• Textile Coloration and Finishing
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• v.16 no.3
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• pp.31-38
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• 2004

Polyester fabrics, which is a major product in Daegu and Kyungbuk district, recently have a frequent warp streak phenomenon of sizing textiles for peach skin. So, this paper intensively focuses on the analysis of finding causes of poor products which may be produced in the process of sizing. Depending on the changes of sizing yarn's physical characteristic varying on sizing conditions, results of the research are as followed. 1. Sizing add-on rate, following tension changes of originally supplied yarn in sizing, does not fluctuate until 30g sizing tension, but marks high on the increase of sizing speed. 2. Sizing add-on amount increases approximately by 2.5% when interlacing pressure is raised from 1.5kg/$cm^2$ to 3.5kg/$cm^2$ at $130^{\circ}C$ sizing temperature. 3. Following the increase of sizing tension from 10g to 50g, boiling shrinkage rate of desizing yarn changes approximately from 7% to 11%. But the more sizing temperature and speed increases, the bigger the change rate becomes. 4. The thermal stress of desizing yarn is sensitively influenced by sizing tension in the sizing degree of above $130^{\circ}C$. 5. The deviation rate of sizing yarn's initial modulus value, which is influenced by air pressure in interlacing raw yarn, marks the highest at 40g and 50g strength.

• Nuclear Engineering and Technology
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• v.53 no.11
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• pp.3643-3652
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• 2021

Sizing the tube inlet orifice of a Once-Through Steam Generator (OTSG) is important to protect the integrity of the tubes from thermal cycling and vibration wear. In this study, a new sizing criterion is proposed for the tube inlet orifice to suppress the parallel channel instability in an OTSG. A perturbation method is used to capture the essential parts of the thermal-hydraulic phenomena of the parallel channel instability. The perturbation model of the heat transfer regime boundaries is identified as a missing part in existing models for sizing the OTSG tube inlet orifice. Limitations and deficiency of the existing models are identified and the reasons for the limitations are explained. The newly proposed model can be utilized to size the tube inlet orifice to suppress the parallel channel instability without excessive engineering margin.

• Nuclear Engineering and Technology
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• v.54 no.6
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• pp.2262-2275
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• 2022

The Korea Atomic Energy Research Institute (KAERI) studied the sodium-water reaction (SWR) minimized steam generator for the safety of the sodium-cooled fast reactor (SFR), and selected the copper bonded steam generator (CBSG) as the optimal concept. This paper introduces the conceptual design of the CBSG and the development of the CBSG sizing analyzer (CBSGSA). The CBSG consists of multiple heat transfer modules with a crossflow heat transfer configuration where sodium flows horizontally and water flows vertically. The heat transfer modules are stacked along a vertical direction to achieve the targeted large heat transfer capacity. The CBSGSA code was developed for the thermal-hydraulic analysis of the CBSG in a multi-pass crossflow heat transfer configuration. Finally, we conducted a preliminary sizing and rating analysis of the CBSG for the trans-uranium (TRU) core system using the CBSGSA code proposed by KAERI.

• Journal of computational fluids engineering
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• v.12 no.3
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• pp.62-68
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• 2007

A conceptual thermal design is performed for the optical payload system of a geostationary satellite. The optical payload considered in this paper is GOCI(Geostationary Ocean Color Imager) of COMS of Korea. The radiative thermal control system is employed in order to expect a small thermal gradient in the telescope structure of GOCl. Two design margins are applied to the dedicated radiator dimensioning, and three kinds of configuration to the heater power sizing. A Monte-Carlo ray tracing method and a network analysis method are utilized to calculate radiative couplings and thermal responses respectively. At the level of conceptual design, sizing thresholds are presented for the radiator and heater on the purpose of determining the mass and power budget of the spacecraft.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.10a
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• pp.558-563
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• 1997

A thermal sizing code, named as HSGSA (Helical coil Steam Generator Sizing Analyzer), for a sodium heated helical coil steam generator is developed for KALIMER (Korea Advanced LIquid MEtal Reactor) design. The theoretical modeling of the shell and tube sides is described and relevant correlations are presented. For assessment of HSGSA, a reference plant design case is compared to the calculational outputs from HSGSA simulation.

• Proceedings of the Korean Nuclear Society Conference
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• 2005.10a
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• pp.554-555
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• 2005

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.5
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• pp.88-94
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• 2012

Development trend of modern HSDI diesel engine is now focusing on low fuel consumption and emission because of strong interest in global environmental protection. Two big branches of criteria for modern diesel engine development are down sizing and down speeding. Down sizing keeps engine operation condition to the direction of higher load and thus pursuing for better thermal efficiency. But this may cause degraded vehicle dynamic performance because of reduced back up torque. Down speeding keeps engine operation condition to the direction of slightly higher load and lower engine speed. Therefore reduction of back up torque can be limited within flat torque area. This study analyzed fuel economy effect of down speeding on a vehicle powered by HSDI diesel engine in aspect of engine friction work, intake and exhaust pumping work, exhaust hat loss and thermal loss of fuel leakage of fuel injection system. Contribution factor of each engine and vehicle related parameters under basic and down speeding condition were compared and work balance of down speeding during NEDC was analyzed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.10a
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• pp.139-143
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• 2001

In manufacturing process of semiconductor package, thermal stress owing to high temperature in moulding and bubbles generated in chip bonding process become main causes to producing void. Therefore, on this study we evaluated quantitatively void size by ultrasonic spectroscopy method which analyze the frequency of this received pulse using pulses with broad band frequency, and after destructive test we verified effectiveness of sizing void by ultrasonic spectroscopy as we find error degree between the real size of void and the sizing void by ultrasonic spectroscopy.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.3
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• pp.182-190
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• 1993

In manufacturing process of semiconductor package, the thermal stress owing to high temperature in moulding and the bubbles generated in chip bonding process become main causes to produce void. On this study we evaluated quantitatively void size by use of ultrasonic spectroscopy method which analyze the reflective pulses with broad band frequency in frequency domain, and after destructive testing we verified effectiv- eness of sizing void by use of ultasonic spectroscopy.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.1
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• pp.97-104
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• 2014

In this study, preliminary thermal sizing was performed with the aim of developing a fuel supply and cooling system design to solve the heating problems in high-speed vehicles. First, an analysis model was used to satisfy an optional mission profile. The heat loads were computed under boundary conditions. The results were verified using the precedent design case. Then, fuel consumption rates were estimated for the analysis trajectory. Accordingly, the cooling capacity in the system was calculated using the heat sink capacity of the endothermic fuel. Lastly, the fulfillment of the design requirements was confirmed in comparison to the cooling needs.