• Corrosion Science and Technology
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• v.18 no.1
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• pp.16-23
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• 2019

Steels for automotive fuel tank require unique properties such as corrosion resistance for fuel, welding for joining, forming for press, and painting for exterior. Recently, automakers have been requiring excellent seam weldable steels to enhance manufacturing productivity of fuel tank. Thus, POSCO developed a new type of functional steels coated with nano-composite thin layer on Zn-Ni plating steels. The nano-composite coating solution was prepared by mechanical fine dispersion of solutions consisting of polymeric resin and nano-composite materials in aqueous media. The composite solution was coated on the plating steel surface by using roll coater and cured through induction furnace. These new developed plating steels were evaluated for quality performances such as seam and spot weldability, press formability, and corrosion resistance. These new functional steels coated with nano-composite layer exhibited excellent seam weldability and press formability. Detailed discussion of coating solution and experimental results suggest that nano-sized composite dispersion as coating layer plays a key role in enhancing the quality performance.

• Journal of Aerospace System Engineering
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• v.18 no.3
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• pp.8-16
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• 2024

Because hydrogen has very low density, a different storage method is required to store the same amount of energy as fossil fuel. One way to increase the density of hydrogen is through liquefaction. However, since the liquefied temperature of hydrogen is extremely low at -252 ℃, it is easily vaporized by external heat input. When liquid hydrogen is vaporized, a self-pressurizing phenomenon occurs in which the pressure inside the hydrogen tank increases, so when designing the tank, this rising pressure must be carefully predicted. Therefore, in this paper, the internal pressure of a cryogenic liquid fuel tank was predicted according to the liquid hydrogen filling ratio. A one-dimensional thermodynamic model was applied to predict the pressure rise inside the tank. The thermodynamic model considered heat transfer, vaporization of liquid hydrogen, and fuel discharging. Finally, it was confirmed that there was a significant difference in pressure behavior and maximum rise pressure depending on the filling ratio of liquid hydrogen in the fuel tank.

• Journal of Aerospace System Engineering
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• v.1 no.4
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• pp.22-27
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• 2007

The 150 gal Ion EFT(External Fuel Tank) used to enlarge the aircraft operation range was adopted an import equipment in T-50 FSD phase. But in Production phase the EFT was planed to develop for the stable ILS(Integrated Logistics Support) and technical ability improvement by using the composite materials. The design for configuration and fuel system is intended to maintain compatibility with aircraft systems and the development test is performed on component, assembly and aircraft. This study is conducted to provide the technology of design and test for the 150 gallon composite EFT in LRU level. The test results show that the composite EFT is satisfied with structural, functional and environment requirements which are described in specification.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.5
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• pp.477-481
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• 2010

Some rotorcraft fuel tanks are required to be self-sealing and crashworthy for enhancing the survivability of crews. Self-sealing capability prevents the fuel leakage through contacting fuel with self-sealing material when the tank wall is penetrated by projectiles such as bullets. US army established MIL-DTL-27422D which specifies the detail requirements related to gunfire resistant fuel tank especially for military rotorcraft. The Fuel tanks for Korea Helicopter Program have been developed in accordance with MIL-DTL-27422D. The Self-sealing capability of the fuel tanks has been confirmed by the gunfire resistance test which specified on the MIL-DTL-27422D.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.605-611
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• 2019

The fuel sloshing due to the rapid manoeuvre of the aircraft causes significant loads on internal components, which may break components or piping. In particular, a significant load is applied to the joint of the external fuel tank by sloshing movement, which may affect the safety of the aircraft when the joint of the external fuel tank is damaged. Therefore, in order to improve the survivability of aircraft and crew members, the design of external fuel tanks, and joints should be performed after evaluating the sloshing load through a numerical analysis of the fuel sloshing conditions. In this paper, a numerical analysis was performed on the sloshing test of the external fuel tank for rotorcraft. ALE (Arbitrary Lagrangian Eulerian) technique was used, and the test conditions specified in the U.S. Military Specification (MIL-DTL-27422D) was applied as the conditions for numerical analysis. As a result of the numerical analysis, the load on the joint of the external fuel tank was calculated. Moreover, the effects of sloshing movement on structural soundness were assessed through analysis of stress levels and margin of safety on metal fittings and composite containers.

• Transactions of the Korean hydrogen and new energy society
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• v.10 no.3
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• pp.151-157
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• 1999

The development of hydrogen vehicles has been actively progressed in the developed countries such as U. S., Japan and Germany. The most important technology of using hydrogen fuel is to develope a compatible storage tank with respect to the fossil fuel tank. Among many storage methods, the liquid hydrogen is the most desirable state because of the lowest volume and weight. The metal hydride tank is too heavy and the compressed hydrogen tank is too bulky. Because of these reasons, it is the principal purpose to analyze the theoretical heat transfer for designing and manufacturing an actual $LH_2$ tank. The insulation methods of the room between inner and outer vessel are non-vacuum, vacuum, vacuum with MLI(Multi-Layer Insulation). According to the results of the numerically calculated heat leak through the walls of the $LH_2$ tank, the vacuum insulated tank has 20 times and the MLI tank has 5616 times less heat leak than the non-vacuum tank.

• Progress in Superconductivity and Cryogenics
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• v.22 no.4
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• pp.51-56
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• 2020

In order to increase thrust of the space launch vehicle, liquid oxygen as an oxidizer and kerosene or liquid hydrogen as a fuel are generally used. The oxidizer tank and fuel tanks are manufactured by composite materials such as CFRP (Carbon Fiber Reinforced Plastic) to increase pay load. The thermal stress of the cryogenic propellant tank should be considered because it has large temperature gradient. In this study, to confirm the design integrity of the oxidizer tank of liquid oxygen, a numerical analysis was conducted on the thermal stress and temperature distribution of the tank for various charging speed of the cryogenic fluid from 100 ~ 900 LPM taking into account the evaporation rate of the liquid nitrogen by convective heat transfer outside the tank and boiling heat transfer inside the tank. The thermal stress was also calculated coupled with the temperature distribution of the CFRP tank. Based on the analysis results, the charging speed of the LN2 can majorly affects the charging time and the resultant thermal stress.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.494-500
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• 2007

The comfort and quietness of vehicle has been improved greatly due to the development of technology in automobile industry. It is driven by reduction on the level of vibration and noise in powertrain system. However, the hidden problems in automobile parts become noticeable since the vehicle has been better in overall performance. One of them is related to the fuel pump system. Therefore, this study is focused on investigating the characteristics of fuel pump and fuel tank first, and then comparing the data before and after installation of fuel pump system in a testing vehicle. Additionally, the measured data will be analyzed to identify the problems and find a solution to improve the level of noise and vibration in fuel pump system.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.8
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• pp.585-592
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• 2007

Good cold start characteristics are essential for satisfactory operation of fuel cell vehicles. In this study, the melting process has been numerically investigated for a water tank used in fuel cell vehicles. The 2-D model of the tank containing ice and plate heaters was assumed and the unsteady melting process of the ice was calculated. The enthalpy method was used for the description of the melting process, and a FVM code was used to solve the problem. The feasibility study compared with other experiment showed that the developed program was able to describe the melting process well. From the numerical analysis carried out for different wall temperatures of the pate heaters, some important design factors could be found such as local overheating and pressurization in the tank.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.8
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• pp.806-812
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• 2010

Fuel tanks for rotorcraft have a great influence on the survivability of crews. The philosophy of crashworthy rotorcraft design evolved from the long term effort of the US Army. US army established MIL-DTL-27422D for specifying detail requirements related to crash resistant fuel tank especially for military rotorcraft to prevent post crash fire which is the greatest threat to life in rotorcraft crash. Crashworthiness of the rotorcraft fuel tank could be guaranteed through the crash impact tests which are specified in the MIL-DTL-27422D. Fuel tanks for Korea Helicopter Program have been developed and tested according to MIL-DTL-27422D with minor modifications of flexible fittings. The present study shows some results of the mandatory crash impact tests of the fuel tanks to verify their performances.