scholarly journals The energy density in a one-dimensional cavity with two moving boundaries

2003 ◽  
Vol 52 (11) ◽  
pp. 2762
Author(s):  
Li Ling ◽  
Li Bo-Zang
Keyword(s):  
Energy Density ◽  
Moving Boundaries ◽  
One Dimensional

Numerical simulation of gas-solid two-phase reaction flow with multiple moving boundaries

2015 ◽  
Vol 25 (2) ◽  
pp. 375-390 ◽  
Author(s):  
Qiao Luo ◽  
Xiaobing Zhang
Keyword(s):  
Numerical Simulation ◽  
Physical Phenomenon ◽  
Great Influence ◽  
Moving Boundaries ◽  
Charge Weight ◽  
Phase Reaction ◽  
Two Phase ◽  
Content Type ◽  
One Dimensional ◽  
Chamber Volume

Purpose – In engineering applications, gas-solid two-phase reaction flow with multi-moving boundaries is a common phenomenon. The launch process of multiple projectiles is a typical example. The flow of adjacent powder chambers is coupled by projectile’s motion. The purpose of this paper is to study this flow by numerical simulation. Design/methodology/approach – A one-dimensional two-phase reaction flow model and MacCormack difference scheme are implemented in a computational code, and the code is used to simulate the launch process of a system of multiple projectiles. For different launching rates and loading conditions, the simulated results of the launch process of three projectiles are obtained and discussed. Findings – At low launching rates, projectiles fired earlier in the series have little effect on the launch processes of projectiles fired later. However, at higher launching rates, the projectiles fired first have a great influence on the launch processes of projectiles fired later. As the launching rate increases, the maximum breech pressure for the later projectiles increases. Although the muzzle velocities increase initially, they reach a maximum at some launching rate, and then decrease rapidly. The muzzle velocities and maximum breech pressures of the three projectiles have an approximate linear relationship with the charge weight, propellant web size and chamber volume. Originality/value – This paper presents a prediction tool to understand the physical phenomenon of the gas-solid two-phase reaction flow with multi-moving boundaries, and can be used as a research tool for future interior ballistics studies of launch system of multiple projectiles.

High-Energy-Density Polymer Nanocomposites Composed of Newly Structured One-Dimensional BaTiO3@Al2O3 Nanofibers

2017 ◽  
Vol 9 (4) ◽  
pp. 4024-4033 ◽  
Author(s):  
Zhongbin Pan ◽  
Lingmin Yao ◽  
Jiwei Zhai ◽  
Dezhou Fu ◽  
Bo Shen ◽  
...  
Keyword(s):  
Energy Density ◽  
Polymer Nanocomposites ◽  
High Energy ◽  
High Energy Density ◽  
One Dimensional

scholarly journals On the Definition of Energy Flux in One-Dimensional Chains of Particles

Entropy ◽  
2019 ◽  
Vol 21 (11) ◽  
pp. 1036
Author(s):  
Paolo De Gregorio
Keyword(s):  
Energy Density ◽  
Integral Operator ◽  
Energy Flux ◽  
Ad Hoc ◽  
The Other ◽  
Energy Density Distribution ◽  
One Dimensional ◽  
Integral Quantity ◽  
Definition Of ◽  
Local Quantity

We review two well-known definitions present in the literature, which are used to define the heat or energy flux in one dimensional chains. One definition equates the energy variation per particle to a discretized flux difference, which we here show it also corresponds to the flux of energy in the zero wavenumber limit in Fourier space, concurrently providing a general formula valid for all wavelengths. The other relies somewhat elaborately on a definition of the flux, which is a function of every coordinate in the line. We try to shed further light on their significance by introducing a novel integral operator, acting over movable boundaries represented by the neighboring particles’ positions, or some combinations thereof. By specializing to the case of chains with the particles’ order conserved, we show that the first definition corresponds to applying the differential continuity-equation operator after the application of the integral operator. Conversely, the second definition corresponds to applying the introduced integral operator to the energy flux. It is, therefore, an integral quantity and not a local quantity. More worryingly, it does not satisfy in any obvious way an equation of continuity. We show that in stationary states, the first definition is resilient to several formally legitimate modifications of the (models of) energy density distribution, while the second is not. On the other hand, it seems peculiar that this integral definition appears to capture a transport contribution, which may be called of convective nature, which is altogether missed by the former definition. In an attempt to connect the dots, we propose that the locally integrated flux divided by the inter-particle distance is a good measure of the energy flux. We show that the proposition can be explicitly constructed analytically by an ad hoc modification of the chosen model for the energy density.

Topologically distributed one-dimensional TiO2 nanofillers maximize the dielectric energy density in a P(VDF-HFP) nanocomposite

2020 ◽  
Vol 8 (35) ◽  
pp. 18244-18253
Author(s):  
Xiaoru Liu ◽  
Penghao Hu ◽  
Jinyao Yu ◽  
Mingzhi Fan ◽  
Xumin Ji ◽  
...  
Keyword(s):  
Energy Density ◽  
One Dimensional

The dielectric energy density of a P(VDF-HFP) nanocomposite is greatly enhanced via the use of one-dimensional TiO2 nanofillers with a topological distribution.

SOME NOTES ON LOW-DIMENSIONAL ELASTIC THEORIES OF BIO- AND NANO-STRUCTURES

2010 ◽  
Vol 24 (23) ◽  
pp. 2403-2412 ◽  
Author(s):  
XIAO-HUA ZHOU
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Energy Density ◽  
Helix Angle ◽  
Dimensional Structure ◽  
One Dimensional ◽  
Nano Structures ◽  
Multi Walled Carbon Nanotubes ◽  
Low Dimensional ◽  
Walled Carbon Nanotubes

The shapes of DNA, carbon nanotube (CNT) and vesicle are determined by the minimum of their elastic energy. Two central results about the low-dimensional elastic structure are reported here. Firstly, if the energy density of a one-dimensional structure is only related to its curvature, we generally find that a helix solution with the helix angle θ = ±π/4 will have zero total energy. Secondly, with the fixed length and radii, the helical multi-walled carbon nanotubes (MWNTs) and DNA will have the lowest energy when the helix angle θ = ±π/3.

Active control of energy density in a one-dimensional waveguide: A cautionary note (L)

2005 ◽  
Vol 117 (6) ◽  
pp. 3377-3380 ◽  
Author(s):  
Ben S. Cazzolato ◽  
Dick Petersen ◽  
Carl Q. Howard ◽  
Anthony C. Zander
Keyword(s):  
Energy Density ◽  
Active Control ◽  
Cautionary Note ◽  
One Dimensional
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