• Nuclear Engineering and Technology
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• v.46 no.1
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• pp.73-80
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• 2014

A concrete cask is an option for spent nuclear fuel interim storage. A concrete cask usually consists of a metallic canister which confines the spent nuclear fuel assemblies and a concrete overpack. When the overpack undergoes a missile impact, which might be caused by a tornado or an aircraft crash, it should sustain an acceptable level of structural integrity so that its radiation shielding capability and the retrievability of the canister are maintained. A missile impact against a concrete overpack produces two damage modes, local damage and global damage. In conventional approaches [1], those two damage modes are decoupled and evaluated separately. The local damage of concrete is usually evaluated by empirical formulas, while the global damage is evaluated by finite element analysis. However, this decoupled approach may lead to a very conservative estimation of both damages. In this research, finite element analysis with material failure models and element erosion is applied to the evaluation of local and global damage of concrete overpacks under high speed missile impacts. Two types of concrete overpacks with different configurations are considered. The numerical simulation results are compared with test results, and it is shown that the finite element analysis predicts both local and global damage qualitatively well, but the quantitative accuracy of the results are highly dependent on the fine-tuning of material and failure parameters.

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

• Advances in aircraft and spacecraft science
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• v.10 no.4
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• pp.317-334
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• 2023

This paper presents a basic methodology and a set of numerical tools for the preliminary design of solid-fueled ramjet missiles. An elementary code determines the baseline system configuration comprised of warhead, guidance-control, and propulsion masses and geometries from specific correlations found in the literature. Then, the system is refined with the help of external and internal ballistics codes. Equations of motion are solved for the flight's ascending, cruising, and descending stages and the internal ballistic set of equations designs the ramjet engine based on liquefying fuels. The combined tools sized the booster and the ramjet sustainer engines for a long-range missile, intended to transport 200 kg of payload for more than 300 km range flying near 14,000 m altitude at Mach 3.0. The refined system configuration had 600 mm in diameter and 8,500 mm in length with overall mass of 2,128 kg and 890 kg/m3 density. Ramjet engine propellant mass fraction was estimated as 74%. Increased missile range can be attained with paraffin-polyethylene blend burning at near constant regression rate through primary air mass flow rate control and lateral 2-D air intakes.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.3
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• pp.474-481
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• 2011

The Electronic Warfare Computer for the Aircraft Survivability Equipment will improve the ability for countermeasures by analysis about threat information. This paper suggests method that threat data integration of multiple sensors(Radar Warning Receiver, Laser Warning Receiver, Missile Warning Receiver). The algorithm of threat data integration is based on detected threat sequence and azimuth information. The threat sequence information is analyzed in advance and the azimuth data is received from sensors. The suggested method is evaluated through simulation under the environment like real helicopter.

• Journal of the Korean Society of Propulsion Engineers
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• v.5 no.3
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• pp.87-99
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• 2001

Technical status and prospect of the subsonic airbreathing propulsion system composed of jet engine fuel feeding system and air intake for missile application is described herein, including analysis of some present airbreathing missiles. Comprehension on this can be applicable both to blow deeply about the same type missiles and to get some basic idea of unmanned air vehicle's and light aircraft's propulsion system.

• Strategy21
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• s.41
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• pp.30-51
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• 2017

Neighboring powers in the Korean Peninsula have started to develop and operate aircraft carriers or equivalent forces to cope with rising North Korean nuclear and missile threats and also to show its national might. For example, the United States has added a aircraft carrier from the 3rd fleet to western pacific theater of operation, while Peoples Republic of China is undergoing operational test of Liaoning as well as preparing for christening of its 2nd aircraft carrier. Japan is flexing its muscle as well by deploying Izumo capable of operating F-35B to Southeast Asia to participate in multilateral exercises starting this year. It is a high time to know more about aircraft carriers or similar types in terms of maritime strategy and history. The U.S. has had by far the vast amount of experiences in utilizing aircraft carrier that it would be beneficial for us to examine U.S. perspectives and its application in the Korean Peninsula. It will provide us with insights to understand and predict what it would be like in times of crisis in the Korean Peninsula in the perspective of aircraft carrier's involvement. This paper intends to show some aspects of future conflicts in the Korean Peninsula and how the ROK Navy can best be ready for such situation. For research purpose, U.S. maritime strategy has been developed in stages ; establishment phase, WWI phase, WWII phase, Cold war phase, post Cold war phase. Each phase includes such factors as threats, strategic concept, applications, and ways to improve maritime strategy. Finally, the role of aircraft carrier based on past history as well as future conflict shines the importance to have power projection capabilities for the ROK Navy. The intrinsic nature of the navy in the world is to project power ashore just as history proved it.

• Nuclear Engineering and Technology
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• v.54 no.4
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• pp.1394-1405
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• 2022

The importance of ensuring the inherent safety and security has been more emphasized in recent years to demonstrate the integrity of nuclear facilities under external human-induced events (e.g. aircraft crashes). This work suggests a simulation methodology to effectively evaluate the impact of a commercial aircraft engine onto a dry storage facility. A full-scale engine model was developed and verified by Riera force-time history analysis. A reinforced concrete (RC) structure of a dry storage facility was also developed and material behavior of concrete was incorporated using three constitutive models namely: Continuous Surface Cap, Winfrith, and Karagozian & Case for comparison. Strain-based erosion limits for concrete were suitably defined and the local responses were then compared and analyzed with empirical formulas according to variations in impact velocity. The proposed methodology reasonably predicted such local damage modes of RC structure from the engine missile, and the analysis results agreed well with the calculations of empirical formulas. This research is expected to be helpful in reviewing the dry storage facility design and in the probabilistic risk assessment considering diverse impact scenarios.

• Nuclear Engineering and Technology
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• v.53 no.5
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• pp.1686-1704
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• 2021

This study addresses the numerical simulation of the shield building of an AP1000 nuclear power plant (NPP) subjected to a large commercial aircraft impact. First, a simplified finite element model (F.E. model) of the large commercial Boeing 737 MAX 8 aircraft is established. The F.E. model of the AP1000 shield building is constructed, which is a reasonably simplified reinforced concrete structure. The effectiveness of both F.E. models is verified by the classical Riera method and the impact test of a 1/7.5 scaled GE-J79 engine model. Then, based on the verified F.E. models, the entire impact process of the aircraft on the shield building is simulated by the missile-target interaction method (coupled method) and by the ANSYS/LS-DYNA software, which is at different initial impact velocities and impact heights. Finally, the laws and characteristics of the aircraft impact force, residual velocity, kinetic energy, concrete damage, axial reinforcement stress, and perforated size are analyzed in detail. The results show that all of them increase with the addition to the initial impact velocity. The first four are not very sensitive to the impact height. The engine impact mainly contributes to the peak impact force, and the peak impact force is six times higher than that in the first stage. With increasing initial impact velocity, the maximum aircraft impact force rises linearly. The range of the tension and pressure of the reinforcement axial stress changes with the impact height. The perforated size increases with increasing impact height. The radial perforation area is almost insensitive to the initial impact velocity and impact height. The research of this study can provide help for engineers in designing AP1000 shield buildings.

• 한국전산유체공학회:학술대회논문집
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• 2002.10a
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• pp.88-94
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• 2002

Curved intakes are commonly used from commercial aircraft to military missile. Sound radiation from the intake of air vehicle affects cabin noise, community noise and military detection. In this paper, Sound radiation from curved intake is computed using the high order, high resolution scheme. The generalized characteristic boundary conditions, adaptive nonlinear artificial dissipation model and conformal mapping for high order, high resolution scheme are used. The geometric change of curved intake and the frequency of acoustic source are considered. Two dimensional Euler equations are solved for theses analyses.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.47.5-47
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• 2002

Some integration methods for the linear subsystems are examined and which algorithm is optimal for real-time simulation is considered. First, a number of typical integration methods for a linear time-invariant system are given. Then, the dynamic errors are shown both from the point of view of characteristic root errors and transfer function errors. After that we compute the dynamic errors of integration and choose the appropriate method for each system.