Experimental and Numerical Research of Small Metal Disk Driven by Explosive

2011 ◽  
Vol 673 ◽  
pp. 301-305
Author(s):  
Hideki Hamashima ◽  
Shiro Kubota ◽  
Tei Saburi ◽  
Yuji Ogata

In order to investigate the hazard of the fragments caused by the explosion damage, the simply-simulated explosion experiment and numerical simulation were conducted. In this study, the behavior of the disk supposing the fragment driven by an explosive was investigated. In the experiment, the optical observation using a high-speed camera was performed to obtain the basic data about a disk, such as flying velocity. Moreover, numerical simulation was performed using analysis software LS-DYNA. Comparison and examination for experimental results and numerical results were reported.

Author(s):  
Marcio Yamamoto ◽  
Sotaro Masanobu ◽  
Satoru Takano ◽  
Shigeo Kanada ◽  
Tomo Fujiwara ◽  
...  

In this article, we present the numerical analysis of a Free Standing Riser. The numerical simulation was carried out using a commercial riser analysis software suit. The numerical model’s dimensions were the same of a 1/70 reduced scale model deployed in a previous experiment. The numerical results were compared with experimental results presented in a previous article [1]. Discussion about the model and limitations of the numerical analysis is included.


2021 ◽  
Vol 9 (6) ◽  
pp. 619
Author(s):  
Chunlong Ma ◽  
Dongyan Shi ◽  
Chao Li ◽  
Dongze He ◽  
Guangliang Li ◽  
...  

In this study, a compressible three-phase homogeneous model was established using ABAQUS/Explicit. These models can numerically simulate the pulsation process of cavitation bubbles in the free field, near the flat plate target, and near the curved boundary target. At the same time, these models can numerically simulate the strong nonlinear interaction between the cavitation bubble and its nearby wall boundaries. The mutual flow of liquid and gas and fluid solid coupling were solved by the Euler domain in simulation. The results of the numerical simulation were verified by comparing them with the experimental results. In this study, we used electric spark bubbles to represent cavitation bubbles. A high-speed camera was used to record the pulsation process of cavitation bubbles. This study first verified the pulsation process of cavitation bubbles in the free field, because it was the simplest case. Then we verified the interaction process between cavitation bubbles and different wall boundaries. In order to further confirm the credibility of the numerical simulation results, for each wall surface, this study used two burst distances (10 mm and 25 mm) for simulation verification. The numerical model established in this study could effectively simulate the pulsation characteristics of cavitation bubbles, such as the formation of jets and annular bubbles. After verification, the simulated cavitation bubble was almost the same as the cavitation bubble captured by the high-speed camera in the experiment in terms of time, volume, and shape. In this study, a detailed velocity field of the cavitation bubble collapse stage was obtained, which laid down the foundation for the study of the strong nonlinear interaction between the cavitation bubble and the target plates of different shapes. Compared with the experimental results, we found that the numerical model established by the simulation could accurately simulate the bubble pulsation and jet formation processes. In the experiment, the interval time for the bubble pictures taken by the high-speed camera was 41.66 μs per frame. Using a numerical model, the bubble pulsation process can be simulated at an interval of 1 µs per frame. Therefore, the numerical model established by the simulation could show the movement characteristics of the cavitation bubble pulsation process in more detail.


2012 ◽  
Vol 160 ◽  
pp. 77-81
Author(s):  
Jing Jing Tian ◽  
Lei Han

Kick-up phenomenon during looping is an important factor in thermosonic wire bonding. In this study, the loping process during wire bonding was recorded by using high-speed camera, and wire profiles evolution was obtained from images sequence by image processing method. With a polynomial fitting, the wire loop profiling was described by the curvature changing, and kick-up phenomenon on gold wire was found between the instant of 290th frame(0.0537s) to 380th frame (0.0703s), the change of curvature is divided into three phases, a looping phase, a mutation phase and a kick-up phase. While in the kick-up phase, the kick up phenomenon is the most obvious. These experimental results were useful for in-depth study of kick-up phenomenon by simulation.


2012 ◽  
Vol 510 ◽  
pp. 500-506
Author(s):  
Chang Hai Chen ◽  
Xi Zhu ◽  
Hai Liang Hou ◽  
Li Jun Zhang ◽  
Ting Tang

To explore the deflagration possibility of the warship cabin filled with fuel oil under impact of high-speed fragments in the condition of room temperature, experiments were carried out employing the small aluminium oilcans filled with fuel oil. Response processes of the oilcans were observed with the help of a high-speed camera. The disintegration as well as flying scattering of the oilcans were analyzed. The reasons for atomization of the fuel oils were presented. Finally, the deflagration possibility of warship oil cabin was analyzed. Results show that the pressure inside the oilcan is quite great under the impact of the high-speed fragment, which makes the oilcan disintegration and flying scattering. Simultaneously, fuel oils inside the oilcans are atomized quickly followed by ejected in front and back directions. Under the same condition as in present tests, deflagration will not occur for fuel oils used by warships. Experimental results will provide valuable references for the deflagration analysis of warship fuel oil cabins subjected to the impact of high-velocity fragments.


Author(s):  
Alexandros Nikolakakis ◽  
Ioannis Kontolatis ◽  
Nicholas Cherouvim ◽  
Panagiotis Chatzakos ◽  
Evangelos Papadopoulos

This paper presents a multipart pronking/bounding controller for a quadruped robot, as well as the corresponding experimental results. The controller achieves given apex height and forward velocity in a quadruped robot with only one actuator per leg. A quadruped is designed and built and described in some detail. Experimental results obtained using internal sensors and high-speed camera captions show that the implemented quadruped robot performs pronking gaits and achieves bounding gaits with the desired characteristics.


2018 ◽  
Vol 300 ◽  
pp. 49-51
Author(s):  
Grzegorz Bogiel ◽  
◽  
Paweł Dudek ◽  

The phenomenon of bullet reflection from a ballistic wall has not yet been described or investigated in forensic practice. The article presents the method of conducting such tests, including the results thereof. The tests were carried out using a high-speed camera, video analysis software and a Doppler radar. As a result of the study, the velocities of bullets for which the phenomenon of reflection from the ballistic wall is observed, were determined.


1986 ◽  
Vol 108 (2) ◽  
pp. 187-193 ◽  
Author(s):  
M. L. Celestina ◽  
R. A. Mulac ◽  
J. J. Adamczyk

This paper presents the results of a numerical simulation of the time-averaged inviscid flow field through the blade rows of a multiblade row turboprop configuration. The governing equations are outlined along with a discussion of the solution procedure and coding strategy. Numerical results obtained from a simulation of the flow field through a modern high-speed turboprop will be shown.


2019 ◽  
Vol 11 (5) ◽  
pp. 723-736
Author(s):  
Radek Doubrava ◽  
Martin Oberthor ◽  
Petr Bělský ◽  
Jan Raška

Purpose The purpose of this paper is to describe the approach for the design of a jet engine composite air inlet for a new generation of jet trainer aircraft from the perspective of airworthiness requirements regarding high-speed impact resistance. Design/methodology/approach Validated numerical simulation was applied to flat test panels. The final design was optimised and verified by validated numerical simulation and verified by testing on a full-scale demonstrator. High-speed camera measurement and non-destructive testing (NDT) results were used for the verification of the numerical models. Findings The test results of flat test panels confirmed the high durability of the composite structure during inclined high-speed impact with a near-real jet inlet load boundary condition. Research limitations/implications Owing to the sensitivity of the composite material on technology production, the results are limited by the material used and the production technology. Practical implications The application of flat test panels for the verification and tuning of numerical models allows optimised final design of the air inlet and reduces the risk of structural non-compliance during verification tests. Originality/value Numerical models were verified for simulation of the real composite structure based on high-speed camera results and NDT inspection after impact. The proposed numerical model was simplified for application in a real complex design and reduced calculation time.


2014 ◽  
Vol 590 ◽  
pp. 37-41
Author(s):  
Yu Min Su ◽  
Yun Hui Li ◽  
Hai Long Shen

In order to forecast the sailing response of planing craft at high speed rapidly and accurately, CFD code Fine/Marine solver was used to calculate the resistance and sailing attitude of a high-speed planing craft, then the numerical results were compared with experimental results and empirical formula results. The results showed that resistance error calculated by Fine/Marine was between 5% and 10%, trim and heave results were in good agreement with experimental results, and had greater accuracy compared with the empirical formula results. The feasibility of this numerical simulation method was validated and this method provided an effect performance evaluation method for new designing planing crafts.


Sign in / Sign up

Export Citation Format

Share Document