fields. But infant stage of turbomachinery in the domestic industry needs more fundamental design method. Among various types of pumps, centrifugal pump was chosen because of its wide industrial application. It is difficult to decide the correct specification of centrifugal impeller, because of its complex flow analysis at the inlet, passage and outlet. This study is limited on the impeller blade design and its related performance analysis.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2003년도 유체기계 연구개발 발표회 논문집
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• pp.353-360
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• 2003

Hydraulic performance and cavitation characteristics of fuel pump in turbo-pump were studied experimentally. The fuel pump has a centrifugal impeller with a separate inducer. In this paper, flow characteristics of inducer and impeller was experimentally investigated separately and together. Especially static pressure distribution of Inducer was examined in non-cavitation and cavitation conditions.

• 대한기계학회논문집B
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• 제23권8호
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• pp.957-968
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• 1999

Performance tests of an airfoil fan and measurement of flow fields at the impeller exit are carried out to investigate the effects of the tip clearance between the rotor and inlet casing on the impeller performance. The impeller is twelve bladed of NACA 65-810 airfoils and tested with 3 different size of gap; 1, 2, 4mm. The relative decrease of pressure rising performance of the fan is 15 percent for the design flow rate when the gap size is 1 percent of the impeller diameter. The reduction of performance becomes large as the flow rate increases. The leakage flow through the clearance affects the through flow of the impeller, which results in decrease of the slip factor as well as the impeller efficiency. The data base obtained in the present study can be used for the design and flow analysis of the airfoil fans.

• 한국가시화정보학회지
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• 제8권4호
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• pp.19-25
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• 2010

The flow field measurements were conducted on the planes between impeller blades, and the gap between the impeller and turbine blades under speed ratio of 0.4. The study showed that high velocity regions move from locations near the suction surface of the impeller to the pressure blade, shroud corner as flow progresses from the mid-chord of impeller passage to exit and out into the gap region. Planes 3 through 5 also showed flow reversal occurring in the area near the shell surface and progress far into the impeller passage from the impeller passage exit, near shell surface. This affected the converter efficiency negatively. This study would aid in the construction of higher accuracy CFD models of this complex turbomachinery device.

• 한국초지조사료학회지
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• 제36권4호
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• pp.298-302
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• 2016

본 연구는 2013년 5월 22일~24일 3일에 걸쳐 톨 페스큐엔도파이트 프리 품종인 Jesup을 공시하여 톨 페스큐 위주의 목초지에서 수행되었다. 시험기간 평균 온도는 $20.7^{\circ}C$였고 상대습도는 3일평균 64.8%였다. 일조시간은 3일평균 9.27시간으로 건초를 조제하기에 알맞은 기상조건이었다. 컨디셔너별 처리 (임펠러, 로울러)와 무처리로 3가지 처리를 비교하였고, 반전횟수에 따른 차이를 확인하기 위해 임펠러 컨디셔너로 예취한 후 1일 1회 반전, 1일 2회 반전 두 처리를 두었다. 임펠러와 로울러의 수분함량 변화는 둘째날 5월 23일 13시 임펠러 37.30%, 로울러 33.64%였고 무처리구는 51.75%로 컨디셔닝 처리한 두 구와 차이가 컸다. 24일 13시 측정된 수분함량은 임펠러 20.32%, 로울러 19.37%로 20% 전후를 보였고, 무처리구는 28.84%로 약 8~9%의 차이를 보였다. 반전횟수 차이를 보는 실험에서는 23일 13시 1회반전 37.53%, 2회 반전 35.23%였고 24일 13시 1회 반전시 20.48%, 2회 반전시 16.74%로 나타났다. 건초 사료가치 분석 시 컨디셔너별 CP 함량은 무처리 12.5% 임펠러 12.7% 로울러 12.9% 나타났고, ADF는 무처리 37.2%, 임펠러 37.2%, 로울러 35.1%로 나타나 NDF, TDN, RFV 모두 차이는 없었다. 1회 반전시 CP 함량은 12.7%, 2회 반전 12.8%였고 반전횟수에 따른 사료가치의 차이는 없는 것으로 판단된다.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2001년도 춘계 학술대회논문집
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• pp.203-208
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• 2001

Any circumferential variations of the impeller exit flow conditions influences on the volute inlet flow conditions. All these interactions are strongly coupled phd affect consequently the performance of centrifugal pumps. In this paper, a commercial CFD code, which solves three-dimensional quasi-steady Wavier-Stokes equations with an impeller/volute interaction, is used for the prediction of a centrifugal pump performance. The simplified model of an impeller/volute interaction requires affordable computing time and provides relevant results. As a result, detailed flow structures such as pressure rise, recovery and loss mechanism on the centrifugal pumps are obtained. Especially, hydraulic performances are compared between the case of impeller only and the case of impeller with volute configuration. In addition, pump performance at off-design operation are observed and discussed.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2007년도 추계 학술대회논문집
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• pp.92-99
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• 2007

In this paper, optimization of the vaned centrifugal compressor was carried out at a given mass flow rate condition. Firstly, impeller optimization was conducted using response surface method (RSM) which is one of optimization methods. After the optimization of the impeller was completed, diffuser optimization was performed with the optimized impeller. In these processes, Navier-Stokes solver was used to calculate the flow inside the centrifugal compressor. And the optimization is performed with Box-Behnken design method which is efficient for fitting second-order response surfaces to reduce the number of calculations required. As a result, compared with the reference model, the efficiency and the pressure ratio of the optimized impeller and diffuser are found to be increased. The performance at off-design conditions is presented.