Quantitative Effects of Projectile-Launch Tube Wall Friction on Ballistic Range Operation

AIAA Journal ◽  
2000 ◽  
Vol 38 (9) ◽  
pp. 1709-1715 ◽  
Author(s):  
Akihiro Sasoh ◽  
Shinji Ohba ◽  
Kazuyoshi Takayama
Keyword(s):  
Tube Wall ◽  
Wall Friction ◽  
Ballistic Range ◽  
Launch Tube

Quantitative effects of projectile-launch tube wall friction on ballistic tange operation

AIAA Journal ◽  
2000 ◽  
Vol 38 ◽  
pp. 1709-1715
Author(s):  
Akihiro Sasoh ◽  
Shinji Ohba ◽  
Kazuyoshi Takayama
Keyword(s):  
Tube Wall ◽  
Wall Friction ◽  
Launch Tube

Numerical Analysis of Projectile-Launch Tube Wall Friction Effects on Projectile Acceleration in Single-Stage Gun

2007 ◽  
Vol 566 ◽  
pp. 71-76
Author(s):  
Hiroaki Miura ◽  
Akiko Matsuo
Keyword(s):  
Friction Force ◽  
Tube Wall ◽  
Single Stage ◽  
Wall Friction ◽  
Chamber Pressure ◽  
Two Phase ◽  
One Dimensional ◽  
Interior Ballistics ◽  
The Impact ◽  
Launch Tube

The effects of the friction between the projectile and launch-tube wall in a single-stage gun are examined by the interior ballistics simulations. The solid/gas two-phase flow code for two-dimensional axisymmetric calculation is used in the simulations. In this study, one-dimensional quasi-steady-state elastic relations are applied to the projectile in the estimation of the friction force. The calculation method is validated by the comparison of the simulated results with the experimental data such as the histories of the breech pressure and the projectile acceleration. The simulated results reveal that the impact of the shock waves to the base increases the friction force acting on the projectile. The large friction force in the tight fit case decelerates the projectile, consequently intensifying the chamber pressure. The muzzle velocity decreases with the increase of the projectile diameter, and this appears strongly in the low chamber pressure case.

Observation of the Sulphur Atoms in Cu2S Using HREM

1990 ◽  
Vol 48 (1) ◽  
pp. 38-39
Author(s):  
Y.D. Yu ◽  
R. Guan ◽  
K.H. Kuo ◽  
H. Hashimoto
Keyword(s):  
Electron Diffraction ◽  
Tube Wall ◽  
Present Report ◽  
Dynamic Effect ◽  
Glass Tube ◽  
Fluorite Structure ◽  
Point Of View ◽  
Electron Diffraction Analysis ◽  
Sulphur Atom ◽  
Copper Thin Film

We have indicated that the lighter atoms such as oxygen in Cu2O can be observed at the specimen with optimal thicknesses based on the dynamic effect of electron diffraction(1). This rule in principle should hold good for the imaging of other lighter atoms such as sulphur atom in Cu2S. However, this point of view needs further experimentally confirm because up to now only oxygen atoms have been observed in Cu2O and a series of new suboxides of copper and nickel (2). In addition, the sulphur atom is much heavier than oxygen one though is still lighter than copper atom. In the present report we provide such a confirmation.The crystallites of Cu2S shown in Fig.l were obtained by sulfurizing at 300°C of the copper thin film which was sealed in a glass tube with mg sulphur left on the tube wall in a vacuum of about 10-2 Pa. The energy dispersive spectrocscopy analysis indicated that they are the sulfides and the electron diffraction analysis indicated they have anti-fluorite structure.

Measurement of Tube Wall Ablation in Hypervelocity Flows

2014 ◽  
Author(s):  
Myles Hildebrand ◽  
Justin Huneault ◽  
Jason Loiseau ◽  
Andrew J. Higgins
Keyword(s):  
Tube Wall ◽  
Hypervelocity Flows

Fabrication and charge storage capacitance of PPY/TiO2/PPY jacket nanotube array

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Yibing Xie
Keyword(s):  
Density Of States ◽  
Electrode Material ◽  
Acidic Solution ◽  
Tube Wall ◽  
Internal Surface ◽  
Experimental Result ◽  
Charge Storage ◽  
Current Response ◽  
Supercapacitor Electrode ◽  
Nanotube Array

AbstractA PPY/TiO2/PPY jacket nanotube array was fabricated by coating PPY layer on the external and internal surface of a tube wall-separated TiO2 nanotube array. It shows coaxial triple-walled nanotube structure with two PPY nanotube layers sandwiching one TiO2 nanotube layer. PPY/TiO2/PPY reveals much higher current response than TiO2. The theoretical calculation indicates PPY/TiO2/PPY reveals higher density of states and lower band gap, accordingly presenting higher conductivity and electroactivity, which is consistent with the experimental result of a higher current response. The electroactivity is highly enhanced in H2SO4 rather than Na2SO4 electrolyte due to feasible pronation process of PPY in an acidic solution. PPY/TiO2/PPY could conduct the redox reaction in H2SO4 electrolyte which involves the reversible protonation/deprotonation and HSO4− doping/dedoping process and accordingly contributes to Faradaic pseudocapacitance. The specific capacitance is highly enhanced from 1.7 mF cm−2 of TiO2 to 123.4 mF cm−2 of PPY/TiO2/PPY at 0.1 mA cm−2 in H2SO4 electrolyte. The capacitance also declines from 123.4 to 31.7 mF cm−2 when the current density increases from 0.1 to 1 mA cm−2, presenting the rate capacitance retention of 26.7% due to the semiconductivity of TiO2. A PPY/TiO2/PPY jacket nanotube with high charge storage capacitance is regarded as a promising supercapacitor electrode material.

scholarly journals Towards Manufacturing of Ultrafine-Laminated Structures in Metallic Tubes by Accumulative Extrusion Bonding

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 389
Author(s):  
Matthew R. Standley ◽  
Marko Knezevic
Keyword(s):  
Solid State ◽  
Wall Thickness ◽  
Complex Geometry ◽  
Tube Wall ◽  
Film Theory ◽  
Radial Strain ◽  
Surface Preparation ◽  
Grain Structure ◽  
Outer Diameter ◽  
Laminated Structures

A severe plastic deformation process, termed accumulative extrusion bonding (AEB), is conceived to steady-state bond metals in the form of multilayered tubes. It is shown that AEB can facilitate bonding of metals in their solid-state, like the process of accumulative roll bonding (ARB). The AEB steps involve iterative extrusion, cutting, expanding, restacking, and annealing. As the process is iterated, the laminated structure layer thicknesses decrease within the tube wall, while the tube wall thickness and outer diameter remain constant. Multilayered bimetallic tubes with approximately 2 mm wall thickness and 25.25 mm outer diameter of copper-aluminum are produced at 52% radial strain per extrusion pass to contain eight layers. Furthermore, tubes of copper-copper are produced at 52% and 68% strain to contain two layers. The amount of bonding at the metal-to-metal interfaces and grain structure are measured using optical microscopy. After detailed examination, only the copper-copper bimetal deformed to 68% strain is found bonded. The yield strength of the copper-copper tube extruded at 68% improves from 83 MPa to 481 MPa; a 480% increase. Surface preparation, as described by the thin film theory, and the amount of deformation imposed per extrusion pass are identified and discussed as key contributors to enact successful metal-to-metal bonding at the interface. Unlike in ARB, bonding in AEB does not occur at ~50% strain revealing the significant role of more complex geometry of tubes relative to sheets in solid-state bonding.

Application of generalized Fourier heat conduction law on MHD viscoinelastic fluid flow over stretching surface

2019 ◽  
Vol 30 (6) ◽  
pp. 3481-3496 ◽  
Author(s):  
Arif Hussain ◽  
Muhammad Yousaf Malik ◽  
Mair Khan ◽  
Taimoor Salahuddin
Keyword(s):  
Heat Flux ◽  
Fluid Flow ◽  
Friction Factor ◽  
Numerical Technique ◽  
Wall Heat Flux ◽  
Constitutive Law ◽  
Wall Friction ◽  
Theoretical Physics ◽  
Stretching Surface ◽  
Content Type

Purpose The purpose of current flow configuration is to spotlights the thermophysical aspects of magnetohydrodynamics (MHD) viscoinelastic fluid flow over a stretching surface. Design/methodology/approach The fluid momentum problem is mathematically formulated by using the Prandtl–Eyring constitutive law. Also, the non-Fourier heat flux model is considered to disclose the heat transfer characteristics. The governing problem contains the nonlinear partial differential equations with appropriate boundary conditions. To facilitate the computation process, the governing problem is transmuted into dimensionless form via appropriate group of scaling transforms. The numerical technique shooting method is used to solve dimensionless boundary value problem. Findings The expressions for dimensionless velocity and temperature are found and investigated under different parametric conditions. The important features of fluid flow near the wall, i.e. wall friction factor and wall heat flux, are deliberated by altering the pertinent parameters. The impacts of governing parameters are highlighted in graphical as well as tabular manner against focused physical quantities (velocity, temperature, wall friction factor and wall heat flux). A comparison is presented to justify the computed results, it can be noticed that present results have quite resemblance with previous literature which led to confidence on the present computations. Originality/value The computed results are quite useful for researchers working in theoretical physics. Additionally, computed results are very useful in industry and daily-use processes.

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