Simulation of a Group Impact on a Heterogeneous Target of Finite Thickness

2021 ◽  
Vol 14 (6) ◽  
pp. 700-711
Author(s):  
Alexander E. Kraus ◽  
◽  
Evgeny I. Kraus ◽  
Ivan I. Shabalin
Keyword(s):  
Numerical Simulation ◽  
High Speed ◽  
Finite Thickness ◽  
Target Volume ◽  
Maximum Mass ◽  
Aluminum Target ◽  
Simulation Results

Numerical simulation of the processes of high-speed loading of homogeneous and heteroge- neous targets by single projectiles, as well as by a group of projectiles with the same parameters in mass and momentum, has been carried out. Based on a comparison of the numerical simulation results for loading targets with different sets of projectiles, it is found that a projectile in the form of a ring knocks out the maximum hole in the target in terms of geometric dimensions, while a set of seven small disks removes the maximum mass from the target. The ring impact forms a continuous spall plate, which outruns the cloud of fragments of the destroyed material. Adding more than 5% of ceramics to the aluminum target volume does not allow the projectiles to penetrate through

Numerical Simulation of Supercavity Shape Design of High-Speed Projectile

2012 ◽  
Vol 466-467 ◽  
pp. 1041-1044
Author(s):  
Wen Jian Ying ◽  
Jian Hou ◽  
Ping Wei
Keyword(s):  
Numerical Simulation ◽  
Drag Coefficient ◽  
High Speed ◽  
Slenderness Ratio ◽  
Axisymmetric Body ◽  
Panel Method ◽  
Shape Design ◽  
Shape Model ◽  
Simulation Results ◽  
The Difference

In order to investigate the drag characteristics of high speed projectile in the states of supercavitation shape, this article presents the shape design’s method and gist of the underwater high-speed projectile. The first, the shape model is presented that is based on the potential panel method to the slender axisymmetric body. The second, the effect is analyzed comparatively that is from the difference shape to the supercavitation. The simulation results show that smaller drag coefficient of the projectile can be obtained by increasing the slenderness ratio and the barycenter position.

Numerical Simulation of Multi-Angle Incidence Aluminum Composite Targets with 7.62mm Piercing Armor

2014 ◽  
Vol 602-605 ◽  
pp. 562-565
Author(s):  
Yu Lei Li ◽  
Jin Jun Tang ◽  
Xiao Yu Jin ◽  
Qun Wang ◽  
Zheng Ren
Keyword(s):  
Numerical Simulation ◽  
Aluminum Alloy ◽  
Material Model ◽  
Element Model ◽  
Target Plate ◽  
Aluminum Composite ◽  
3D Finite Element ◽  
Aluminum Target ◽  
Simulation Results ◽  
The Impact

To calculate the multi-angle penetration, this paper established a 3D finite element model of aluminum alloy plates and 7.62mm armor-piercing by using LS-DYNA software and the Johnson-Cook material model. The process of bullet penetrating 20mm thickness target with different angles of incidence was carried out. The impact of combinations on composite targets resistance projectile penetrating ability was analyzed. Simulation results show that,ballistic of composite targets can be between two aluminum target plate, clearly different combinations of composite targets for resistance to different angles of incidence between projectile penetrating relationship.

Experimental Study and Numerical Simulation on Slamming of High-Speed Trimaran

2010 ◽  
Author(s):  
Xiangshao Kong ◽  
Weiguo Wu ◽  
Xiaobian Li ◽  
Shuangxi Xu ◽  
Yuanzhou Zheng ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
High Speed ◽  
Element Model ◽  
Research Field ◽  
Simulation Software ◽  
Scale Model ◽  
Nonlinear Simulation ◽  
Simulation Results ◽  
Reduced Scale ◽  
Cross Structure

The study on slamming of high speed trimaran is a very complicated and significant topic. Ship slamming is a nonlinear unsteady problem in which dynamic boundary and coupling among structure, air and water should be considered. It is a key issue in the ship research field. Unlike the slamming of ordinary monohull, trimaran slamming include not only main hull bottom slamming, but also slamming of trimaran cross structure, which makes trimaran slamming more complicated. In this paper, a reduced scale model of trimaran was constructed and an experiment was carried out in order to study the slamming pressure distribution on main hull and cross structure. By using nonlinear simulation software Autodyn, a finite element model was established to simulate the process that trimaran model enters into water. The accuracy and reliability of numerical simulation is validated by comparing experimental data and numerical simulation results. Furthermore, some valuable conclusions on trimaran slamming are obtained.

scholarly journals Experimental and Numerical Study of Water Entry Supercavity Influenced by Turbulent Drag-Reducing Additives

2014 ◽  
Vol 6 ◽  
pp. 280643 ◽  
Author(s):  
Chen-Xing Jiang ◽  
Feng-Chen Li
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
High Speed ◽  
Numerical Study ◽  
Ccd Camera ◽  
Water Entry ◽  
Multiphase Model ◽  
Turbulent Drag ◽  
Unsteady Rans ◽  
Simulation Results

The configurational and dynamic characteristics of water entry supercavities influenced by turbulent drag-reducing additives were studied through supercavitating projectile approach, experimentally and numerically. The projectile was projected vertically into water and aqueous solution of CTAC with weight concentrations of 100, 500, and 1000 ppm, respectively, using a pneumatic nail gun. The trajectories of the projectile and the supercavity configuration were recorded by a high-speed CCD camera. Besides, water entry supercavities in water and CTAC solution were numerically simulated based on unsteady RANS scheme, together with application of VOF multiphase model. The Cross viscosity model was adopted to represent the fluid property of CTAC solution. It was obtained that the numerical simulation results are in consistence with experimental data. Numerical and experimental results all show that the length and diameter of supercavity in drag-reducing solution are larger than those in water, and the drag coefficient is smaller than that in water; the maintaining time of supercavity is longer in solution as well. The surface tension plays an important role in maintaining the cavity. Turbulent drag-reducing additives have the potential in enhancement of supercavitation and drag reduction.

Avalanche Features in Silicon Schottky-FETs in Accordance with Numerical Simulation Results

2006 ◽  
Vol 65 (16) ◽  
pp. 1533-1546
Author(s):  
Yu. Ye. Gordienko ◽  
S. A. Zuev ◽  
V. V. Starostenko ◽  
V. Yu. Tereshchenko ◽  
A. A. Shadrin
Keyword(s):  
Numerical Simulation ◽  
Simulation Results

Numerical simulation of high-speed civil transport inlet operability with angle of attack

AIAA Journal ◽  
1998 ◽  
Vol 36 ◽  
pp. 1223-1229
Author(s):  
Ge-Cheng Zha ◽  
Doyle Knight ◽  
Donald Smith ◽  
Martin Haas
Keyword(s):  
Numerical Simulation ◽  
High Speed ◽  
Angle Of Attack

Numerical Simulation of High-Speed Crack Propagating and Branching Phenomena

2016 ◽  
Vol 37 (7) ◽  
pp. 729-739
Author(s):  
GU Xin-bao ◽  
◽  
ZHOU Xiao-ping ◽  
XU Xiao ◽  
Keyword(s):  
Numerical Simulation ◽  
High Speed

Tail shapes lead to different propulsive mechanisms in the body/caudal fin undulation of fish

2020 ◽  
pp. 095440622096768
Author(s):  
Jialei Song ◽  
Yong Zhong ◽  
Ruxu Du ◽  
Ling Yin ◽  
Yang Ding
Keyword(s):  
Numerical Simulation ◽  
Aspect Ratio ◽  
High Efficiency ◽  
The Body ◽  
Caudal Fin ◽  
Fish Model ◽  
Swimming Efficiency ◽  
Simulation Results ◽  
Propulsive Mechanism ◽  
High Depth

In this paper, we investigate the hydrodynamics of swimmers with three caudal fins: a round one corresponding to snakehead fish ( Channidae), an indented one corresponding to saithe ( Pollachius virens), and a lunate one corresponding to tuna ( Thunnus thynnus). A direct numerical simulation (DNS) approach with a self-propelled fish model was adopted. The simulation results show that the caudal fin transitions from a pushing/suction combined propulsive mechanism to a suction-dominated propulsive mechanism with increasing aspect ratio ( AR). Interestingly, different from a previous finding that suction-based propulsion leads to high efficiency in animal swimming, this study shows that the utilization of suction-based propulsion by a high- AR caudal fin reduces swimming efficiency. Therefore, the suction-based propulsive mechanism does not necessarily lead to high efficiency, while other factors might play a role. Further analysis shows that the large lateral momentum transferred to the flow due to the high depth of the high- AR caudal fin leads to the lowest efficiency despite the most significant suction.

scholarly journals Experiment and simulation about the effect of wear-ring abrasion on the performance of a marine centrifugal pump

2021 ◽  
Vol 13 (2) ◽  
pp. 168781402199811
Author(s):  
Wu Xianfang ◽  
Du Xinlai ◽  
Tan Minggao ◽  
Liu Houlin
Keyword(s):  
Numerical Simulation ◽  
Centrifugal Pump ◽  
Pressure Pulsation ◽  
Vibration Velocity ◽  
Test Results ◽  
Obvious Effect ◽  
Performance Change ◽  
Pump Test ◽  
Simulation Results ◽  
Axis Passing

The wear-ring abrasion can cause performance degradation of the marine centrifugal pump. In order to study the effect of front and back wear-ring clearance on a pump, test and numerical simulation were used to investigate the performance change of a pump. The test results show that the head and efficiency of pump decrease by 3.56% and 9.62% respectively at 1.0 Qd due to the wear-ring abrasion. Under 1.0 Qd, with the increase of the front wear-ring the vibration velocity at pump foot increases from 0.4 mm/s to 1.0 mm/s. The axis passing frequency (APF) at the measuring points increases significantly and there appears new characteristic frequency of 3APF and 4APF. The numerical simulation results show that the front wear-ring abrasion affects the flow at the inlet of the front chamber of the pump and impeller passage. And the back wear-ring abrasion has obvious effect on the flow in the back chamber of the pump and impeller passage, while the multi-malfunction of the front wear-ring abrasion and back wear-ring abrasion has the most obvious effect on the flow velocity and flow stability inside pump. The pressure pulsation at Blade Passing Frequency (BPF) of the three schemes all decrease with the increase of the clearance.

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