期刊文献+
共找到7篇文章
< 1 >
每页显示 20 50 100
Jet formation and penetration mechanism of W typed shaped charge 被引量:7
1
作者 Cheng Wang Fenglei Huang Jianguo Ning State Key Laboratory of Explosion Science and Technology,Beijing Institute of Technology, 100081 Beijing, China 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2009年第1期107-120,共14页
Existing classical shaped charges are well known for their longer jets capable of achieving large hole depth to hole diameter ratios in metallic targets. However, in some situations, there arises demand to obtain 1:1... Existing classical shaped charges are well known for their longer jets capable of achieving large hole depth to hole diameter ratios in metallic targets. However, in some situations, there arises demand to obtain 1:1 ratio for hole depth to hole diameter which is beyond normal shaped charges capability. A new variant of shape charge, named W typed shape charge (WSC), is proposed in this paper, which can meet the demand of 1:1 ratio, and is based on the geometry that can produce annular jets upon proper initiation scheme. In this paper, we present formation and penetration results of WSC based on three different schemes. We also show that not all WSC designs can form annular jets, only annularly initiated WSC, which also fulfils the "Internal-External Liners Equal-Impulse" criterion, has the capability to form annular jet. The experimental and numerical results show that when the ratio between annular initiation ring diameter and the charge diameter is 0.75, an annular jet is formed, which was also supported by high speed photographs performed in vacuum. 2D numerical simulations are performed with indigenously developed simulation software, where Eulerian approach with multi-material interface tracking algorithm is utilized, to find various mechanisms involved during jet formation process. The calculation results are found in good agreement with the experimental results, indicating that the interface treatment algorithm proposed in this paper can not only deal with large deformation problem, but also depict clearly the variation of materials interface. It is especially suitable for simulation of the process from liner collapse to formation of shaped charge jet. 展开更多
关键词 WSC Annular jet interface tracking Numerical simulation
下载PDF
An experimental analysis of situation awareness for cockpit display interface evaluation based on flight simulation 被引量:24
2
作者 Wei Hengyang Zhuang Damin +1 位作者 Wanyan Xiaoru Wang Qun 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2013年第4期884-889,共6页
Aircraft cockpit display interface (CDI) is one of the most important human-machine interfaces for information perceiving. During the process of aircraft design, situation awareness (SA) is frequently considered t... Aircraft cockpit display interface (CDI) is one of the most important human-machine interfaces for information perceiving. During the process of aircraft design, situation awareness (SA) is frequently considered to improve the design, as the CDI must provide enough SA for the pilot to maintain the flight safety. In order to study the SA in the pilot-aircraft system, a cockpit flight simulation environment is built up, which includes a virtual instrument panel, a flight visual display and the corresponding control system. Based on the simulation environment, a human-in-the-loop experiment is designed to measure the SA by the situation awareness global assessment technique (SAGAT). Through the experiment, the SA degrees and heart rate (HR) data of the subjects are obtained, and the SA levels under different CDI designs are analyzed. The results show that analyzing the SA can serve as an objective way to evaluate the design of CDI, which could be proved from the consistent HR data. With this method, evaluations of the CDI design are performed in the experimental flight simulation environment, and optimizations could be guided through the analysis. 展开更多
关键词 Cockpit display interface Design evaluation Flight simulation Heart rate SAGAT Situation awareness
原文传递
DNS analysis of incipient drop impact dynamics using an accurate level set method 被引量:2
3
作者 Min Chai Kun Luo +2 位作者 Changxiao Shao Song Chen Jianren Fan 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2017年第1期1-10,共10页
A series of 2D direct numerical simulations were performed with an accurate level set method for single drop impacts.The adopted ACLS method was validated to be efficient with perfect mass conservation in both normal ... A series of 2D direct numerical simulations were performed with an accurate level set method for single drop impacts.The adopted ACLS method was validated to be efficient with perfect mass conservation in both normal and oblique impacts.A square-root correction for neck bases was modified in accuracy as well as scope of applications.In addition,process of jet formation and evolution was studied to reveal internal dynamics in drop impacts.It's found that pressure gradient and vortex are coexisting and completive reasons for jet topology while the inclined angle has a significant effect on them.Mechanisms of jet formation and evolution are different in the front and back necks.With the help of PDF distribution and correction calculation,a compromise in the competition is observed.This work lays a solid foundation for further studies of dynamics in gas-liquid flows. 展开更多
关键词 Numerical simulation Accurate level set Gas-liquid flow interface Mechanism completion Compromise
下载PDF
Water-trapping and drag-reduction effects of fish Ctenopharyngodon idellus scales and their simulations 被引量:7
4
作者 WU LiYan JIAO ZhiBin +3 位作者 SONG YuQiu REN WenTao NIU ShiChao HAN ZhiWu 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2017年第7期1111-1117,共7页
In the last decades, surface drag reduction has been re-emphasized because of its practical values in engineering applications,including vehicles, aircrafts, ships, and fuel pipelines. The bionic study of drag reducti... In the last decades, surface drag reduction has been re-emphasized because of its practical values in engineering applications,including vehicles, aircrafts, ships, and fuel pipelines. The bionic study of drag reduction has been attracting scholars' attentions. Here, it was determined that the delicate microstructures on the scales of the fish Ctenopharyngodon idellus exhibit remarkable drag-reduction effect. In addition, the underlying drag-reduction mechanism was carefully investigated. First,exceptional morphologies and structures of the scales were observed and measured using a scanning electron microscope and3-dimensional(3D) microscope. Then, based on the acquired data, optimized 3D models were created. Next, the mechanism of the water-trapping effect of these structures was analyzed through numerical simulations and theoretical calculations. It was determined that there are many microcrescent units with certain distributions on its surface. In fact, these crescents are effective in generating the "water-trapping" effect and forming a fluid-lubrication film, thus reducing the skin friction drag effectively.Contrasting to a smooth surface, the dynamics finite-element analysis indicated that the maximum drag-reduction rate of a bionic surface is 3.014% at 0.66 m/s flow rate. This study can be used as a reference for an in-depth analysis on the bionic drag reduction of boats, underwater vehicles, and so forth. 展开更多
关键词 water trapping structure drag reduction surface fish scales simulations bionic surface and interface
原文传递
Combination of direct-forcing fictitious domain method and sharp interface method for dielectrophoresis of particles
5
作者 Yang Shi Zhaosheng Yu Xueming Shao 《Particuology》 SCIE EI CAS CSCD 2010年第4期351-359,共9页
In this paper, we combine the direct-forcing fictitious domain (DF/FD) method and the sharp interface method to resolve the problem of particle dielectrophoresis in two dimensions. The flow field and the motion of p... In this paper, we combine the direct-forcing fictitious domain (DF/FD) method and the sharp interface method to resolve the problem of particle dielectrophoresis in two dimensions. The flow field and the motion of particles are solved with the DF/FD method, the electric field is solved with the sharp inter- face method, and the electrostatic force on the particles is computed using the Maxwell stress tensor method. The proposed method is validated via three problems: effective conductivity of particle compos- ite between two planar plates, cell trapping in a channel, and motion of particles due to both conventional and traveling wave dielectrophoretic forces. 展开更多
关键词 Direct-forcing fictitious domain method Sharp interface methodMaxwell stress tensor method Dielectrophoresis Direct numerical simulation Cell trapping
原文传递
Structures,properties,and challenges of emerging 2D materials in bioelectronics and biosensors 被引量:3
6
作者 Fan Chen Qing Tang +7 位作者 Tian Ma Bihui Zhu Liyun Wang Chao He Xianglin Luo Sujiao Cao Lang Ma Chong Cheng 《InfoMat》 SCIE CAS 2022年第5期102-138,共37页
Bioelectronics are powerful tools for monitoring and stimulating biological and biochemical processes,with applications ranging from neural interface simulation to biosensing.The increasing demand for bioelectronics h... Bioelectronics are powerful tools for monitoring and stimulating biological and biochemical processes,with applications ranging from neural interface simulation to biosensing.The increasing demand for bioelectronics has greatly promoted the development of new nanomaterials as detection platforms.Recently,owing to their ultrathin structures and excellent physicochemical properties,emerging two-dimensional(2D)materials have become one of the most researched areas in the fields of bioelectronics and biosensors.In this timely review,the physicochemical structures of the most representative emerging 2D materials and the design of their nanostructures for engineering highperformance bioelectronic and biosensing devices are presented.We focus on the structural optimization of emerging 2D material-based composites to achieve better regulation for enhancing the performance of bioelectronics.Subsequently,the recent developments of emerging 2D materials in bioelectronics,such as neural interface simulation,biomolecular/biomarker detection,and skin sensors are discussed thoroughly.Finally,we provide conclusive views on the current challenges and future perspectives on utilizing emerging 2D materials and their composites for bioelectronics and biosensors.This review will offer important guidance in designing and applying emerging 2D materials in bioelectronics,thus further promoting their prospects in a wide biomedical field. 展开更多
关键词 BIOELECTRONICS biosensors emerging 2D materials nanostructures and properties neural interfaces simulation
原文传递
Micromechanical Behavior and Failure Mechanism of F / B Multi-phase High Performance Steel 被引量:7
7
作者 Cun-jiang TANG Shi-long LIU Cheng-jia SHANG 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2016年第5期489-494,共6页
The deformation and micro-voids formation mechanisms in ferrite / bainite( F / B) multi-phase steel with the volume fraction of bainite less than 50% were studied by numerical simulation and experimental observation... The deformation and micro-voids formation mechanisms in ferrite / bainite( F / B) multi-phase steel with the volume fraction of bainite less than 50% were studied by numerical simulation and experimental observation. The results show that the micro-strain concentrates at the soft / hard phase( F / B) interface in the multi-phase steel,which should be correlated with the mechanism of incoordinate deformation. During the necking of the steel,the micro-voids initially form around the F / B interface,which also form in ferrite and bainite with the severe strain. The micro-voids in bainite are more dense and finer than those in ferrite. The failure mechanism of bainite is the coalescence of micro-voids,and the failure mechanism of ferrite is the growth and tearing of micro-voids. Due to the different failure mechanisms of ferrite and bainite,a suitable part of soft phase would be beneficial to the capability of anti-failure of F / B multi-phase steel during the ductile fracture. 展开更多
关键词 ferrite / bainite multi-phase steel numerical simulation ferrite / bainite interface micro-strain micro-void failure mechanism soft phase
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部