• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.217-225
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• 2010

A Through-Bulkhead Initiation Module(TBIM) works as the shock-wave generated by the detonation of donor explosive transmits to acceptor explosive. In order to estimate the minimum thickness of the bulkhead of TBIM, the structural stress of TBIM housing is calculated via modeling analysis, and which shows a sufficient margin in strength as the minimum thickness is bigger than 0.1 mm. The free surface velocity at the metal to explosive interface is measured using VISAR to determine the optimal thickness of bulkhead. The shock pressure is calculated from the measured free surface velocity, and the probability of TBIM with respect to the thickness of bulkhead is estimated by comparing the sensitivity of acceptor explosive with it.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.4
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• pp.16-24
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• 2010

A Through-Bulkhead Initiation Module(TBIM) works as the shock-wave generated by the detonation of donor explosive transmits to acceptor explosive. In order to estimate the minimum thickness of the bulkhead of TBIM, the structural stress of TBIM housing is calculated via modeling analysis, and which shows a sufficient margin in strength as the minimum thickness is bigger than 0.1 mm. The free surface velocity at the metal to explosive interface is measured using VISAR to determine the optimal thickness of bulkhead. The shock pressure is calculated from the measured free surface velocity, and the probability of TBIM with respect to the thickness of bulkhead is estimated by comparing the sensitivity of acceptor explosive with it.

• Journal of the Korean Society of Propulsion Engineers
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• v.21 no.4
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• pp.36-43
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• 2017

We studied attenuation characteristics of shock waves induced by a donor charge and the sensitivity of an acceptor for optimal design of a TBI (Through-bulkhead initiator). The attenuation behavior of shock waves was studied by measuring free surface velocity using a VISAR (Velocity Interferometer System for Any Reflector), and the sensitivity of the acceptor explosives was analyzed via SSGT (Small Scale Gap Test). It was found that the acceptor sensitivity obtained by the SSGT may be inappropriate for the design of the small-scale explosive devices such as TBI due to the different shock duration time.

• Journal of Mechanical Science and Technology
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• v.15 no.12
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• pp.1822-1828
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• 2001

The experiment for the sympathetic detonation (Sudo et al., 1951) (Fukuyama et al., 1958) in water was conducted. Composition B (RDX: 64%, TNT: 36%, Detonation velocity: 7900m/s) was used for both donor (the thickness was 50mm, and the diameter was 31mm) and receptor charges. The distance between the donor and the receptor, and the thickness (5, 7.5, 10mm) of the receptor were varied in the experiments. In order to investigate the basic characteristics of the underwater sympathetic detonation of high explosive, the sympathetic detonation phenomena were visualized by a high-speed camera (HADLAND PHOTONICS, IMACON790) in forms of streak and framing photographs. The 200ns/mm streak velocity was 2㎲. Manganin gauges (KYOWA Electronic INSTRUMENTS CO. SKF-21725) were used for the pressure measurements. The gauges were set under the receptor. The pressures during the complete and incomplete explosions were measured.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.2
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• pp.75-85
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• 2016

A pyrotechnic system consisting of donor/acceptor pair separated by a gap relies on shock attenuation characteristics of the gap material and shock sensitivity of the donor and acceptor charges. Despite of its common use, numerical study of such pyrotechnic train configuration is seldom reported because proper modeling of the full process requires precise capturing of the shock wave attenuation in the gap prior to triggering a full detonation of high explosive and accurate description of the high strain rate dynamics of the explosively loaded inert confinements. We apply a Eulerian level-set based multimaterial hydrocode with reactive flow models for pentolite donor and heavily aluminized RDX as acceptor charge. The complex shock interaction, critical gap thickness, acoustic impedance, and go/no-go characteristics of the gap test are quantitatively investigated.

• Journal of the Korean Society of Propulsion Engineers
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• v.21 no.5
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• pp.80-87
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• 2017

The performance of a pyrotechnic device that consists of donor/acceptor pair separated by a bulkhead relies on shock attenuation characteristics of the gap material and shock sensitivity of the donor and acceptor explosives. In this research, a micro Kapton flyer was accelerated by an exploding foil initiator (EFI) to figure out shock sensitivity of hexanitrostilbene (HNS) to impact. The averaged shock pressure and duration imparted to the explosive by flyer impact are measured by using a velocity interferometer for any reflector (VISAR) and impedance matching technique. Consequently, this research shows the possibility to determine the critical flyer velocity for initiating the miniaturized pyrotechnic unit by determining the relations between the impact velocity, the amplitude and width of impact loading.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.5
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• pp.1-11
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• 2014

Sympathetic detonation (SD) of high explosives occurs when a detonating donor initiates neighboring acceptors. The present study focuses on the hydrodynamic simulation of one-on-one sympathetic detonation of 155 mm charge filled with PBXN-109. Both unbuffered and buffered SD configurations are performed while changing the distance between each charge, in order to investigate the detonation sensitivity to a donor initiation. The cause of a SD is by a shock impact for the unbuffered case at a close range, while at a distant range, blast fragment penetration is the primary cause. The buffers can reduce the incident sensitivity to a SD by reducing the strengths of shock wave and impinging fragments.

• Journal of the Korea Society for Simulation
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• v.28 no.2
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• pp.1-14
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• 2019

A full scale hydrodynamic simulation that requires an accurate reproduction of shock-induced detonation was conducted for design of an energetic component system. A detailed hydrodynamic analysis SW was developed to validate the reactive flow model for predicting the shock propagation in a train configuration and to quantify the shock sensitivity of the energetic materials. The pyrotechnic device is composed of four main components, namely a donor unit (HNS+HMX), a bulkhead (STS), an acceptor explosive (RDX), and a propellant (BPN) for gas generation. The pressurized gases generated from the burning propellant were purged into a 10 cc release chamber for study of the inherent oscillatory flow induced by the interferences between shock and rarefaction waves. The pressure fluctuations measured from experiment and calculation were investigated to further validate the peculiar peak at specific characteristic frequency (${\omega}_c=8.3kHz$). In this paper, a step-by-step numerical description of detonation of high explosive components, deflagration of propellant component, and deformation of metal component is given in order to facilitate the proper implementation of the outlined formulation into a shock physics code for a full scale hydrodynamic simulation of the energetic component system.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.4 no.2
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• pp.153-159
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• 2006

It is a serious task to the decommissioning of the uranium conversion plant that the demolition of the lagoon sludge. The main component of the sludge is ammonium nitrate and that is the very explosive material. Therefore, the bio-denitrification is a attractive process to remove the nitrate. In this work, some process variables was tested such as incubation temperature, nitrate concentration, electron donor, C/N ratio, seeding ratio, and pH with an anaerobic bacteria as Pseudomonas halodenitrificans. The results would be used as basic data to the continuous bio-denitrification process.