scholarly journals Investigating Different Grounds Effects on Shock Wave Propagation Resulting from Near-Ground Explosion

2019 ◽  
Vol 9 (17) ◽  
pp. 3639 ◽  
Author(s):  
Yan Wang ◽  
Hua Wang ◽  
Cunyan Cui ◽  
Beilei Zhao
Keyword(s):  
Shock Wave ◽  
Enhancement Effect ◽  
Liquid Propellant ◽  
Time Curve ◽  
Pressure Time ◽  
Launch Site ◽  
Propagation Law ◽  
Ground Shock ◽  
The Impact ◽  
Propellant Rocket

A massive explosion of a liquid-propellant rocket in the course of an accident can lead to a truly catastrophic event, which would threaten the safety of personnel and facilities around the launch site. In order to study the propagation of near-ground shock wave and quantify the enhancement effect on the overpressure, models with different grounds have been established based on an explicit nonlinear dynamic ANSYS/LS-DYNA 970 program. Results show that the existence of the ground will change the propagation law and conform to the reflection law of the shock wave. Rigid ground absorbs no energy and reflects all of it, while concrete ground absorbs and reflects some of the energy, respectively. Ground may influence the pressure-time curve of the shock wave. When the gauge is close to the explosive, the pressure-time curve presents a bimodal feature, while when the gauge reaches a certain distance to the explosive, it presents a single-peak feature. For gauges at different heights, different grounds may have different effects on the peak overpressure. For gauges of height not greater than 4 m, the impact on the shock wave is obvious when the radial to the explosive is small. On the contrary, as for the gauges of height greater than 4 m, the impact on the shock wave is obvious when the radial to the explosive is big. Ground has the enhancement effect on peak overpressure, but different grounds have different ways. For rigid ground, the peak overpressure factor is about 2. However, for the concrete and soil ground, peak overpressure factor is from 1.43 to 2.1.

Experimental Analysis of the Influence of Length to Diameter Ratio on Erosive Burning in a Solid Tubular Propellant Grain

2011 ◽  
Vol 110-116 ◽  
pp. 3394-3399 ◽  
Author(s):  
Mohammad Reza Zadeh Sheikholeslam ◽  
Daryoosh Kazemi ◽  
Hooman Amiri
Keyword(s):  
Diameter Ratio ◽  
Dynamical Analysis ◽  
Solid Propellants ◽  
Mean Velocity ◽  
Time Curve ◽  
Rocket Motors ◽  
Erosive Burning ◽  
Pressure Time ◽  
Solid Propellant Rocket ◽  
Propellant Rocket

Erosive burning usually refers to the increase in the propellant burning rate caused by high velocity combustion gasses flowing over the propellant surface. It may seriously affect the performance of solid-propellant rocket motors [1]. A series of experiments had been made to study the effects of length to the diameter ratio in a single tubular propellant grain on the erosive burning phenomenon. In the same combustion pressure and different grain geometries, the burning pattern ofAP1based propellantwere recorded. Furthermore, pressure-time curve for each condition was obtained. The mean velocity gradient is obtained by some thermo-gas-dynamical analysis on experimental data. The results can be used for preliminary design ofAPbased tubular propellant rocket motors. This method may be used for other types of tubular solid propellants which defer in chemical formulation.

scholarly journals Influence of air shock wave on shelter

2020 ◽  
pp. 133-144
Author(s):  
Volodymyr Kotsiuruba ◽  
Ivan Datsenko ◽  
Volodymyr Dachkovsky ◽  
Ruslan Cherevko ◽  
Vasyl Polyulyak ◽  
...  
Keyword(s):  
Shock Wave ◽  
Stokes Equations ◽  
Experimental Studies ◽  
Navier Stokes ◽  
Maximum Pressure ◽  
Navier Stokes Equations ◽  
Pressure Time ◽  
Protective Structures ◽  
Short Time ◽  
The Impact

In modern conditions, sheltering people in protective structures, as a way of protection from dangers, in combination with evacuation from the affected areas (pollution) and the use of personal protective equipment, increases the reliability of public protection. In conditions when evacuation measures from cities can be complicated in a short time, protection of the population in shelters becomes the only possible and effective. Therefore, an important task is to study the impact of loads caused by the explosion of various munitions, substantiate recommendations for improving the protective properties of the shelter and the choice of their location. The most common issues are considered in the article that arise during the arrangement of shelter in buildings and outside them. Based on experimental studies, Taylor's formula and the system of non-stationary Navier-Stokes equations for gas, it’s conducted an analysis of the influence of external and internal factors on the possible nature of the dynamic load from the shock wave on buildings, structures and structural elements in which shelters are located. The results of studies of the parameters of dynamic loads showed that if the storage facilities are located in the basements of buildings, their stability is characterized by three parameters: maximum pressure, time to increase the load to maximum and effective time. The parameters of the loads and the law of their change over the time depend on the location of the structure relative to the surface of the earth and the building, the force of the explosion and the distance to the center of the explosion.

Studies on Scabbing of Solids Under Explosive Attack

1955 ◽  
Vol 22 (3) ◽  
pp. 317-323
Author(s):  
K. B. Broberg
Keyword(s):  
Shock Wave ◽  
Free Surface ◽  
High Pressures ◽  
Normal Incidence ◽  
Plane Shock ◽  
Detonation Pressure ◽  
Time Curve ◽  
Pressure Time ◽  
Administrative Service ◽  
Very High

Abstract The purpose of this paper is to analyze the mechanism of the scabbing phenomenon that occurs when an intense shock wave in a solid is reflected against a free surface. Only plane shock waves with normal incidence to the free surface are discussed. The shock wave is assumed to be initiated by the detonation of an explosive (especially TNT with a loading density of 1.5 g/cm3). The calculations are based upon values given by H. Jones and A. R. Miller (for the detonation pressure), D. J. McAdam (for the strength of the material at combined stresses), P. W. Bridgman (for the quantitative behavior of the material at very high pressures) and, finally, upon results from the author’s own experiments regarding the impulse and the pressure-time curve at detonation in contact with a metal surface. It is shown that fracture sometimes is likely to occur in several parallel layers of the material. Experiments have been performed which support the theoretical analysis. The research was carried out at the Royal Swedish Fortification and Works Administrative Service, Stockholm.

Liquid propellant rocket engines - Their status and future.

1967 ◽  
Vol 4 (12) ◽  
pp. 1569-1580 ◽  
Author(s):  
R. V. BURRY ◽  
S. F. IACOBELLIS ◽  
V. R. LARSON
Keyword(s):  
Rocket Engines ◽  
Liquid Propellant ◽  
Propellant Rocket

scholarly journals Computational Evaluation of Shock Wave Interaction with a Cylindrical Water Column

2021 ◽  
Vol 11 (11) ◽  
pp. 4934
Author(s):  
Viola Rossano ◽  
Giuliano De Stefano
Keyword(s):  
Shock Wave ◽  
Water Column ◽  
Wave Interaction ◽  
Navier Stokes ◽  
Plane Shock ◽  
Governing Equations ◽  
Computational Evaluation ◽  
Air Water Interface ◽  
The Mean ◽  
The Impact

Computational fluid dynamics was employed to predict the early stages of the aerodynamic breakup of a cylindrical water column, due to the impact of a traveling plane shock wave. The unsteady Reynolds-averaged Navier–Stokes approach was used to simulate the mean turbulent flow in a virtual shock tube device. The compressible flow governing equations were solved by means of a finite volume-based numerical method, where the volume of fluid technique was employed to track the air–water interface on the fixed numerical mesh. The present computational modeling approach for industrial gas dynamics applications was verified by making a comparison with reference experimental and numerical results for the same flow configuration. The engineering analysis of the shock–column interaction was performed in the shear-stripping regime, where an acceptably accurate prediction of the interface deformation was achieved. Both column flattening and sheet shearing at the column equator were correctly reproduced, along with the water body drift.

Analysis of the Samples of Fe-Cu-Nb-Si-B Amorphous Alloys Obtained by Dynamic Compacting Method

2005 ◽  
Vol 903 ◽  
Author(s):  
Victor A. Golubev ◽  
Andrey V. Strikanov ◽  
Grigory A. Potemkin ◽  
Ludmila V. Zueva ◽  
Aleksey V. Golubev ◽  
...  
Keyword(s):  
Shock Wave ◽  
Amorphous Alloys ◽  
Analysis Data ◽  
Xrd Analysis ◽  
Soft Magnetic ◽  
Scanning Calorimetry ◽  
Soft Magnetic Alloys ◽  
Nano Crystalline ◽  
The Impact ◽  
Magnetic Conductivity

AbstractThe Dynamic Compacting (DC) method is promising method to produce considerable-size nonporous wares. The phenomenon is based on the impact of shock wave on the initial powders of amorphous alloys. Every time when the shock wave propagates through the bulk of substance then the temperature rises substantially. Therefore there is a need of study of the DC’s effect on the structure and properties of the amorphous alloys. The results of the thermal analysis (in particular, Differential Scanning Calorimetry) of the samples of the soft magnetic alloys are presented in the report. These results concern with amorphous alloys of 5BDSR, GM414, 10NSR trademarks before DC and after DC, respectively. It is shown there is single low-temperature endothermic peak (near 300C) and there are several high temperature exothermic peaks (near 540C, 650C, and 700C). The first peak is related to glass-transition, the following peaks are related to formation of nano-crystalline phases. It was proved by XRD analysis data. The optimal regimes of the thermal processing of final wares were chosen on the base of thermal- and XRD-analysis. The study of the effects of these regimes on the properties (magnetic conductivity, specific losses etc.) of the circular magnetic conductors was executed. In particular, thermal- as well as thermo-magnetic processing of magnetic conductors based on 5BDSR amorphous alloy (after DC) essentially improves their magnetic properties. For example, magnetic conductivity fÝ increases approximately by factor 17 with respect to the magnitude before DC.

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