• Transactions of Materials Processing
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• v.18 no.2
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• pp.160-165
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• 2009

A Study on Effects of the Runner and the Gate of double shot injection molded Parts using CAE Double shot injection molding can inject two different materials or two different colors in the same mold in a injection molding process. Double shot injection molded parts can be characterized that the base part maintains strength and specified part can inject soft-material. It can reduce the production cost by single automatic operations. In this paper, we designed double shot injection mold for automobile emote control To inject secondary part, this part is used as an insert after external appearance of product is injected. CAE analysis was progressed gate location and runner size as variables. The analysis result is reflected in mold design process. As a result, it could solve problems which are generated in the conventional mold. Additionally, cost can be downed by reducing runner weight. As well as it could omit painting process because the surface of finished product is improved through new mold.

• Transactions of the Korean hydrogen and new energy society
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• v.31 no.3
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• pp.314-321
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• 2020

In this work, a preliminary design of an inlet guide vane and runner for developing a 2.5 kW hydraulic turbine was conducted by using computational fluid dynamic analysis. Three-dimensional Reynolds-averaged Navier-Stokes equations with shear stress transport turbulence model were used to analyze the fluid flow in the hydraulic turbine. The hexahedral grid system was used to construct computational domain, and the grid dependency test was performed to obtain the optimal grid system. Velocity triangle diagram considering the flow angles of the inlet guide vane and runner was analyzed to obtain a basic geometry of the inlet guide vane and runner. Through modification of the preliminary design, the hydraulic performances of the turbine have improved under overall drop conditions. Especially, the efficiency and power of the turbine increased by 0.95% and 1.45%, respectively, compared to those of the reference model.

• Design & Manufacturing
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• v.2 no.6
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• pp.23-27
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• 2008

It is well known that the family-mold has an advantage to reduce the cost for production and mold. However, defects are frequently occurred by over packing the smaller volume cavity during molding, especially when the family-mold has a volumetric difference between two cavities. In this study, the cavity-filling imbalance was confirmed by the temperature and the pressure sensors, and a variable-runner system was developed for balancing the cavity-filling. Experiments of balancing the cavity filling was carried out in the family-mold with the variable-runner system, and balancing the cavity-filling was confirmed by changing the cross-sectional area of a runner in the variable-runner system with the temperature and pressure sensors. The influence of the injection speed to the balancing-capability of the variable-runner system was also examined in the experiment.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.6
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• pp.1020-1027
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• 2003

A traditional mold design has been conducted by an experience-based trial and error, whereby the mold designer would decide the gate locations and processing conditions based on the caring characteristics and its functional requirements. The paper suggests an optimal gate location and processing conditions in the injection molding using a global search method referred to as micro genetic algorithm( ${\mu}$ GA). ${\mu}$ GA yields the optimal solution with a small size of population without respect to design variables for saving time that is needed to calculate the fitness of many individuals. Due to the reason, the paper uses a commercial analysis package of injection molding(CAPA) to analysis a state of flux. In addition to that, axiomatic approach .is applied in the beginning of design. It is a useful method to draw a well-organized and reasonable idea to handle a problem.

• The KSFM Journal of Fluid Machinery
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• v.17 no.2
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• pp.5-11
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• 2014

Small hydro power, among other renewable energy resources, has been evaluated to have enough development value because it is a clean, renewable and abundant energy resource. In addition, small hydro power has the advantage of low cost development by using existing facilities like sewage treatment plants, water works and similar resources. But in the case of small hydro power systems, there are problems with degraded operation efficiency of turbine due to changes in flow rates. In order to overcome this, variable speed control can be achieved by using the power rectifier and permanent magnetic synchronous generator(PMSG) as a possible method to respond to the changes in flow rates. In this study, a commercial ANSYS CFD code was used to analyze the performance of 10kW class propeller hydro turbine and to also investigate flow characteristics at variable flow rates and runner vane.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2009.05a
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• pp.223-226
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• 2009

최근 의생활에 있어서 가장 큰 변화는 쾌적성의 추구와 건강을 중심으로 한 기능성 소재에 대한 소비자들의 욕구가 증대된다는 것이다. 천연 섬유 중 모시는 통기성이 우수하고 감촉이 깔깔하여 고온 다습한 우리나라의 여름철 옷감으로 좋으므로 현대 의생활로의 도입이 요구되고 있다. 그동안 모시직물은 심미적인 욕구에도 잘 맞아 한국인의 정서에 좋은 이미지로 자리 잡고 있지만 수공예적 생산방식을 그대로 답습하고 있어 전통모시직물로는 많이 이용이 되어왔으나 현대 방적모시직물을 이용한 새로운 직물디자인 개발은 이루어지기 어려운 실정이었다. 그러나 최근 방적모시섬유에 대한 연구가 활발하게 진행되기 시작하면서 현대 방적모시직물의 생산이 가능하게 되었다. 따라서 본 연구에서는 원사의 특성과 제조공정 특성에 의해 미세한 감성촉감의 차이를 유발하기 좋은 폴리에스터를 경사로하고 방적모시와 라이오셀을 위사로 하여 현대 모시직물의 개발을 시도하였다. 모시의 소비를 증가시키고 현대인의 감성에 맞게 심미성을 향상시킬 수 있도록 직물문양을 디자인하였다. 직물의 복잡한 문양을 컴퓨터로 디자인하고 자동으로 제직이 가능하게 하는 시스템인 EAT 프로그램을 이용하여 자카드 직물 특유의 고급스러움을 살리며 공정과정에서의 실의 밀림 등을 고려하며 조직을 설계하였다. 설계된 직물은 제직 후 염색 가공하여 쿠션, 방석, 테이블 러너 등의 시제품으로 제작하여 고부가가치 모시제품의 개발가능성을 살펴보았다.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.4
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• pp.418-423
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• 2014

Small hydropower has been considered as a solution to resolve the problem of exhaustion of fossil fuel and industrial pollution. In this study, we developed and tested a Cross-Flow Turbine with two guide vanes to optimize the small hydropower for the site condition with large fluctuation of head and flow rate. Furthermore, in the condition of constant inlet head, CFD analysis was carried out to analyze the effect of air suction and valve position on the performance characteristics. The results showed that the air suction can minimize the hydraulic loss caused by the Recirculation flow in the runner passage and flow impact on main shaft so that it can increase the turbine efficiency and output power.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.6
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• pp.117-121
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• 2004

Injection molding is the one of the most important processes for mass production of plastic parts. Usually injection molds for mass production are constituted to multi-cavity runner system to manufacture the more parts at a time. Multi-cavity molds are designed to geometrically balanced runner system to uniformly fill to each cavity. But, when injection molding is performed using a mold with balanced runner system filling imbalances are occurred between the cavity to cavity. The previous studies by Beaumont at. all reported that filling imbalance occurred by thermal unbalance on the mold and viscosity variation of resins and so on. In this study, we conducted experiments in order to know the causes of filling imbalance for 3 plate type mold with 8 cavities. And we exhibited a new so called 4BF mold (4 plate type Balanced Filling Mold) to be possible filling balance. We conducted a experimental injection molding to verify the efficiency of the 4BF mold. In the results of the experiment, we could confirmed the balanced filling possibility of the 4BF mold.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.977-979
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• 2015

최근, 에디터 형태의 게임엔진들이 제공되어 게임 제작의 높은 진입장벽이 낮아지고 있다. 본 논문은 에디터 형태의 게임엔진 중 하나인 Unity 3D를 활용하여 일반 사용자의 관점에서 혼자 게임을 제작하기 위한 방법으로 이벤트기반 모듈 기획 방법을 제안하고자 한다. 이는 1인 게임 제작의 관점을 기획에 맞추어 게임의 전체적인 진행과정에서 동작하는 행동과 역할들을 모듈 단위로 기획하는 방법이다. 그리고 각 모듈은 게임성을 표현하는 다양한 이벤트들을 포함한다. 또한 Unity 3D에서 제공하는 스크립트 기능은 제안하는 모듈 구조를 구현하기에 적합하여 Unity 3D를 활용한다. 마지막으로 제안하는 방법을 통해 기획에서 개발까지 효과적인 게임 제작이 가능한지 여부를 확인하기 위해 간단한 모바일 캐주얼 게임을 제작하였다.

• Transactions of the Korean hydrogen and new energy society
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• v.31 no.4
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• pp.387-394
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• 2020

A parametric study of a 2.5 kW class propeller type micro hydraulic turbine was performed. In order to analyze the internal flow characteristics in the hydraulic turbine, three dimensional Reynolds-averaged Navier-Stokes equations with shear stress transport turbulence model were used and the hexahedral grid system was used to construct computational domain. To secure the reliability of the numerical analysis, the grid dependency test was performed using the grid convergence index method based on the Richardson extrapolation, and the grid dependency was removed when about 1.7 million nodes were used. For the parametric study, the axial distance at shroud span (L) between the inlet guide vane and the runner, and the inlet and outlet blade angles (β₁, β₂) of the runner were selected as the geometric parameters. The inlet and outlet angles of the runner were defined in the 3 spans from the hub to tip, and a total of 7 geometric parameters were investigated. It was confirmed that the outlet angles of the runner had the most sensitive effect on the power and efficiency of the micro hydraulic turbine.