• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.370-373
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• 2009

The runner-valve is an effective solution for the filling balance of the multi cavity molds. Automation of the runner-valve system is necessary for more efficient and accurate control of the filing balance. We designed an automatic runner-valve actuator for the automation and characterized the actuator by experiment. We obtained a linear relationship between motor-driving time and the height of the runner-valve. However, the motor-driving times for upward and downward directions were different due to the frictional characteristics of the actuators. Also we obtained the motor-driving times for backlashes of the 4 actuators. The results were used to formulate the relationship between the resin-arrival time and the flow rate change of the runner-valve with the theoretical equation that was derived in the previous research.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.115-115
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• 2004

최근에는 자동차용 범퍼(Bumper), 인판넬(In-panel), 도어판넬(Door panel), 도어가니쉬(Door Garnish) 등과 같은 대형 사출성형품을 성형하기 위한 금형설계에 핫 러너 시스템(Hot Runner System)에 밸브 게이트(Valve Gate)를 채용한 밸브 게이트 시스템을 많이 사용하고 있다 이 시스템을 사용함으로서 성형 싸이클타임의 단축, 수지 스크랩의 감소 등의 말은 장점이 있으나, 실제 성형작업 적용 시 밸브 게이트의 작동순서 및 개폐시간의 제어 등에 정확한 표준이 없어 시험 사출시 최적 성형조건의 셋팅이 많은 시간을 소모하고 있는 문제점이 있다.(중략)

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.05a
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• pp.381-388
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• 2003

The paper presents our study of development for multi-cavity preform mold system which consists of hot runner system and valve gate. For this purpose, stretching blow molding process and preform injection process were simulated by Polyflow and Moldflow. Based on various results of the preform injection process analysis, process planning was established. The sectional thickness distribution of preform was optimized. Preform injection mold system was designed by these technical analysis data. Finally, 24-cavity preform mold system was successfully developed.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.2
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• pp.115-122
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• 2014

Injection pressure is one of factors that influence part quality. In this paper, injection pressure was minimized by optimizing valve gate locations. In order to perform design optimization, MAPS-3DTM (Mold Analysis and Plastic Solution-3D) was used for injection mold analysis and PIAnOTM (Process Integration, Automation and Optimization) was used as process integration and design optimization. Also we adapted meta models based on design of experiments for efficiency. By using introduced methodology, we were able to obtain a result so that maximum injection pressure reduced by 28% compared to the initial design. And the validity of the proposed method could also be demonstrated.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.5
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• pp.397-402
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• 2016

This study presents the performance characteristics of a small Francis turbine with an inline casing and is a continuation of a previous study. A new runner design has been implemented using the previous facility. The specific speed of the new runner has been modified from $N_s$ 80 to $N_s$ $100m-kW-min^{-1}$. This turbine can be installed in a city water supply system. To dissipate excess pressures in the water line system an inline-turbine can be used instead of an inline-pressure reducing valve. Thus, some of the energy can be recovered by utilizing the pressure difference. For best applicability and minimal space consumption, the turbine is designed with an inline casing instead of a common spiral casing. As a characteristic of inline casing, the flow accesses to the runner are in the radial direction, showing low efficiency. The installation of vanes improves the internal flow and positively affects the output power. In contrast to the previous study, the new runner reduces the effect of the stay vanes by maintaining a higher efficiency.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2839-2844
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• 2007

Micro hydraulic power generation of which the output is less or equal to a 100kW is attracting considerable attention. This is because of its small, simple, renewable, and abundant energy resources. By using a small hydropower generator of which main concept is based on using the different water pressure levels in pipe lines, energy which was initially wasted by use of a reducing valve at the end of the pipeline, is collected by turbine in the hydropower generator. A propeller shaped hydroturbine has been used in order to use this renewable pressure energy. In this study, in order to acquire basic design data of tubular type hydraulic turbine, output power, head, efficiency characteristics due to the flow coefficient are examined in detail. Moreover influences of pressure and velocity distributions with the variations of runner vane angle on turbine performance are investigated by using a commercial CFD code.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.5
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• pp.62-67
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• 2010

Exhausting fossil fuel and increasing concern of air pollution have brought on the change of the focus of developing new vehicles from performance to fuel economy and emission. The gasoline engines adopting the naturally aspirated way use the throttle-body for engine load control. Therefore, its pumping loss increases more than that of the diesel engine, and also mostly operating in a partial load condition has bad influence on fuel economy and emission. In these days, the continuous variable valve timing system and variable induction system are adopted in order to improve fuel consumption and emission. In this study, we optimize the runner length and operate region of variable induction system to simulataneously improve the performance, fuel economy, and emission of gasoline engine with employing GT-Power as a CAE tool for engine analysis and PIAnO as PIDO tool for process integration and design optimization.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.7
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• pp.1044-1050
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• 2008

Most of developed countries, the consumption of fossil fuels has been serious problems that cause serious environment pollution like acid rain, global warming. Also, we have faced that limitation fossil fuels will be exhausted. Currently, small hydropower attracts attention because of its small, clean, renewable, and abundant energy resources to develop. By using a small hydropower generator of which main concept is based on using the different water pressure levels in pipe lines, energy which was initially wasted by use of a reducing valve at the end of the pipeline, is collected by turbine in the hydropower generator. A propeller shaped hydroturbine has been used in order to use this renewable pressure energy. In this study, in order to acquire basic design data of tubular type hydraulic turbine, output power, head, efficiency characteristics due to the flow coefficient are examined in detail. Tubular-turbine among small hydraulic power generation can be used at low-head. The purpose of this study is to research turbine's efficiency due to runner vane angle using CFD analysis.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.6
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• pp.908-914
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• 2008

The world is facing a serious energy problem which destroying the environment. In addition, fossil fuel such as oil and coal that caused global warming and the environmental problems due to acid rain had been gradually exhausted. To solve this problem that has crisis of energy, it is necessary time and effort for research and development of renewable energy in the future. As alternative energy, small hydropower generation which has output of less or equal to 100kW is attracting considerable attention. This is because of its small, simple, renewable, and large amount of energy resources. By using a small hydropower generator of which main concept is based on using the different water pressure levels in pipe lines, energy which was initially wasted by use reducing of a valve at the end of the pipeline, is collected by turbine in the small hydropower generator. In this study, we investigated the influence of the number of runner vanes on the characteristics of tubular-type hydroturbine.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.10
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• pp.1225-1231
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• 2014

This paper presents the performance characteristic of a Francis hydro turbine with an inline casing. This turbine is designed for city water supply system. Due to large changes in ground elevation with high points and low points, some systems may experience larger-than-normal required pressures in areas with low ground elevations. One way to dissipate these excess pressures is by the use of an inline-turbine instead of an inline-pressure reducing valve. For best applicability and minimal space consumption, the turbine is designed with an inline casing instead of the common spiral casing. As a characteristic of inline casing, the flow accesses to the runner in the radial direction, showing a low efficiency. The installation of vanes improves the internal flow and gives the positive encouragement to the output power. For the power transmission to the outside of the turbine casing from the runner axis, a belt passage is designed in the inline casing, as its influence, the region after the belt passage shows a relatively low output power. The clearance gap in the runner side space is considered, in which a small volume of flow is contracted into the clearance gap, forming the leakage flow. The leakage flow leads to a decrease in the efficiency.