• Proceedings of the KSR Conference
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• 2000.05a
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• pp.634-644
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• 2000

The study was carried out about the roof hood structure of power car for Korean High Speed Train. The compatibility for applied material and volume of hood duct was studied using analysis about heat and flow distributions. The materials and volume of duct were mainly determined by output air temperature and flow rate of each electric blocks. This report was described, which focuses on pressure distribution and air temperature within engine compartment of power car.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.1 s.173
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• pp.62-68
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• 2000

Optimization technique to find a path of an inner reinforcement of an automobile hood is proposed by using design sensitivity informations. The strength and modal characteristics of the automobile hood are analyzed and their design sensitivity analyses with respect to the thickness are carried out using MSC/NASTRAN. Based on the design sensitivity analysis, determination of design variables and response functions is discussed. Techniques improving design from design sensitivity informations are suggested and the double-layer method is newly proposed to optimize the path of stiffener for a shell structure, Using the suggested method, we redesign a new inner reinforcement of an automobile hood and compare the responses with the original design. It is confirmed that new design improved in the frequency responses without the weight increasement.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.5
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• pp.66-72
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• 2014

A kinematic analysis method has been used as analysis method for dynamic behavior of moving parts of vehicle, especially hood part. Such analysis method, however, has its limitations in terms of design technology, including, over travel of hood that occurs due to lack of considerations of compliance characteristics, such as flexible components of hood's weather strip and over slam bumper. Therefore, it is necessary to develop a modeling which reflects compliance of flexible components of hood and elastic characteristics of panel for improvement of design process. In this thesis, a finite element method as mentioned earlier, is developed to represent over travel of hood. Also optimization process applying sequential approximate optimization is suggested to prevent over travel. The over travel analysis method and optimization process, which are developed through the research, would make it possible to design with high quality and credibility. Furthermore, it is expected that the time for design would be reduced and the design quality also improved.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.220-226
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• 2005

To achieve the weight reduction of a vehicle, Magnesium alloys are widely used in automobile parts because of its lightweight characteristics. Magnesium alloys also have advantages in recycling, stiffness, NVH , heat protection. But Magnesium alloy parts are mainly manufactured by diecasting processes, their productivity was not so high compared to by sheet metal working. We are developing vehicle hood using magnesium sheets. In this study we designed magnesium alloy hood which have equivalent mechanical characteristics to steel hood. Using finite element method we decided thickness of magnesium sheets under some design requirements and we changed the shape of hood inner panel and hinge reinforcements. Outer and inner panel thickness was 1.3mm, 1.5mm respectively. Panel dentibility analysis was performed to conform the new magnesium design by nonlinear FEM package. Formability and hemming of Magnesium sheets are the subjects for further study because they have poor stretchability compared to steel sheets.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.12
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• pp.594-599
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• 2014

There have been many cases that the air curtain installed in the apartment can not well remove the gases such as carbon dioxide and particles such as smokes, oils and vapors generated during the cooking to disperse the pollutants into the room. This study uses the numerical analysis to show how the pollutant-removing performance of the range hood is changed when the air curtain is installed on the range hood of kitchen. As a result of the study, it turned out that, when the air amount supplied by air curtain through the slot was about 60% of exhaust amount, the capturing efficiency of range hood for pollutants increased by 70~80% more than the case without the air curtain. Even when the exhaust amount was small, the capturing efficiency was improved a lot with the use of air curtain. In case that the air flow velocity of slot was greater than 2 m/s, the capturing efficiency turned out to decrease.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.16 no.2
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• pp.61-67
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• 1980

Previously, we had experimented on the model of stow net under the various combination including water velocity, spherical floats and elevating floats with the shearing hoods instead of the upper beam, however we couldn't concern with their characteristics. Spherical floats maintain their buoyancy at the same level when the speed increases, only the drag increases and effects some reduction in the fishing height. To eliminate this shortcoming, floats have to some hydrodynamic lifting force which increases with increasing speed. Phillips float with a dish-shaped metal plate welded on at the lower part and synthetic upthrusting float were used for the experiment to compare with their characteristics. Six kinds of model shearing hood depend on the angle of attack were used to test the characteristic of the shearing hood. According to their results, when the angle of attack is 30\ulcorner, the lift and drag coefficient reveal 1. 36, 0.84 respectively. And also experimented on the 5X8cm shearing hood to investigate the suitability for the model stow net.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.1
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• pp.593-601
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• 2014

In this study, we investigated the methods of improving the capturing ability of acid fume by assessing the performance of slot-type external hood installed on both sides of an open surface tank for acid washing process. A field survey and the results of computational fluid dynamics revealed that capturing performance of existing hoods is very poor. To solve such problem, 'push-pull hood' that pushes from one side of an open surface tank and pulls on the other side was suggested. The initial prediction was that if a push-pull hood is used, the acid fume of an acid-washing tank surface could be moved towards the hood through the push flow. However, this study has confirmed that if the push flow velocity becomes too high, it could spread to other areas due to flooding from the hood. Therefore, if the push air supply is maintained at around 25 $m^3/min$(push 10 m/s), proper control flow is formed on the surface of a tank and acid fume that stayed at the upper part of the tank is smoothly captured toward the hood, significantly enhancing the capturing performance.

• Journal of Positioning, Navigation, and Timing
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• v.3 no.2
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• pp.63-69
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• 2014

In this study, due to the necessity of the equipment for inspecting an anti-jamming function depending on the expansion of the development of anti-jamming systems, an array antenna hood that can inspect the anti-jamming function of an anti-jamming system while being installed at the system was designed and manufactured. The manufactured array antenna hood plays a role in radiating GNSS signals and jamming signals. Based on an experiment, it was demonstrated that using a near-field radiation method, the manufactured array antenna hood could be used for examining the normal operation of an anti-jamming system function in outdoor or indoor environments rather than an anechoic chamber.

• Proceedings of the KSR Conference
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• 1999.05a
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• pp.406-413
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• 1999

A compression wave is generated by the high speed train which enters a tunnel, and it propagates along the tunnel. When the compression wave emerges from the exit of the tunnel, it causes an impulsive noise, and the strength of the impulsive noise depends on the pressure gradient of the first compression wave. So it needs to reduce the pressure gradient for the minimization of impulsive noise. The entrance hood is used for the reduction of the pressure gradient. In the present study, the pressure transients were numerically calculated for three shapes of hood, In order to validate the numerical simulation, the pressure and pressure gradient were compared with the experimental data of moving model rig. The calculation results won well agreed with the experimental data, and also showed that the hood had an effect on the pressure gradient of the tunnel inside.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.12
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• pp.489-494
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• 2016

There have been many cases when an air curtain installed in the apartment could not remove the gases well, such as carbon dioxide and particles like as smoke, oils, and vapors generated during cooking to disperse pollutants into the room. This study used a numerical analysis to show how the pollutant-removing performance of the range hood is changed when the air curtain is installed front of the kitchen table. The result of this study was that when the air amount supplied by an air curtain through the slot was about 50% of the exhaust amount, the capturing efficiency of the range hood for pollutants increased 90% more than without an air curtain. Even when the amount of supplied air was small, the capturing efficiency improved markedly with the use of an upward air curtain. In case that the air flow rate of the slot was greater than 60%, the capturing efficiency decreased.