• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2004.04a
• /
• pp.71-74
• /
• 2004

A composite-aluminum hybrid joint of composite external fuel tank of an aircraft has been analyzed by a 3-dimensional finite element method. Curvature and contact of the joint structure were considered in the analysis. Yamada-Sun failure criteria was utilized for the failure evaluation. A finite element program ABAQUS was used for the nonlinear contact analysis. The joint structure was predicted to be safe in both the test and analysis.

• Journal of Aerospace System Engineering
• /
• v.1 no.4
• /
• pp.22-27
• /
• 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 Aerospace System Engineering
• /
• v.16 no.1
• /
• pp.104-109
• /
• 2022

The bomb rack unit (BRU) installed inside the pylon serves to fix external attachments such as external fuel tank or external weapon, and also serves to separate external attachments in case of emergency. In particular, the load generated when the external attachment is separated from the BRU is called the punching load. In this study, we present the results of a structural static test performed to verify the structural integrity of the pylon under the BRU punching condition acting on it. In the structural static test report, we present the implementation method for the separation load of the external attachment and the test profile for the BRU punching load condition, and compared the error between the load input signal and the feed-back signal to determine the appropriateness of load control in each test. Furthermore, we compared the strain results obtained in the numerical analysis and structural test at the main positions of the specimen. As a result, it was shown that the load of the actuators were properly controlled within the allowable error range in each test, and the numerical analysis effectively predicted the test result. Finally, through structural static tests conducted by design limit load and design ultimate load, we verified that the aircraft pylon dealt with in this study has sufficient structural strength for external attachment separation condition.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.32 no.5
• /
• pp.24-29
• /
• 2004

In this paper, we summarize the results of free drop wind tunnel test, separation analysis and flight test in order to verify the safety during the separations of an external fuel tank and the LAU-131 rocket launcher from XKO-l. The wind tunnel test was conducted to show the safety in free drop of the stores and to gather the trajectory data for fine tune of MSAP(Multi-body Separation Analysis Program). The enhanced MSAP was then used to predict the trajectories of the stores with and without the ejector forces. A correlation of MSAP results for free drop case was also made to show the safety of jettison with the free drop type bomb rack. Moreover, the flight test was conducted. and its results were compared to analysis results. Finally, the safe jettison boundary was determined from the flight test.

• Journal of the Korean Society of Safety
• /
• v.29 no.6
• /
• pp.62-67
• /
• 2014

This study was performed to analyze the vulnerability of the situation in which combat system is shot by external projectile impacts. In developing combat system, it is vital to consider the survivability as well as its mission capability because it is directly connected with loss of lives. Especially, when the parts which are susceptible to fire are shot under battle situation, the system is exposed to the dangerousness and the situation when the parts such as fuel tanks are impacted by external projectile impacts can lead to flash fire as a result of the leakage of fuel. Therefore, in this study the possibility of flash fire was calculated by analyzing a variety of variables supposing that fuel tank in the combat system is shot. The aim of this study is to suggest effective methods in the basic steps when combat system is designed.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.35 no.1
• /
• pp.73-78
• /
• 2007

The process and results of Captive Flight Test(CFT), conducted by Agency for Defense Development(ADD) using the Korean KTX-1 trainer and external fuel tank, are presented. Through over 150 sorties of CFT, the guided weapon system's critical subsystems like Seeker, Navigation Device and Technology, Inertial Sensor, and Radio Altimeter are tested and evaluated. Using the CFT, time and cost are saved in weapon system research and development procedure.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.37 no.10
• /
• pp.1010-1016
• /
• 2009

In this paper, we have described an aircraft captive flight test for the development test of weapon systems. We have conducted a captive flight test for the development of core onboard parts and sensors of airborne weapons and guided missiles. We have used KTX-1/XKO-1 aircraft as a platform for the captive flight test. In order to perform a captive flight test, we have made a captive test pod as a shape of external fuel tank in the XKO-1 and have modified XKO-1 aircraft for a system interface. We have taken a development test about all kinds of seekers, navigation & guidance systems, and core part of guided missile through the aircraft captive flight test.

• Journal of Advanced Marine Engineering and Technology
• /
• v.40 no.3
• /
• pp.174-179
• /
• 2016

To protect the ocean environment, the use of liquefied natural gas (LNG) carriers, bunkering ships, and fueled ships is increasing. Recently, Korean shipbuilders have developed and supplied a partial reliquefaction facility for boil-off-gas (BOG). Despite reasonable insulation, heat leakage in vessel storage tanks causes LNG to be continuously evaporated as BOG. This research analyzed the maximum liquid yield rate for various partial reliquefaction systems (PRS) and considered related factors affecting yields. The results showed a liquid yield of 48.7% from an indirect PRS system (heat exchanges between cold flash gas and compressed natural gas), and 41% from a direct PRS system (BOG is mixed with flash gas and discharged from a liquid-vapor separator). The primary factor affecting liquid yield was heat exchanger effectiveness; the exchanger's efficiency and insulation characteristics directly affect the performance of BOG reliquefaction systems.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2017.05a
• /
• pp.942-944
• /
• 2017

High-speed vehicles are subjected to complex loads, such as acoustic pressure from the engine at launch and aerodynamic heating and aerodynamic pressure during flight. A thermal protection system panel is required to protect internal systems such as the fuel tank of the vehicle from the external environment. This study defines analytical models for heat transfer and thermal structure characteristics of the thermal protection system panel. Furthermore, the study performed parameters analysis to achieve the thermal structural integrity and to make it lighter.