scholarly journals Indoor Test System for Liquid CO2 Phase Change Shock Wave Pressure with PVDF Sensors

Sensors ◽  
2020 ◽  
Vol 20 (8) ◽  
pp. 2395
Author(s):  
Xing Huang ◽  
Qiyue Li ◽  
Xin’ao Wei ◽  
Xiaoxiao Yang ◽  
Dayou Luo ◽  
...  
Keyword(s):  
Shock Wave ◽  
Phase Change ◽  
Polyvinylidene Fluoride ◽  
High Reliability ◽  
Test System ◽  
Axial Distance ◽  
Test Results ◽  
Wave Pressure ◽  
Shock Wave Pressure ◽  
Test Points

Liquid carbon dioxide phase change fracturing technology (LCPCFT) has been widely used in engineering blasting due to the advantage of no flames, and no toxic and harmful gas. However, few studies have been conducted on the acquisition of shock wave pressure and its loading characteristics, which are key parameters in fracturing. Referring to the CO2 in-situ fracturing technology, an indoor test system for shock wave pressure generated during LCPCFT has been built, with a protected polyvinylidene fluoride (PVDF) piezoelectric sensor. Then three verification experiments with different radial distances between the fracturing tube and test points were carried out on the test system, and in each experiment, four PVDF sensors as four test points were arranged with different axial distance from the detonating point to test the pressure distribution. The experimental results show that when the radial distance between the fracturing tube and test points is not too large (≤345 mm), the pressure generated during LCPCFT is approximately uniformly distributed within the axial length of the fracturing tube, but when it is relatively large (≈895 mm), the results between different test points are in a certain degree of dispersion. And finally, this paper uses the intraclass correlation coefficient (ICC) and coefficient of variation (CV) of peak pressure and impulse to process the test results to evaluate the reliability and stability of the test system. Evaluation results show that the test results are in good consistency. The test system in this paper has good stability and high reliability. The test system provides a useful tool for accurately obtaining the shock wave pressure, which is helpful for further research on LCPCFT.

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

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
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.

Influence of a shock-wave pressure gradient on the appearance of a microhardness maximum in α-Fe irradiated by a high-power ion beam

1998 ◽  
Vol 24 (10) ◽  
pp. 819-821 ◽  
Author(s):  
A. N. Valyaev ◽  
A. D. Pogrebnyak ◽  
S. N. Bratushka ◽  
V. I. Lavrent’ev ◽  
S. N. Volkov ◽  
...  
Keyword(s):  
Shock Wave ◽  
Pressure Gradient ◽  
High Power ◽  
Ion Beam ◽  
Wave Pressure ◽  
Shock Wave Pressure

Effects of the aluminum content on the shock wave pressure and the acceleration ability of RDX-based aluminized explosives

2014 ◽  
Vol 116 (14) ◽  
pp. 144906 ◽  
Author(s):  
Z. Q. Zhou ◽  
J. X. Nie ◽  
Z. C. Ou ◽  
J. F. Qin ◽  
Q. J. Jiao
Keyword(s):  
Shock Wave ◽  
Aluminum Content ◽  
Wave Pressure ◽  
Acceleration Ability ◽  
Shock Wave Pressure

scholarly journals Superconductivity of Mg/MgO interface formed by shock-wave pressure

2013 ◽  
Vol 488 ◽  
pp. 18-24 ◽  
Author(s):  
N.S. Sidorov ◽  
A.V. Palnichenko ◽  
D.V. Shakhrai ◽  
V.V. Avdonin ◽  
O.M. Vyaselev ◽  
...  
Keyword(s):  
Shock Wave ◽  
Wave Pressure ◽  
Shock Wave Pressure

Measuring Projectile Velocity using Shock Wave Pressure Sensors

2014 ◽  
Vol 64 (6) ◽  
pp. 499-501 ◽  
Author(s):  
Sankarsan Padhy ◽  
◽  
Susmita Panigrahi
Keyword(s):  
Shock Wave ◽  
Pressure Sensors ◽  
Projectile Velocity ◽  
Wave Pressure ◽  
Shock Wave Pressure
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