scholarly journals Computational simulation of shock wave generated by the detonation of explosives for civil use

2020 ◽  
Vol 305 ◽  
pp. 00019
Author(s):  
Ligia Ioana Tuhuţ ◽  
Emilian Ghicioi
Keyword(s):  
Shock Wave ◽  
A Priori ◽  
Computational Simulation ◽  
Free Field ◽  
Concrete Surface ◽  
Prevention Measures ◽  
Explosion Pressure ◽  
Computerized Simulation ◽  
Freely Suspended ◽  
Real Scenario

When conducting a research concerning the propagation of a shock wave generated by the detonation of civil use explosives, the first thing that comes to mind should be if the detonation process takes place in an obstacle-free field, or the area has obstacles such as rocks, metals structures, wood etc, obstacles that can and will influence the final results, the shock wave curve being obturated by it. On one hand, the paper presents the experimental results obtained after the detonation of a freely suspended load, placed at 0.5m above a concrete surface. On the other hand, it compares the values of explosion pressure as shock wave, measured on 4 sensors linearly disposed at the same elevation to the ground, at a distance of 2,3,4 respectively 6 meters from the explosive charge. These values are determined through computerized simulation, using ANSYS AUTODYN software, by virtually reproducing the real scenario. Following the two experiments (real and virtual), one can conclude that computerized simulation proves to be a very useful instrument in an a priori evaluation of hazardous situations/utility of peak values for shock wave, by allowing the user to develop prevention measures/optimization of the analysed processes and also in further investigations

Research on Corner Structure Under Explosive Loading for War-Ship Cabin

2010 ◽  
Author(s):  
Xiangshao Kong ◽  
Shuangxi Xu ◽  
Weiguo Wu ◽  
Xiaobin Li ◽  
Yuanzhou Zheng
Keyword(s):  
Shock Wave ◽  
Nonlinear Dynamic ◽  
Failure Process ◽  
High Strength ◽  
Explosive Loading ◽  
Inclined Plate ◽  
Explosion Pressure ◽  
Conventional Structure ◽  
Dynamic Software ◽  
Plate Connection

For the warship cabin under explosive loading, the detail structure in cabin corner can easily be torn by the high-strength shock wave converging at the structure corner. In order to avoid that the crevasse occurs at the corner firstly, three strengthening structure forms were designed for the cabin corner: thickening connection, circular connection and inclined plate connection. Failure process of the joint in the two-cabin structure under the explosive loading was simulated by the nonlinear dynamic software DYTRAN. Comparing the response of the corner strengthening structure to that of the conventional structure, it was concluded that three strengthening structure forms changed failure mode of the cabin structure effectively and the crevasse initiated at the explosion pressure release hole on the transverse bulkhead, which reduced the tearing of the cabin corner. To seek more reasonable corner strengthening structure, the pressure and the stress on the bulkhead under the explosive loading of the three corner strengthening structures were compared. The results showed the inclined plate connection can prevent the shock wave from concentrating at the corner, decrease the stress on the longitudinal bulkhead, and resist the shock wave spreading into the inner cabins most effectively in the three strengthening forms.

Simulation and Validation of Centrifugal Impeller Shock Wave and Acoustic Power Prediction

2012 ◽  
Author(s):  
Robert H. Schlinker ◽  
Arthur Blanc ◽  
Elizabeth Lurie ◽  
Jongwook Joo ◽  
Aaron Reimann ◽  
...  
Keyword(s):  
Shock Wave ◽  
Shock Waves ◽  
Free Field ◽  
Acoustic Power ◽  
Centrifugal Impeller ◽  
Power Prediction ◽  
Impeller Blade ◽  
Simulation Based ◽  
Compressor Inlet ◽  
Development And Validation

In this paper, we describe the development and validation of a simulation based methodology for predicting centrifugal impeller rotor locked noise generated at supersonic relative tip speeds when shock waves dominate the acoustic field. Propagating shock waves were calculated in the compressor inlet with a RANS code using an acoustic quality grid to track the sound power as the shocks transition from non-linear to linear propagating wavefronts. The predicted shocks were compared with unsteady pressure measurements obtained from sensors installed on the impeller shroud wall as part of the validation procedure. Calculated shock signatures compared well with the directly measured pressure field propagating over the shroud wall. An independent measurement of acoustic power was also conducted in the free field outside of the test cell. The predicted acoustic power compared within 1dB of the direct measurement validating the simulation based methodology for centrifugal impeller rotor locked shock noise. The resulting study provides both prediction and measurement of the generation, evolution, and far field acoustic power of centrifugal impeller blade passage shock wave noise.

scholarly journals Experimental Study on Explosion Pressure and Rock Breaking Characteristics under Liquid Carbon Dioxide Blasting

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Yanan Zhang ◽  
Junren Deng ◽  
Bo Ke ◽  
Hongwei Deng ◽  
Jielin Li
Keyword(s):  
Carbon Dioxide ◽  
High Pressure ◽  
Free Field ◽  
Jet Impingement ◽  
Rock Breaking ◽  
Tensile Failure ◽  
Liquid Carbon ◽  
Liquid Carbon Dioxide ◽  
Explosion Pressure ◽  
The Impact

A liquid carbon dioxide blasting experiment was carried out under free field conditions, alongside a liquid carbon dioxide rock breaking experiment, to investigate explosion pressure variation and rock breaking characteristics under liquid carbon dioxide blasting. The experimental results show that the internal and external explosion pressures of the liquid carbon dioxide fracturing devices all rapidly increased at first, before attenuating vibrantly after blasting. When the explosion pressure was raised, the internal explosion pressure increased first exponentially and then linearly, while the external explosion pressure increased exponentially throughout. The duration time of the blasting effect stage was about 45 ms. Under the combined effect of jet impingement and a gas wedge of high-pressure carbon dioxide, the rock is subjected to tensile failure. The impact failure and the “gas wedge effect” of high-pressure carbon dioxide play a key role in the rock breaking of liquid carbon dioxide blasting technology.

scholarly journals Modeling of the whole process of shock wave overpressure of free-field air explosion

2019 ◽  
Vol 15 (5) ◽  
pp. 815-820
Author(s):  
Zai-qing Xue ◽  
Shunping Li ◽  
Chun-liang Xin ◽  
Li-ping Shi ◽  
Hong-bin Wu
Keyword(s):  
Shock Wave ◽  
Free Field ◽  
Whole Process ◽  
Air Explosion

Computational simulation of laser plasma emission with shock-wave-affected density distribution in the gas-jet target

2016 ◽  
Vol 42 (10) ◽  
pp. 993-996 ◽  
Author(s):  
A. V. Garbaruk ◽  
M. S. Gritskevich ◽  
S. G. Kalmykov ◽  
M. E. Sasin
Keyword(s):  
Shock Wave ◽  
Density Distribution ◽  
Laser Plasma ◽  
Computational Simulation ◽  
Gas Jet ◽  
Plasma Emission

scholarly journals Effects of Explosion Shock Waves on Lung Injuries in Rabbits

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Yanlong Sun ◽  
Xinming Qian ◽  
Chi-Min Shu ◽  
Ziyuan Li ◽  
Mengqi Yuan ◽  
...  
Keyword(s):  
Shock Wave ◽  
Shock Waves ◽  
Free Field ◽  
Damage Mechanism ◽  
Injury Mechanism ◽  
Severe Injury ◽  
Severe Injuries ◽  
Lung Injuries ◽  
Test Points ◽  
Hematoxylin Eosin

The purpose of this study was to explore the damage effects and injury mechanism of free-field explosion shock waves on rabbit lungs. Six free-field explosion experiments, each with 500 g trinitrotoluene (TNT), were conducted as the shock wave overpressure acting on the rabbits was measured. The peak overpressure of the shock wave was 533, 390, 249, 102, and 69 kPa at the respective test points. Damage to the rabbit lungs caused by shock wave overpressure was investigated through observation, anatomical analysis, and hematoxylin-eosin (HE) staining processing. The shock wave overpressure of 69–102 kPa caused mild-to-moderate injury; the shock wave overpressure of 102–249 kPa caused moderate injury; the shock wave overpressure of 249–390 kPa resulted in moderate-to-severe injury; and the shock wave overpressure of 390–533 kPa caused severe injury to the rabbit. Mild, moderate, and severe injuries destroyed some, most, or all alveolar structures, correspondingly, as well as producing partial cell apoptosis. The overpressure damage mechanism primarily involves the collapse and rupture of pulmonary alveolus in the lung tissue. As a novel attempt, the investigation provided here may serve to improve the current shock wave injury mechanism.

scholarly journals The shock wave compaction of ceramic powders

2019 ◽  
Vol 23 (Suppl. 2) ◽  
pp. 471-476 ◽  
Author(s):  
Andrey Buzyurkin ◽  
Evgeny Kraus ◽  
Yaroslav Lukyanov
Keyword(s):  
Shock Wave ◽  
Aluminum Oxide ◽  
Boron Carbide ◽  
Experimental Investigations ◽  
Ceramic Powders ◽  
Special Equipment ◽  
Explosive Compaction ◽  
Compact Sample ◽  
Explosion Pressure ◽  
Mathematical And Physical Modeling

Joint theoretical and experimental investigations have allowed to realize an approach with use of mathematical and physical modeling of processes of a shock wave compaction of ceramic powders. The aim of this study was to obtain a durable low-porosity compact sample. The explosive compaction technology is used in this problem because ceramic powders such as boron carbide and aluminum oxide is an extremely hard and refractory material. Therefore, its compaction by traditional methods requires special equipment and considerable expenses. In order to better understand the influence of the loading conditions and, in particular, to study the effect of detonation velocity, explosive thickness and explosion pressure on the properties of the final sample, the problem of compaction of the powder in an axisymmetric case using the conditions of the above experiments have been numerically solved. Thus, using the technology of explosive compaction, compact samples of boron carbide and aluminum oxide are obtained. On the basis of experimental and numerical studies of shock waves propagation, the optimum scheme and parameters of dynamic compaction of boron carbide and aluminum oxide are determined in order to maximize the density and the conservation of the samples after dynamic loading.

Numerical Analysis of Shock Wave Propagation Law of Internal Gas Explosion

2011 ◽  
Vol 105-107 ◽  
pp. 299-302
Author(s):  
Xiu Hua Zhang ◽  
Yan Yan Wu
Keyword(s):  
Shock Wave ◽  
Wave Propagation ◽  
Initial Energy ◽  
Shock Wave Propagation ◽  
Coupling Method ◽  
Frame Structure ◽  
Gas Explosion ◽  
Fluid Structure ◽  
Explosion Pressure ◽  
Propagation Law

The purpose of this paper is to research on shock wave propagation law of internal gas explosion. The multi-material Eulerian and Lagrangian coupling algorithm was adopt. Using ANSYS/LS-DYNA dynamic analysis software to build frame structure, air and gas explosion models. Multiple ALE elements for simulating air and gas explosion material the analysis of blast shock wave propagation in a three-story steel frame structure and the characteristics of explosion pressure using fluid-structure coupling method are carried out. The conclusions show that fluid-structure coupling method can well simulated shock wave propagation of internal gas explosion, and the pressure peak of blast shock wave increased with the increasing of the blast air initial energy. Locality is the characteristic of explosion pressure in sealed space, and the pressure pass weakly when it propagates in solid.

Computational Simulation on Performance Enhancement of Cold Gas Dynamic Spray Processes With Electrostatic Assist

2008 ◽  
Vol 130 (8) ◽  
Author(s):  
Hidemasa Takana ◽  
Kazuhiro Ogawa ◽  
Tetsuo Shoji ◽  
Hideya Nishiyama
Keyword(s):  
Shock Wave ◽  
Electrostatic Force ◽  
Computational Simulation ◽  
Viscous Drag ◽  
Formation Model ◽  
Spray Process ◽  
Gas Dynamic ◽  
Cold Gas Dynamic Spray ◽  
Gas Dynamic Spray ◽  
Cold Gas

A real-time computational simulation on the entire cold spray process is carried out by the integrated model of compressible flow field, splat formation model, and coating formation model, in order to provide the fundamental data for the advanced high performance cold gas dynamic spray process with electrostatic acceleration. In this computation, viscous drag force, flow acceleration added mass, gravity, Basset history force, Saffman lift force, Brownian motion, thermophoresis, and electrostatic force are all considered in the particle equation of motion for the more realistic prediction of in-flight nano∕microparticle characteristics with electrostatic force and also for the detailed analysis of particle-shock-wave-substrate interaction. Computational results show that electrostatic acceleration can broaden the smallest size of applicable particle diameter for successful adhesion; as a result, wider coating can be realized. The utilization of electrostatic acceleration enhances the performance of cold dynamic spray process even under the presence of unavoidable shock wave.

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