• Journal of the Korean Society of Propulsion Engineers
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• v.11 no.1
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• pp.1-10
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• 2007

Three dimensional structures of detonation waves propagating in a square tube were investigated using a high resolution CFD code coupled with a conservation equation of reaction progress variable and an one-step irreversible reaction. The code were parallelized based on domain decomposition technique using MPI library. The computations were carried on an in-house Windows cluster with AMD processors. Three-dimensional unsteady analysis results in the smoked-foil records caused by the instabilities of the detonation waves, which showed the rectangular and diagonal modes of detonation instabilities depending on the initial condition of disturbances and the spinning detonation for case of small reaction constant.

• Journal of Veterinary Clinics
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• v.16 no.1
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• pp.182-188
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• 1999

This study was performed to determine the causes of the bursting casualties such as death of sows and piglets, abortion, still birth and infertility in a pig farm after consecutive detonation for three months to construct 345 KV in Kimje area. 1. Temperatures in Kimje district, management condition, microorganism in the feed, inbreeding, hematological conditions, and viral agent causing abortion were not proved as the factors of acute occurrence of abortion and infertility in the pig farm. 2. The amount of explosive was increased from 250 kg to 1,100 kg from 23 Dec. 1996 to 28 Jan. 1997 and at the same time the distance between the spot of detonation and the pig farm got closer, from 200 m at the begining to 100 m at the last detonation. 3. Theoretical concussion and sound values were 0.66 kine and 89.39 ㏈, respectively, in the case of 100 m distance between the detonation spot and the pig farm. In conclusion, death of 675 piglets and 11 sows and infertility of 69 sows in the pig farm were assumed to be caused by the concussion or sound stress after detonation.

• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.5
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• pp.121-134
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• 1994

Shock tube investigation of ethylene oxide-$0_{2}-N_{2}$ mixture have been performed to reveal detonation characteristics of the mixture in terms of detonation pressure and speed. Theoretical calculation of thermodynamic parameters at the Chapmann-Jouguet detonation of the mixture has been also performed. A comparision of the observed results with the calculated ones can lead us to predict the detonation parameters of ethylene oxide in an artificial air. In addition, we have observed ignition delay times of ethylene oxide mixtures. The best fit of the observed delay times to Arrhenius gas kinetic relation gives : ${\tau}=10^{-144}{e{xp}}(E_a/RT)[C_{2}H_{4}O]^{-4.8}[O_{2}]^{-12.4}[N_{2}]^{-14.1}$ $E_a=3.67kcal/mole$ The observed activation energy is markedly reduced, compared with the case of ethylene oxide diluted in Ar. It could be due to the factor that $N_2$ play a role as detonation promoter yielding very reactive NOx radicals.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.686-690
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• 2017

In this study, we numerically investigate the detonation characteristics (detonation velocity and pressure) of a hybrid ethylene-air and RDX mixture using two-phase model. Compared with detonation of pure ethylene-air mixture, the detonation of the hybrid ethylene-air and RDX mixture has higher pressure and stronger impulse because the hybrid mixture has additional chemical heat release of RDX particles. To validate the numerical results using two-phase model, we compare the experimental data which show changes of detonation pressure and velocity according to concentration of RDX particles.

• 한국연소학회:학술대회논문집
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• 2005.10a
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• pp.28-31
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• 2005

The numerical simulation is conducted for analysis flame structure of superdetonative ram accelerator experiment by ISL(French-German Research Institute in Saint Louis). Fully coupled chemically non-equilibrium Navier-Stokes equation is used. Shockwave structure of superdetonative ram accelerator and behavior of detonation wave is studied. Maintaining of detonation wave is very important to accelerate projectile, Because detonation wave make high pressure gases and this high pressure accelerate projectile.

• 한국연소학회:학술대회논문집
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• 2012.11a
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• pp.97-99
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• 2012

A pressure-based BOIK model considering Shock to Detonation Transition(SDT) and damage due to external fragment or bullet stimuli impact on energetic materials and analytical approach for determination of free parameters are proposed. The rate of product mass fraction(${\lambda}$) consists of ignition term that represents the initiation due to shock compression and growth term that describes propagation of detonation wave and strain term representing the morphological deformation induced by external impact.

• Journal of Veterinary Clinics
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• v.16 no.2
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• pp.381-388
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• 1999

These investigations were performed to determine the causes of the reproductive disorders of the sows in a pig farm which was located at the distance 36m away from the detonation spot. The reproductive problems of the sows such as abortion and infertility occurred after consecutive detonation and use of heavy equipments to build 6 piers of the bridge for the expressway between Jinju and Taeieon during the period from July 1997 to October 1998. 1. The management condition of the farm, microorganism in the feed, inbreeding, hematological conditions, and viral agent causing abortion were not proved as the factors of the occurrence of abortion and infertility in the pig farm. 2. Theoretical concussion values according to the average amount of explosive per detonation were 1.16 kine for minimum amount (3.6 kg) and 3.45 kine for maximum amount(12.5 kg) of explosive, and the theoretical sound values were accordingly 92.29 decibel for minimum amount and 101.76 decibel for maximum amount of explosive, respectively, in the case of 36m distance between the detonation spot and pig farm. The frequency of detonation in a day was 7 times with interval of 15 minutes. 3. The occurence of infertility in the farm was 57.3% during the period of construction from July 1997 to August 1998. 4. In comparison of body weight of piglets between the damaged and not damaged farms, growth of piglets at the damaged farm was shown to be delayed over 30 days than those of not-damaged farm. In conclusion, abortion of 40 sows, delivery of whole still births of 22 sows, and infertility of 122 sows in the pig farm were assumed to be caused by the concussion or sound stress after consecutive detonation and use of heavy equipments.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.343-346
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• 2005

Three dimensional structures of detonation wave propagating through a square-shaped duct were investigated using computational method and parallel processing. Inviscid fluid dynamics equations coupled with $variable-{\gamma}$ formulation and simplified one-step Arrhenius chemical reaction model were analysed by MUSCL-type TVD scheme and four stage Runge-Kutta time integration. The unsteady computational results in three dimension show the detailed mechanism of transverse mode and diagonal mode of detonation wave instabilities resulting same cell length but different cell width in smoked-foil record.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.431-434
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• 2005

A series of numerical studies are carried out for the different regimes of the detonation phenomena to investigate the computational requirements for the simulation of the cell structure of detonation wave by varying the reaction constants and grid resolutions. The computational results are investigated by comparing the solution of steady ZND structure to draw out the minimum grid resolutions and the size of the computational domain for capturing cell structures of the different regimes of the detonation phenomena.

• 한국전산유체공학회:학술대회논문집
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• 2005.10a
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• pp.151-155
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• 2005

Three-dimensional structures of unsteady detonation wave propagating through a square-shaped tube is studied using computational method and parallel processing. Inviscid fluid dynamics equations coupled with variable-${\gamma}$ formulation and simplified one-step Arrhenius chemical reaction model were analysed by a MUSCL-type TVD scheme and four stage Runge-Kutta time integration. Results in three dimension show the two unsteady detonation wave propagating mode, the Rectangular and diagonal mode of detonation wave instabilities. Two different modes of instability showed the same cell length but different cell width and the geometric similarities in smoked-foil record.