scholarly journals The Penetration–Explosion Effects of Differently Distributed Inactive/Active Composite Shaped Charge Jets

Materials ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 344
Author(s):  
Jiacheng Peng ◽  
Jianwei Jiang ◽  
Jianbing Men ◽  
Jinlin Li ◽  
Dongkang Zhou ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Double Layer ◽  
High Speed ◽  
Shaped Charge ◽  
The Other ◽  
High Speed Photography ◽  
Active Composite ◽  
Deformation Area ◽  
Full Height

An analysis of the penetration–explosion (PE) effects of four distributions of inactive/active composite jets shows that a well-designed inactive/active double-layer liner can promote composite jet damage. Penetration experiments were then carried out for shaped charge jets having a single inactive (Cu) liner or an inactive/active (Cu/Al) double-layer liner with variable liner height. The behaviors and firelight patterns of the different jets were captured by high-speed photography. The perforation, deformation area, and deflection were measured for each plate, showing that the Cu/Al jets have stronger PE effects. Numerical simulation shows that the tip of the composite jet generated from the full-height liner is only Cu, whereas for the other jet, from the double-layer liner, Cu is almost wrapped entirely by Al.

Evaluation of the Scott bond test method

2012 ◽  
Vol 27 (2) ◽  
pp. 231-236 ◽  
Author(s):  
Christer Fellers ◽  
Sören Östlund ◽  
Petri Mäkelä
Keyword(s):  
Tensile Test ◽  
Total Energy ◽  
High Speed ◽  
Test Methods ◽  
Test Method ◽  
The Other ◽  
High Speed Photography ◽  
Tensile Tester ◽  
Delamination Resistance ◽  
Energy Consuming

Abstract The Scott bond test is the most commonly used test method for quantifying the delamination resistance of paper and board. The objective of this investigation was to validate the hypothesis that the Scott bond value would be dominated by the total energy under the force elongation curve in a z-directional tensile test. The investigation comprised three types of hand sheets with comparatively low strength values. Three test methods were used to obtain the energy for delamination: 1) Z-test, a z-directional tensile test, 2) Scott bond test, and 3) Simulated Scott bond test, a Scott bond type of test performed in a hydraulic tensile tester. The test data were expressed as a correlation between the failure energy obtained from the Z-test and the other two tests. The results showed that the Scott bond test gave slightly higher values than the Z-test for the weakest paper, but that the value tended to be much higher for the stronger papers. On the other hand the Simulated Scott bond test tended to give lower values than the Z-test. High speed photography was used to reveal several energy consuming mechanisms in the Scott bond test that can explain why this test gave higher values than the Ztest. The lower values from the Simulated Scott bond values are more difficult to explain. At this stage we can suggest that the failure mechanism is different if the paper is delaminated by pure tension or by a gradual delamination as in the Scott bond test.

Experiment and Numerical Simulation of Extrudate Swell in the Polymer Extrusion Process

2011 ◽  
Vol 314-316 ◽  
pp. 401-404 ◽  
Author(s):  
Min Zhang ◽  
Chuan Zhen Huang ◽  
Guo Wen Chen ◽  
Yu Xi Jia
Keyword(s):  
Numerical Simulation ◽  
High Speed ◽  
Three Dimensional ◽  
Simulation Method ◽  
Extrusion Process ◽  
High Speed Photography ◽  
The Finite Element Method ◽  
Polymer Extrusion ◽  
Extrudate Swell ◽  
Rate Profile

The extrudate swell of the polymer extrusion process was studied with the experiment and simulation method. The extrudate swell process was recorded by the high-speed photography apparatus. The swell rate at the different time was calculated. It is found that the extrudate swell rate increase at the first five seconds. The maximum swell rate is about 4.37%. The three-dimensional numerical simulation model of the experiment die path was founded. The extrusion process including the extrudate swell was simulated used the Finite Element Method. Such simulated results as the velocity vector, the shear rate profile and the end of the swell zone were analyzed. The extrudate swell end got by the simulation is similar with the experiment result.

Numerical simulation on surface deformation for rotating mirrors of ultra-high-speed photography

2007 ◽  
Author(s):  
Hongbin Huang ◽  
Jingzhen Li ◽  
Xiangdong Gong ◽  
Fengshan Sun ◽  
Bin Hui
Keyword(s):  
Numerical Simulation ◽  
High Speed ◽  
Surface Deformation ◽  
High Speed Photography ◽  
Ultra High Speed

Numerical Simulation of Thixo-co-Extrusion of 7075/AZ91D Double-Layer Tubes

2016 ◽  
Vol 256 ◽  
pp. 119-125
Author(s):  
Xiao Wei Li ◽  
Kai Kun Wang ◽  
Jin Long Fu ◽  
Fei Yin
Keyword(s):  
Numerical Simulation ◽  
Double Layer ◽  
High Speed ◽  
New Technology ◽  
High Strength ◽  
Temperature Fields ◽  
Atomic Diffusion ◽  
Magnetic Pulse ◽  
High Speed Trains ◽  
Contact Pressures

Due to the excellent thermal conductivity and high strength of aluminum alloy and unique advantages containing shock absorbing, vibrations dampening and corrosion resistant of magnesium alloy, Al/Mg double-layer tubes have been widely utilized in household appliances, automobiles, aerospace industries, and high-speed trains in recent years. Conventionally, double-layer tubes are produced by welding, extrusion, hydroforming, magnetic pulse cladding. These processes are either complex or highly energy-consuming. To improve efficiency and reduce energy consumption, a new technology, thixo-co-extrusion (TCE), is put forward for production of double-layer tubes. In this paper, the thixo-co-extrusion of a 7075/AZ91D double-layer tube is investigated by numerical simulation. This study assesses the influences of extrusion velocity, the thickness ratios of two layers, the reheating temperatures of billets and the preheating temperature of die on the flow behaviors. The results show that the extrusion velocity and the thickness ratios significantly influence the contact pressures on the interface as well as the velocity fields. Besides, the reheating temperatures of billets and the preheating temperatures determine the distribution of temperature fields. Under the contact pressures and a certain temperature, atomic diffusion takes place on the interface between inner and outer layer, which leads to metallurgical bonding of the interface. The paper contributes to a better understanding of the thixo-co-extrusion technology for the production of double-layer tubes with desirable mechanical properties.

scholarly journals Using High-Speed Photography to Study Undercatch in Tipping-Bucket Rain Gauges*

2014 ◽  
Vol 31 (6) ◽  
pp. 1330-1336 ◽  
Author(s):  
Claude Duchon ◽  
Christopher Fiebrich ◽  
David Grimsley
Keyword(s):  
High Speed ◽  
Rain Rate ◽  
Slow Motion ◽  
Rain Gauge ◽  
The Other ◽  
High Speed Photography ◽  
High Speed Camera ◽  
Rain Gauges ◽  
Linear Correction ◽  
Rain Rates

Abstract To better understand the undercatch process associated with tipping-bucket rain gauges, a high-speed camera normally used in determining the structure of lightning was employed. The photo rate was set at 500 frames per second to observe the tipping of the bucket in a commonly used tipping-bucket rain gauge. The photos showed detail never seen before as the bucket tipped from one side to the other. Two fixed rain rates of 19.9 mm h−1 (0.78 in. h−1) and 175.2 mm h−1 (6.90 in. h−1), the minimum and maximum available, respectively, were used. The data from four tips at each rain rate were examined. The results show that the time from the beginning of a tip to the time the bucket assembly is horizontal—defined as the period during which undercatch occurs—was an average of 0.450 s for the eight cases. The average time for a complete tip was 0.524 s; thus, the vast majority of the time of a tip, 86%, is spent in undercatch mode. Because there was no apparent dependence of these times on rain rate, it should be possible to apply an accurate linear correction for undercatch as a function of rain rate given the time that undercatch occurs during a tip. Over all eight tips, the undercatch was found to be 0.98% for the 19.9 mm h−1 rate and 8.78% for the 175.2 mm h−1 rate. The procedure used to estimate the undercatch is described. Slow motion videos of the tipping of a bucket are available online.

scholarly journals DEM-CFD Simulation and Experiments on the Flow Characteristics of Particles in Vortex Pumps

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2444
Author(s):  
Xiongfa Gao ◽  
Weidong Shi ◽  
Ya Shi ◽  
Hao Chang ◽  
Ting Zhao
Keyword(s):  
Numerical Simulation ◽  
High Speed ◽  
Cfd Simulation ◽  
Flow Characteristics ◽  
Solid Particles ◽  
Experimental Results ◽  
High Speed Photography ◽  
Inlet Section ◽  
Impeller Blade ◽  
Vortex Pump

Due to their outstanding anti-clogging ability, vortex pumps have been gradually promoted and applied in recent years. However, when transporting sewage containing solids, they will still encounter problems such as partial clogging, overwork wear, etc., therefore, it is particularly important to master the flow characteristics of solid particles in the vortex pump. In this paper, the Discrete Element Model-Computational Fluid Dynamics (DEM-CFD) coupled calculation method is introduced into the numerical simulation of vortex pumps and particles with diameters of 1, 2 and 3 mm and concentrations of 1% and 5%, were subjected to numerical simulation and study of the flow characteristics of the particles, then rapeseed was used to represent solid particles in tests. It was obvious that the CFD results were in good agreement with the experimental results, whereby the high speed photography experimental results of the pump inlet section show that the experimental results are consistent with the numerical simulation results. The results show that there are three typical movement tracks of solid particles in the vortex pump: in Track A particles flow through the impeller and enter the volute by the through flow, in Track B particles go directly into the volute through the lateral cavity under the influence of circulation flow and in Track C the particles enter the impeller from the front cover end area of the impeller blade inlet and then into the volute through the back half area of blade. It can be found that the particles are mainly distributed at the back of the volute.

A Study of White Smoke Generation and Its Numerical Simulation

1993 ◽  
Vol 207 (2) ◽  
pp. 101-106 ◽  
Author(s):  
T Shiozaki ◽  
T Otani ◽  
I Joko
Keyword(s):  
Numerical Simulation ◽  
High Speed ◽  
Experimental Results ◽  
Fuel Spray ◽  
High Speed Photography ◽  
Visualization Technique ◽  
Lean Mixture ◽  
Smoke Generation

A mechanism of white smoke generation is clarified by a visualization technique using high-speed photography. The adhered fuel spray on the wall of the cavity, the fuel in the lean mixture region, the spilled fuel from the combustion cavity and the fuel from the sac volume of the nozzle tip are converted to the white smoke late in the expansion stroke. Numerical simulation is also conducted and its results coincide well with experimental results.

A practical review study on shaped charge in the last two decades (2000–2020)

2021 ◽  
pp. 204141962110179
Author(s):  
Hossein Mehmannavaz ◽  
Ali Ramezani ◽  
MohammadAmin Nabakhteh ◽  
Gholamhossein Liaghat
Keyword(s):  
Double Layer ◽  
Shaped Charge ◽  
The Other ◽  
Explosion Energy ◽  
Dual Mode ◽  
Other Hand ◽  
Linear Shaped Charge ◽  
Different Types ◽  
Review Study ◽  
Underwater Targets

Shaped charges are devices used for cutting or penetrating different aerial, on land, and underwater targets, based on the concentration of the explosion energy to the liner. The purpose of this study is to present a practical review of the studies related to shaped charges in the last twenty years (2000–2020). In this regard, these studies have been reviewed in two different categories for ordinary and advanced shaped charges. In the case of ordinary shaped charges, different aspects including shaped charges against different targets, different types of shaped charges (such as linear shaped charge and explosively formed penetrators), and theoretical advancements are presented. On the other hand, the new kinds of shaped charges developed for a specific purpose are introduced in the case of advanced shaped charges. The survey of the literature indicates that different concepts such as cut-off velocity and theoretical applicability of hydrodynamics theory in shaped charge penetration still Requires effort. Also, few studies have been focused on new shaped charges, such as hyper-velocity shaped charges, annular and dual-mode ones; and the field is still open for further progress. Besides, some of these new shaped-charges, such as double-layer shaped charges, are not realistic enough to be produced for practical purposes or the market.

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