• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2006년도 PARALLEL CFD 2006
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• pp.247-247
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• 2006

• Journal of Biosystems Engineering
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• 제32권2호
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• pp.77-83
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• 2007

The purpose of this study is to find optimal conditions for various outlet clearances of prototype garlic clove separator with a rotating cone in the constant inlet clearance and cone height. Optimal outlet clearance from medium to small size garlics was 25 mm at the $200{\sim}400rpm$. For large garlic, optimal outlet clearances of Namdo and Uiseong garlic were 34 mm and 37 mm, respectively, in the range of $300{\sim}400rpm$. The proportion of garlic separation was over 95% for all quality of garlics. The proportions of damaged garlics at 25 mm and 28 mm outlet clearances were below 5% and below 10%, respectively. Therefore, in order to maintain high performance of garlic separation for the various varieties and qualities, the rotating cone type separator should be designed with cone speed ranges of $200{\sim}400rpm$ and the outlet clearance ranges of $25{\sim}37 mm$. The outlet clearance of the separator should be easily controlled within those ranges.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2004년도 춘계 학술대회논문집
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• pp.35-41
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• 2004

A numerical investigation has been made for flows in an axisymmetric circular cylinder with a rotating cone located at the bottom of the container. The axisymmetric container is completely filled with a viscous fluid. Major parameter for the present research is the vertex angle of the cone, otherwise Reynolds number of fluid and aspect ratio of the vessel is fixed. Main interest is in vortex breakdown of meridional circulation by rotation of the cone with respect to the longitudinal axis of the cylinder. The method to this problem is numerically to integrate momentum and continuity equations on a generalized body fitted grid system. The pattern of vortex breakdown is quite different from that in a right circular cylinder with flat end wall disks. Flow visualization photographs of a preceeding work are compared with the present numerical results.

• 대한기계학회논문집
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• 제7권3호
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• pp.278-285
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• 1983

The momentum transfer in axisymmetric turbulent boundary layer over a rotating cone submerged in a free stream was studied by experiments and numerical analysis. In numerical analysis the velocity profiles were calculated by finite difference method using Prandtl mixing length concept, and the results were compared with experimental results. The agreement was good. By the numerical analysis the wall fircition coefficient was increased as the Reynolds number increased when the rotational speed is large, but the wall friction coefficient was decreased as the rotational speed increased.

• 설비공학논문집
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• 제9권1호
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• pp.55-63
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• 1997

A numerical investigation has been made for flows in an axisymmetric circular cylinder with an impulsively rotating cone located at the bottom of the container. The axisymmetric container is completely filled with a viscous fluid. Major parameter for the present research is only the vertex angle of the cone, otherwise Reynolds number and aspect ratio of the vessel are fixed. Main interest concerns on the vortex breakdown of meridional circulation by impulsive rotation of the cone with respect to the longitudinal axis of the cylinder. Numerical method has been used to integrate momentum and continuity equations on a generalized body-fitted grid system. The pattern of vortex breakdown is quite different from that in a right circular cylinder with flat endwall disks. The flow visualization photograph of the preceeding work by Escudier is compared with the present numerical results and the two results are in good agreements. Also flow data are plotted to gain a deep understanding for the present phenomena of the vortex breakdown. The conclusions of this work are clearly explained by the classical theory of the vortex flows in a finite geometry.

• 드라이브 ㆍ 컨트롤
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• 제11권4호
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• pp.46-52
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• 2014

This study suggests a small-sized screw decanter specialized for dredging sites. Generally, conventional screw decanters are composed of a cylinder and a cone. However, the suggested screw decanter simply has a cone based on a cone-type bowl structure. In this research, a commercial analysis tool is used to establish an optimal design for the bowl and the screw conveyor. Moreover, the base frame, where the main bearings that support the spindle of the bowl and the screw conveyor are installed, is optimally designed considering the weight of the rotating body and the deflection caused by the high centrifugal force. Furthermore, the natural frequency range of the spinning body, the bowl and the screw conveyor, is applied to this base frame; it is designed not to correspond to the resonance frequency range and achieves stability as a result. This study suggests an optimal design for the rotating body and the base frame of a screw decanter considering its vibration characteristics. Such a design will prevent overuse of materials and help to reduce the weight and volume-and the price-of a screw decanter.

• 드라이브 ㆍ 컨트롤
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• 제19권4호
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• pp.77-84
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• 2022

The aims of this study was to estimate transfer force delivered to cone crusher housing and contribution of force transmission. The rock crushing condition caused vibrations in the cone crusher housing, which were experimentally measured, and frequency response functions (FRF) were also found through modal impact tests. Vibration data and frequency response functions were applied to the transfer path analysis (TPA) model. Next, transfer forces delivered to the cone crusher housing were quantified via the TPA method. Contribution of force transfer was also analyzed based on force estimation results. Finally, this study describes basic concepts and components of the TPA method and reviews its applicability to rotating machinery that experiences impact vibrations and forces.

• Journal of Biosystems Engineering
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• 제32권2호
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• pp.84-90
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• 2007

This study was conducted to design and manufacture a final prototype of garlic separator and to evaluate its performance. The performance of garlic separation was compared with manual separation. The final prototype for garlic separation consists of bucked-elevator device for automatic feed of garlic, rotating cone typed device, blower, and power transmission device. The optimal condition of outlet clearance was 19 mm and in this clearance, the proportions of fragment garlic separated in the large quality of Namdo garlic and all quality of Uiseong garlic were above 95% and above 85%, respectively. All proportion of damaged garlic was below 5% for all variety and quality. The garlic separation capacities of this developed machine were 310 kg/h for Namdo garlic and 293.6 kg/h for Uiseong garlic in the large quality. Capacities of final prototype compared with human being were $12.9{\sim}19.6$ times for Namdo and $24.2{\sim}31.7$ times Uiseong garlic, respectively.

• Journal of Biosystems Engineering
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• 제6권1호
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• pp.48-59
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• 1981

The major limiting factor on the determination of combine capacity is the frequent occurence of clogging over the some parts of machine when the crop is wet in the case of Japanese self-feeding type combine. And in the case of American conventional combine having big separating parts, the great grain loss and damage occur when the machine is used for rice harvesting. This experiment was carried out to develop the new type threshing and separating equipment. Proto-type thresher which consist of a conical threshing drum and a conical separating sieve rotating around the threshing cone was constructed and tested. In the case of 800 rpm of threshing cone speed, average threshing loss was below 1 percent, separating loss was about 1 percent, grain damage was about 0.4 percent, and average total power required was about 2.6 PS. This design has some problems such as higher power required or wrapping problems under the conditions of feeding long damp straw. But, compared with the conventional combine or thresher, this machine certainly has some potentials for this approach to combine development. The crop feed rate must be increased through improvement of the feeding portion of the threshing cone. And it is required to investigate further about some parameters causing wrapping phenomena.

• 한국분무공학회지
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• 제6권4호
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• pp.39-48
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• 2001

The Gasoline Direct Injection(GDI) system has been highlighted due to the improvement of fuel consumption and the control of exhaust emission from gasoline engines. Main purpose of the present study is to measure spray characteristics of GDSI for real engine application. We have investigated experimentally spray tip penetration, spray angle, tip velocity and spatial spray distribution. Counter-rotating vortex grown on the spray surface plays an important role in the spray characteristics. Accordingly the spray tip penetration and tip velocity do not excess 50mm, 20m/s respectively, under 0.6MPa ambient pressure. the spray cone angle of GDSI have a same tendency to a simplex swirl atomizer.