• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.713-716
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• 2010

Slosh and vibration effects of fuel inside of fuel tank can be occurred due to the acceleration and flight speed during the rotorcraft flight. It can lead to the failure of internal fuel component and fuel tank skin can be damaged. This is directly related to human survival. Military specification (MIL-DTL-27422D) specifies that stability of aircraft fuel tank and internal component against slosh &vibration load shall be verified through the qualification test procedures. This report shows the establishment of slosh and vibration test facility and KUH fuel tank qualification test result.

• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.1
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• pp.1-6
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• 2012

This study is damage evaluation for CNG fuel tank during the burst test through the analysis of acoustic emission signals. Kaiser effect until the pressure 420 bar appears, but More than 420 bar by the creep effect appears significantly damaged vessels, and 480 bar pressure, the Kaiser effect of the rising phase was missing. Resonant transducer at 540 bar than 480 bar decreased activity such as energy and count Continually, but increased wideband transducer. In addition, through the rise time or frequency analysis of composite pressure vessels in order to observe the damage mechanisms wideband transducer is more effective than resonant transducer.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.9
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• pp.1131-1136
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• 2011

This study is performed on the acoustic emission parameters involved in a burst test for a CNG-vehicle fuel tank. A resonant AE sensor with a central frequency of 150 kHz was attached on the composite materials in the center of the fuel tank. The analysis of AE parameters such as hit, amplitude, count, duration, risetime, and signal strength during load holding was performed. The total count and total signal strength are effective tools for the damage evaluation of a CNG fuel tank.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.5
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• pp.566-575
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• 2011

Since LPG (Liquefied petroleum gas) fuel supply system has an advantage of low emission characteristics, many studies have been conducted. In spite of the advantage of LPG supply system, a higher vapor pressure and lower viscosity than diesel or gasoline fuel may cause unstable running of fuel pump by the deterioration in lubrication performance and chemical reaction with rubber parts than that of diesel and gasoline fuel. Therefore its physical properties can cause the deterioration of durability. In this research, we developed an external type LPG pump which has the advantage of the price competitiveness and the convenient maintenance for LPLi system. The experiments were carried out in order to assess characteristics of the external type fuel pump at different fuel composition and temperature. As a result, there aren't any differences between internal and external type pump performance. It is observed that the same level of efficiency was maintained for both pumps as flow rate was increased with higher fuel temperature and more contents of propane in the fuel. And the pressure difference in LPLi system is maintained at constant with the various fuel compositions and temperatures due to their own characteristics of fuel supply system.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2016.10a
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• pp.185-186
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• 2016

• Journal of Astronomy and Space Sciences
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• v.19 no.3
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• pp.207-214
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• 2002

One of the way to derive design parameters of the fuel feeding system in satellite propulsion system is to analyze unsteady flow of liquid propellant (hydrazine). During steady thruster firing the flow rate is constant: if a thruster valve is abruptly shut down among a set of thrusters, pressure spikes much higher than the initial tank pressure occur. This renders the fuel flow unsteady, and the fluid pressure and flow rate to oscillate. If the pressure spikes are high enough, there are possibilities that propellant explosively decomposes, thruster valves we damaged, and adiabatic detonation of the hydrazine propellant is potentially incurred. Reflected shockwaves could also affect the calibration and operation of the pressure transducers. These necessitate the analysis of unsteady flow in the propulsion system design, and pressure behavior inside the propellant line obtained through some governing parameter variation is presented in this work.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.05a
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• pp.100-109
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• 2006

In the regeneratively cooled combustion chambers using hydrocarbon fuels, coking occurs as the wall temperature increases which generates compounds deposition on the wall. This phenomenon reduces cooling capability of the coolant, finally it can cause damage to combustor by overheating of chamber wall. In this paper electrical heating equipment which is used for the coking experiments and the test results are introduced. The compatibilities of copper alloy with let A-1 were assessed at each condition based on the test results.

• Journal of the Korean Society of Propulsion Engineers
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• v.11 no.5
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• pp.78-84
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• 2007

In the regeneratively cooled combustion chambers of liquid rocket engine using hydrocarbon fuels, coking occurs as the wall temperature increases which results in compounds deposition on the wall of cooling channels. This phenomenon reduces cooling capability of the coolant which finally causes damage to the combustor by overheating of the chamber wall. In this paper, experiment results using an electrical heating equipment to simulate the regeneratively cooled channel are introduced and based on the results the compatibility of copper alloy with hydrocarbon fuel Jet A-1 is investigated.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.6
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• pp.579-582
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• 2012

Removing residual water in a fuel cell is a critical operational process for managing its performance and controlling its lifetime. Understanding the mechanism of water transport in fuel cells is essential for the design of the water removal process. In this study, an experimental method for measuring the water evaporation rate through a gas diffusion layer, which is a porous medium, under steady-state conditions was developed. Experimental bench tests were conducted to apply the developed method. Then, the effects of various parameters of the drying gas and the gas diffusion layer were experimentally measured. The water evaporation rate increased as the humidity of the drying gas decreased and the flow rate of the drying gas increased. In addition, a thinner gas diffusion layer yielded a higher water evaporation rate.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2005.11a
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• pp.353-357
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• 2005

LOx post damage occurs from the development process of the full-scale gas generator which is necessary to 30 tonf class engine development was described. The cause and analysis for damage was described. The combustion test result of 4 injector, the full-scale gas generator and redesigned injector was described. Combustion instability, purge, the low momentum of LOx spray, small recess number, the low flow of LOx, and the high spray angle is main reason the possibility of knowing. The redesign for the injector in the direction of increase of recess number, increase of LOx and fuel spray angle, decrease of gap interval between the LOx post outer wall and fuel screen and increase of LOx post wall thick became accomplished.