Numerical Study on Propagation of Ice Breaking Shock Waves in Process of Breaking Ice by Double-Layer Charge Blasting

The ice-breaking process of the double-layer charge at a depth of 150 cm underwater is simulated by LS-DYNA. This paper analyzes the load type, shock wave pressure characteristics and propagation behavior of the double-layer charge during underwater explosion. By analyzing the impact of the shock wave pressure in the water under different charge intervals and time intervals on the shock wave pressure of the double charge, it is concluded that the peak pressure of the double charge explosion shock wave is jointly determined by the double charge. In this range, the second peak pressure value of the drug is greater than the pressure value of the first peak of the drug, and the attenuation is slow; the delay time of the upper charge has little effect on the peak pressure value of the shock wave in the water; the delay time is higher than that of the lower charge Initiation, at the same position, the total pressure peak of the shock wave formed by the delay of the upper charge is larger.

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Study on the Shock Wave Pressure Characteristics of Pulsed Discharge in Liquid in the Pipe

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.805-806.906 ◽

2013 ◽

Vol 805-806 ◽

pp. 906-910 ◽

Cited By ~ 1

Author(s):

Zhi Ying Gao ◽

Bing Sun ◽

Bo Wang ◽

Xiao Mei Zhu ◽

Zhi Yu Yan

Keyword(s):

Shock Wave ◽

Shock Waves ◽

Peak Pressure ◽

Discharge Voltage ◽

Wave Intensity ◽

Pulsed Discharge ◽

Electrode Gap ◽

Wave Pressure ◽

Wave Characteristics ◽

Shock Wave Pressure

In this paper, the shock wave characteristics of pulsed discharge in liquid which occurred in the pipe with rod-rod electrodes were studied. The effects of shock wave peak pressure in the discharge were studied with changed the discharge voltage and electrode gap. The results show that the peak pressure of shock wave increased with the increasing of voltage. When the discharge voltage 22kV, the peak pressure of shock wave increased first and then decreased with the electrode gap increased. However, the discharge voltages 26kV and 28kV, the peak pressure of shock waves increased with electrode gap increased. The pressure of the shock wave (Pr) decays exponentially with the distance (r) from the discharging center. Under this experimental condition, the shock wave intensity is calculated by averaging many values of the experiment, and the experience formula is Pr = 2.56E·e-0.4831r.

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A Lab-Scale Experiment Approach to the Measurement of Wall Pressure from Near-Field under Water Explosions by a Hopkinson Bar

Shock and Vibration ◽

10.1155/2018/8273469 ◽

2018 ◽

Vol 2018 ◽

pp. 1-15 ◽

Cited By ~ 4

Author(s):

Xiongwei Cui ◽

Xiongliang Yao ◽

Yingyu Chen

Keyword(s):

Shock Wave ◽

Near Field ◽

Underwater Explosion ◽

Experimental System ◽

Hopkinson Bar ◽

Wall Pressure ◽

Pressure Loading ◽

Target Plate ◽

Wave Pressure ◽

Shock Wave Pressure

Direct measurement of the wall pressure loading subjected to the near-field underwater explosion is of great difficulty. In this article, an improved methodology and a lab-scale experimental system are proposed and manufactured to assess the wall pressure loading. In the methodology, a Hopkinson bar (HPB), used as the sensing element, is inserted through the hole drilled on the target plate and the bar’s end face lies flush with the loaded face of the target plate to detect and record the pressure loading. Furthermore, two improvements have been made on this methodology to measure the wall pressure loading from a near-field underwater explosion. The first one is some waterproof units added to make it suitable for the underwater environment. The second one is a hard rubber cylinder placed at the distal end, and a pair of ropes taped on the HPB is used to pull the HPB against the cylinder hard to ensure the HPB’s end face flushes with loaded face of the target plate during the bubble collapse. To validate the pressure measurement technique based on the HPB, an underwater explosion between two parallelly mounted circular target plates is used as the validating system. Based on the assumption that the shock wave pressure profiles at the two points on the two plates which are symmetrical to each other about the middle plane of symmetry are the same, it was found that the pressure obtained by the HPB was in excellent agreement with pressure transducer measurements, thus validating the proposed technique. To verify the capability of this improved methodology and experimental system, a series of minicharge underwater explosion experiments are conducted. From the recorded pressure-time profiles coupled with the underwater explosion evolution images captured by the HSV camera, the shock wave pressure loading and bubble-jet pressure loadings are captured in detail at 5 mm, 10 mm, …, 30 mm stand-off distances. Part of the pressure loading of the experiment at 35 mm stand-off distance is recorded, which is still of great help and significance for engineers. Especially, the peak pressure of the shock wave is captured.

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