• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1201-1206
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• 2003

A measurement device for gas flow rate using hot-wire module is developed for the utilization in low-accuracy industrial applications. The module has three wires of measuring and heating, and a bridge circuit is installed to detect electric current through the wire in the module. An amplification of the signal and conversion to digital output are conducted for the online measurement with a personal computer. In addition, temperature distribution in the module is numerically analyzed to examine the measured outcome from the module experiment. The flow rate of air and carbon dioxide gas is separately measured for the performance examination of the device. The experimental relation of measurement and flow agrees with the prediction from the numerical analysis. The outcome of the performance test indicates that the accuracy and reproducibility of the module is satisfactory for the purpose of industrial applications.

• Journal of Ocean Engineering and Technology
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• v.37 no.1
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• pp.8-19
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• 2023

In recent years, modular-type floating islands have been considered as a promising option for future ocean space utilization. A modular floating island consists of a number of standardized pontoon-type modules and connectors between them. In this study, the motion responses of a modular floating island in waves was investigated based on frequency-domain numerical analysis. The numerical method is based on the potential flow theory and adopts a higher-order boundary element method with Green's function. First, motion RAOs were directly compared with the model test data by reference to validate the present numerical method. Then, numerical investigations were conducted to analyze the motion characteristics of the floating island by considering various modules shapes and arrangements. It was found that motion responses were reduced in a single central module compared to when divided central modules were used. Finally, the effect of modular arrangement on the motion responses in irregular waves was discussed. It was confirmed that multiple-layer outer modules are more effective in calming the central module than using single-layer outer modules, except under very long period conditions.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.5
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• pp.102-108
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• 2013

In this study, the experiment result and numerical analysis on temperature distribution of a secondary battery module for high temperature operation type were compared. Because experimental battery has been in danger of explosions, experiment on temperature distribution was carried out using dummy batteries. Study on NAS battery module, which is secondary battery of high temperature operation type, is as follows ; Test result showed that battery's temperature is in steady state uniformly after 8 hours in each section. It is similar to experimental result for temperature distribution from the result of numerical analysis, and it takes about 8.5 hours to the $300^{\circ}C$.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.6
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• pp.811-816
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• 2011

We develop a plastic object lens for blu-ray disc playing pick-up module as morethan 0.85 numerical aperture in this research. We design plastic object lens for blu-ray disc playing pick-up module's each factor's in balanced and made our designed lens by injection molding. Furthermore, by correction designing in mold-core, we optimization our lens efficiency as world grade; wave front aberration $0.028{\lambda}$. RMS, light axis differential 0.3967arcmin. We can manufacture localized blu-ray disc's pick-up lens's component and by this fact we obtain international competitiveness. The result of this research will be very helpful to develop a single objective lens for 3 different wavelength of laser diodes in playing and recording pick-up module.

• 한국전산유체공학회:학술대회논문집
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• 2003.08a
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• pp.194-199
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• 2003

The studying is to analyze characteristic of air flow and is used to design in an automotive HVAC module. The RNG k-e turbulence model with the Upwind Difference convection scheme and an unstructured hybrid mesh with arbitrary matching method were applied to the simulation. The comparing air flow characteristic of the basic HVAC module and total HVAC module with blower were discussed in the paper.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.3
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• pp.130-138
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• 2010

The thermal reliability of the closed-type BLDC motor for the high speed axial fans is analyzed by a numerical method in this paper. Since the module and the motor part are combined in a closed case, the heat generated from a rotor in the motor and the electronic components in the PCB module can not be effectively removed to the outside. Therefore the module will easily fail by high temperature. The accelerated-life testing was accomplished to formulate the life equation and numerical method is used to predict the inside temperature of the PCB module, which is one of the life equation parameter according to the environment. When the environment temperature of BLDC motor is 21, 35 and 50 $^{\circ}C$, the temperature in the PCB space is predicted as 73.4, 87.5 and 102.4 $^{\circ}C$. Then the life time with the temperature are calculated as 2,239, 863 and 328 hours.

• Proceedings of the SAREK Conference
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• 2007.11a
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• pp.494-499
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• 2007

The thermal reliability of the closed-type BLDC motor for the high speed axial fans is analyzed by a numerical method in this dissertation. Since the module and the motor part are combined in a closed case, the heat generated from a rotor in the motor and the electronic components in the PCB module can not be effectively removed to the outside. Therefore the module will easily fail by high temperature. The accelerated-life testing was accomplished to formulate the life equation and numerical method is used to predict the inside temperature of the PCB module, which is one of the life equation parameter according to the environment. The experiment for measuring the surface heat flux of the electronic components is carried out to apply the boundary condition of numerical study. When the environment temperature of BLDC motor is 21, 35 and $50^{\circ}C$, the temperature in the PCB space is predicted as 73.4, 87.5 and $102.4^{\circ}C$. Then the life time with the temperature are calculated as 2,239, 863 and 328.

• Journal of the Korean Solar Energy Society
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• v.31 no.4
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• pp.95-102
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• 2011

In this paper, the thermal performance of a heat spreader module for CPV(Concentrating Photovoltaic) cooling is experimentally investigated. In order to evaluate the thermal performance of the heat spreader module which consists of a Metal PCB and an aluminum alloy heat spreader, experiments are conducted with varying the type of the metal PCB, the thickness of the heat spreader, the inclination angle, and the applied heat flux. To validate the experimental data, three dimensional numerical simulations are performed using the commercial simulation tool in the present work. The experimental results are compared with the corresponding numerical results and are in close agreement with the numerical results. From the experimental results, the temperature difference between the maximum temperature and the ambient temperature increases with decreasing the thickness of the heat spreader and with increasing the applied heat flux. Also, it is found that the inclination angle significantly affects the thermal performance of the heat spreader. the maximum temperature difference of the heat spreader with the horizontal orientation is much larger than that with the vertical orientation.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.3
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• pp.113-121
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• 2021

In this study, the thermal characteristics of cold and hot water mattress units equipped with thermoelectric modules were investigated via numerical analyses. Cold and hot water mattress products that are currently in existence use manual methods requiring refrigerants to be added to the hot water boiler. However, the cold and hot water mattress units using thermoelectric modules can provide improved efficiency via energy savings and actively resolving environmental pollution problems. To determine the efficiency of the thermoelectric module, the mattress was modeled and its efficiency was analyzed for the cooling and heating processes using two 100-W-class and one 200-W-class thermoelectric modules, respectively. From the results of this study, it was confirmed that when two 100-W-class modules were used, the application area was larger than when a single 200-W-class module was used, with uniform temperature distribution and improved performance compared to existing products in terms of electrical energy.

• International Journal of Automotive Technology
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• v.8 no.2
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• pp.149-154
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• 2007

The engine behavior in a transient condition is important to not only emission regulations but also fuel economy. A fast response gas analyzer can be a useful tool to investigate exhaust gas in a transient operation. It should be designed to analyze gas concentration with a short time constant by a fast sampling module and an appropriate measuring method for each emission element. In this study, a new fast sampling module is introduced and flow analysis is performed by numerical simulation. The analysis has shown the proper operating condition and the sensitivity of the module for practical application. Calculated flow to the sampling module has $0.5{\sim}4%$ error, while backflow toward the expansion tube is expected when pressure in CP (Constant Pressure) chamber is over 0.6 bar. For a stable supply of flow to the optical cell, sample gas pressure should be in the range, $0.35{\sim}1.90$ bar, when the pressure in the CP camber and the optical cell are 0.2 bar and 0.158 bar, respectively.