• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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• pp.523-526
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• 2006

A series of hydraulic and cavitation tests are performed in water environment in order to verify the hydraulic and cavitation performance of three types of LOX pumps. All the performances of the pumps are found to be satisfied with each design requirement. In the hydraulic tests, the head and efficiency are increased as the gap between floating ring seals and the impeller shoulder is decreased. In the cavitation tests, some pumps show decrease in the cavitation performance as the flowrate of the pump is decreased.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2010년 춘계학술대회논문집
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• pp.131-135
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• 2010

In the present study, the effects of the stagger angles on the aerodynamic performances in the vaned centrifugal compressor has been investigated by CFD methods. The diffuser vane angles were vane angles were varied in the range of ${\pm}10$ deg. from the intial-design points. The commercial Navier-Stokes solver, ANSYS-CFX were applied to solve the impeller-diffuser flowfields. Through the numerical results, the desirable setting angles were proposed to fit the best performance to the variation of the operating conditions.

• 한국전산유체공학회지
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• 제15권3호
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• pp.60-65
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• 2010

In the present study, the effects of the stagger angles on the aerodynamic performances in the vaned centrifugal compressor has been investigated by CFD methods. The diffuser vane angles were varied in the range of ${\pm}10$ deg. from the initial-design points. The commercial Navier-Stokes solver, ANSYS-CFX were applied to solve the impeller-diffuser flowfields. Through the numerical results, the desirable setting angles were proposed to fit the best performance to the variation of the operating conditions.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 학술대회
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• pp.171-175
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• 2008

In the present study, a numerical simulations are investigated in a stirred solid/liquid system by using Eulerian multi-phase model. The transient flow field of liquid phase and distribution of solid particles are predicted in stirred tanks consisting of 4-pitched paddles impeller and baffles. The effects of number and width of baffles on the mixing time and the quality of solid suspension in a stirred tank are presented numerically. The result shows that the mixing time decreases as the width and number of baffles increase.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2004년도 추계 학술대회논문집
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• pp.69-72
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• 2004

The performance of the centrifugal fan in a vacuum cleaner is affected by the hydraulic loss, such as the friction loss, the recirculation loss and the impact loss etc., Those losses depend on the rotational speed of the impeller, the inlet and exit widths, the relative flow angles to the blade, the number of the blades and the geometry of the shroud and the diffuser. These parameters are complicatedly interrelated, so the experimental means in analyzing the fans are rather limited. In the present study, the flow analysis are done numerically by changing the relevant fan parameters. A commercial code, STAR-CD, is used for the calculations. It is seen from the analyses that the computational results agree well with the experimental results. The results obtained can be used for the basic design of a centrifugal fan.

• 한국소음진동공학회논문집
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• 제21권8호
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• pp.726-732
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• 2011

Straight absorptive silencers have been designed to reduce the noise level of a centrifugal blower. Three-dimensional boundary element method is used for the design of absorptive silencers which consist of a perforated main pipe and a outer chamber filled with fibrous material. The experimental results show that the absorptive silencer reduces up to 8 dB(A) in the overall sound pressure level of the blower and up to 15 dB at the blade passing frequency. It is also found that the gap between the silencer and the impeller may substantially alter the acoustic performance of the silencers. The transmission loss predicted by the boundary element method follows overall trends of the measured insertion loss. The experiments also show that the impact of the silencers on the aerodynamic performance of the blower is minimum.

• 대한기계학회논문집
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• 제10권1호
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• pp.56-61
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• 1986

본 연구에서는 유체력의 조성을 명확히 함과 동시에 환상 시일부에서 발생 하는 유체력을 고려했을 때의 회전축계의 안정성에 미치는 영향을 비교 평가한다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2002년도 학술대회지
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• pp.181-184
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• 2002

CFD calculations are carried out to investigate the turbulent flow characteristics inside the duct of marine waterjet propulsors. The Reynolds-averaged Wavier-Stokes equations are solved using a finite-volume method. Standard $k-{\varepsilon}$ model and realizable $k-{\varepsilon}$ model are evaluated with an existing experimental data. Multi-block grid topology is adopted to describe the details of complex duct geometry. The present numerical methods are applied to the preliminary duct design of new waterjet propulsor system. Four different influx conditions are simulated to find out pressure and velocity distribution inside the intake duct. Attention is also paid upon the possible flow separation inside the waterjet duct. It is found that CFD tools can be used for the initial evaluation of inflow condition into the impeller of waterjet propulsor system.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.240-243
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• 2008

In this paper, the design of Centrifugal Compressor which is used in sizes 50 horse power has 8 pressure ratio and numerical analysis of the flow within compressor varying tip clearance length are performed. To get high pressure ratio with low power the exit height of impellers is low but compressor has very high speed of revolution. So compressor has high specific speed although mass flow rate is very small. The shape of impellers at the first stage is carried out. Flow and performance characteristics of impellers has been analyzed by using a commercial CFD program, $Fine^{TM}$/turbo. The result shows that loss coefficient is affected by tip clearance length and compressor has proper tip clearance length. It is possible to decrease loss by selecting apt tip clearance length.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.152-155
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• 2008

In this paper, the effect of modification of geometric variables on the performance of a centrifugal compressor blade has been studied numerically. The compressor contains six main blades and six splitter blades. Reynolds averaged Navier-Stokes (RANS) equations with shear stress turbulence (SST) model are discretized by finite volume approximations and solved on hexahedral grids for flow analysis. The design variables from blade lean angle at tip and middle of the blade have been modified. The isentropic blade efficiency and pressure have been predicted with the variation of the variables. Frozen rotor simulation is performed and adiabatic wall condition has been used. One of the six blades of compressor has been used for simulation to reduce the computational load. Optimum number of meshes has been selected by grid-dependency test, and this is used for all the simulations with changing geometric variables. The detailed flow analysis results have been reported as well as the effects of the variables.