• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.197-200
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• 2006

The portion of thin plate is expected to increases as to the development of design and fabrication technology. The weld-induced deformation is more serious in thin plates than in thick plates because heat affect zone of thin plates is wider than that of thick plates, and in addition internal and external constraints much more influence upon weld-induced deformation of thin plates. This paper deals with the application of the mechanical tensioning method to fillet weld of thin plates to reduce the weld-induced deformation. For this, fillet welding test have been carried out for several thin plate specimens with varying plate thickness and magnitude of tensile load. From the present study, it has been found that the tenssoning method is effective on reduction of weld-induced deformation.

• Journal of the Society of Naval Architects of Korea
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• v.44 no.6
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• pp.590-597
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• 2007

The portion of thin plate is expected to increases as to the development of design and fabrication technology. The weld-induced deformation is more serious in thin plates than in thick plates because heat affect zone of thin plates is wider than that of thick plates, and in addition internal and external constraints much more influence upon weld-induced deformation of thin plates. This paper is aimed at applying the mechanical tensioning method to fillet weld of thin plates to reduce the weld-induced deformation. For this purpose, fillet welding tests have been carried out for several thin plate specimens with varying plate thickness and magnitude of tensile load. From the present study, it has been found that the tensioning method is effective on reduction of weld-induced deformation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.1
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• pp.69-73
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• 2013

Internal heat exchanger (IHX) apparatus using the temperature difference between high and low pressure lines in vehicle air conditioning system is a good method to enhance the cooling performance. In this study, we designed various double-pipe internal heat exchangers which have inner fins between the internal pipe and external pipe. We also measured the performance characteristic (pressure drop, cooling capacity, compressor work and coefficient of performance (COP)) of the modified internal heat exchangers that had the change of the fin height and the inside shape of the internal pipe. This experimental results indicated that the liner and serration type internal heat exchanger was the best cooling performance. In addition, the air conditioning system with the liner and serration type internal heat exchanger showed the improved performances of about 6.4% and 9.2%, respectively, for the cooling capacity and COP.

• Journal of computational fluids engineering
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• v.13 no.2
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• pp.48-54
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• 2008

COMS (Communication, Ocean and Meteorological Satellite) is a geostationary satellite and has been developing by KARI for communication, ocean and meteorological observations. It will be launched by ARIANE 5. Ka-band components are installed on South panel, where single solar array wing is mounted. Radiators, embedded heat pipes, external heat pipe, insulation blankets and heaters are utilized for the thermal control of the satellite. The Ka-band payload section is divided several areas based on unit operating temperature in order to optimize radiator area and maximize heat rejection capability. Other equipment for sensors and bus are installed on North panel. The ocean and meteorological sensors are installed on optical benches on the top floor to decouple thermally from the satellite. During the transfer orbit operation, satellite will be under severe thermal environments due to low dissipation of components, satellite attitudes and LAE(Liquid Apogee Engine) firing. This paper presents temperature and heater power prediction and validation of thermal control design during transfer orbit operation.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.433-442
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• 1993

Coolstore air relative humidity (RH) is an important factor affecting the quality of horticultural products, particularly via product moisture loss. RH also has an important effect on the performance of the refrigeration evaporators and can affect the strength of paper-based packaging materials. In a large New Zealand apple coolstore, RH increased from about 75% early in season to 90% at the end, as activities in the coolstore and external conditions changed. A steady-state analysis of sensible and latent heat entry and heat removal during four typical operational periods over the season was carried out. Predicted RH was in good agreement with measured dat. For the coolstore studied, evaporator surface area and the occurrence of pre-cooling within the coolstore were the design and operational factors having greatest effect on RH. Door protection and management, and floor insulation were the next more significant factors. The method of analysis has more general application and ould be used in a variety of situations so that design for optimum RH can be performed systematically.

• 한국전산유체공학회:학술대회논문집
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• 2007.10a
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• pp.227-231
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• 2007

COMS (Communication, Ocean and Meteorological Satellite) is a geostationary satellite and has been developing by KARI for communication and ocean and meteorological observations. It will be launched by ARIANE 5. Ka-band components are installed on South panel, where single solar array wing is mounted. Radiators, embedded heat pipes, external heat pipe, insulation blankets and heaters are utilized for the thermal control of the satellite. The Ka-band payload section is divided several areas based on unit operating temperature in order to optimize radiator area and maximize heat rejection capability. Other equipment for sensors and bus are installed on North panel. The ocean and meteorological sensors are installed on optical benches on the top floor to decouple thermally from the satellite. During the transfer orbit operation, satellite will be under severe thermal environments due to low dissipation of components, satellite attitudes and LAE(Liquid Apogee Engine) firing. This paper presents temperature and heater power prediction and validation of thermal control design during transfer orbit operation.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.79-80
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• 2016

In the event of a fire on the outer walls of an architectural structure, through real scale experiments with the purpose of estimating the Flame Trajectory, the behavior and risks of expanded combustion to an upper architectural compartment of the Fire Plume Ejected from an Opening according to changes in the aspect ratio of the opening were examined. The results showed that the more the heat release rate of the fire source increased, the heat capacity of the Fire Plume Ejected from the Opening also increased, and for the case of heptane when compared with methanol or ethanol, the results showed a trend for a significant amount of unburned gas to remain. The results also showed that the larger the aspect ratio was, the more likely it was for the Flame Trajectory to approach the outer walls and rise up. In each of the experiment conditions, as the flame rose from the lower part of the wall to the upper part of the wall, a steady decrease was shown for the temperature distribution. Also by quantitatively analyzing the amount of unburned gas that remained, a method to estimate the temperature of the Fire Plume Ejected from an Opening for a traverse opening was implemented.

• Fire Science and Engineering
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• v.26 no.4
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• pp.18-23
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• 2012

After produce the extracted wood to silicic acid gel, sodium carbonate and silicon dioxide with application of the making method for carbon dioxide, ignition time, ignition temperature, mass loss rate and critical heat flux are measured according to external radiation source (20, 25, 35 and 50 $kW/m^2$). From the results, pressure impregnation wood to use with water glass and carbon dioxide has fire retardant performance at heat flux (less than 20 $kW/m^2$) of Pre-Flashover fires. If we find out the excellent maxing ratio through continuously study, it might be decided to be able to be utilized as fire-retardant wood.

• Journal of Physiology & Pathology in Korean Medicine
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• v.36 no.5
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• pp.147-154
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• 2022

In order to secure practising rapid pattern(證, zheng) differentiation against acute infectious diseases like corona virus disease-19(COVID-19) showing rapid variation and contagion, a simplified classification of stages centering on the exterior-interior pattern identification with 2 step-subdivision by cold, heat, deficiency, excess pattern and pathogens is proposed. Pattern differentiation by compound patterns of 8 principles is made for the non-severe stage of general cold and the early mild stage of epidemic disease. Compound pattern's names of 8 principles about external infectious diseases are composed of three stages, that is disease site-characters-etiology. Based on early stage symptoms of fever or chilling etc., exterior, interior and half exterior and half interior patterns are determined first, and then cold, heat, deficiency, excess patterns of exterior and interior pattern respectively are determined, and then more concrete differentiation on pathogens of wind, dryness, dampness and dearth of qi, blood, yin, yang accompanied with constitutional and personal illness factors. Summarizing above descriptions, 4 patterns of exterior cold, exterior heat, exterior deficiency, exterior excess and their secondary compound patterns of exterior cold deficiency and exterior cold excess and so on are classified together with treatment method and available decoction for a standard measure of eight principle pattern differentiation.

• Tribology and Lubricants
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• v.32 no.1
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• pp.1-8
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• 2016

This paper focuses on the thermal deformation induced preload change in the tilting pad journal bearing, using a three-dimensional (3D) thermo-hydro-dynamic (THD) approach. Preload is considered as a critical factor in designing the tilting pad journal bearing. The initial preload measured under nil external load and nil thermal gradient is influenced by two factors, namely, the thermal deformation and elastic deformation. Thermal deformation is due to a temperature distribution in the bearing pads, whereas the elastic deformation is due to fluid forces acting on the pads. This study focuses on the changes induced in preload and film clearance due to thermal deformation. The generalized Reynolds equation is used to evaluate the force of the fluid and the 3D energy equation is used to calculate the temperature of the lubricant. The abovementioned equations are combined by establishing a relationship between viscosity and temperature. The heat transfer within the bearing pads, the lubricant, and the spinning journal is calculated using the heat flux boundary condition. The 3D Finite Element Method (FEM) is used in modeling the (1) heat conduction in the spinning journal and bearing pads, (2) thermal gradient induced thermal distortion of the spinning journal and pads, and (3) viscous shearing, and heat conduction and convection in a thin film. This evaluation method has an increased fidelity, and it can prove to be a cost-effective tool that can be used by designers to predict the dynamic behavior of a bearing.