scholarly journals Study on Micro Recoil Mechanism of the Weapon with a Nozzle and Two Chambers Separated by a Partition

2021 ◽  
Vol 2097 (1) ◽  
pp. 012009
Author(s):  
Longxu Ma ◽  
Ming Qiu ◽  
Jie Song ◽  
Peng Si ◽  
Zhenqiang Liao
Keyword(s):  
Two Phase Flow ◽  
Phase Flow ◽  
Ballistic Performance ◽  
Two Phase ◽  
Reduction Efficiency ◽  
Conventional Weapons ◽  
Calculation Results ◽  
Physical Fields ◽  
The One ◽  
Ballistic Model

Abstract In order to improve the recoil reduction ability of the weapon without reducing the projectile velocity, the weapon with a nozzle and two chambers separated by a partition is proposed. Taking the 35 mm caliber grenade launcher as the research object, the physical model of its launching process is proposed, and the one-dimensional two-phase flow interior ballistic model is established. MacCormack difference scheme is used to calculate the coupling of multiple physical fields formed by front and rear chambers and nozzles. Compared with the calculation results obtained by using the classical interior ballistic model, the correctness of the two-phase flow interior ballistic model is verified. The effects of the charge amount in the rear chamber and the size of the air guide hole in the barrel on the internal ballistic performance of the weapon with a nozzle and two chambers separated by a partition. The calculation results show that compared with conventional weapons, the recoil impulse can be reduced with maintaining muzzle velocity, and the recoil reduction efficiency can reach 72.27%, which is of great significance for improving weapon performance.

Drag Reduction of Gas-Liquid Two-Phase Flow in Steel Pipes with Different Inclination Geometry

2012 ◽  
Vol 433-440 ◽  
pp. 463-470
Author(s):  
Lei Liu ◽  
Xin Feng Guo ◽  
Qiu Yue Guo ◽  
Hui Qing Fan ◽  
Zhu Hai Zhong
Keyword(s):  
Drag Reduction ◽  
Two Phase Flow ◽  
Vertical Section ◽  
High Energy ◽  
Phase Flow ◽  
Two Phase ◽  
Steel Pipes ◽  
Horizontal Pipes ◽  
Reduction Efficiency ◽  
Reduction Characteristics

It is significant to make researches on drag reduction in two-phase transport pipeline because two-phase flow has high energy dissipation. API X 52 steel pipe with diameter of 40mm is used in this paper to simulate pipeline with different inclination geometry including horizontal, up-inclined and vertical sections. The up-inclined section has an inclination angle of eight degree. Experiments and theoretical analysis are carried out to study the drag reduction characteristics of gas-liquid two-phase flow in these three sections. The drag reducing agents used here is polyacrylamide. It is found that two-phase drag reduction varies with pipe inclination geometry. The largest drag reduction efficiency occurs in horizontal pipes and which is up to seventy percent. Drag reduction efficiency in up-inclined section is up to sixty percent. Drag reduction in vertical section is the lowest and which can be up to about thirty percent. A mechanistic drag reduction model is proposed to predict drag reduction in gas-liquid two-phase flow. The results predicted are in good agreement with the experiment data.

Experimental Study and Numerical Simulation of Propellant Ignition and Combustion for Cased Telescoped Ammunition in Chamber

2010 ◽  
Vol 77 (5) ◽  
Author(s):  
Xin Lu ◽  
Yanhuang Zhou ◽  
Yonggang Yu
Keyword(s):  
High Speed ◽  
Two Phase Flow ◽  
Video Recording ◽  
Phase Flow ◽  
Ballistic Performance ◽  
Projectile Velocity ◽  
Two Phase ◽  
Control Tube ◽  
Improved Performance ◽  
Ignition And Combustion

Cased telescoped ammunition (CTA) is a kind of charge structure with projectile embedded in the cartridge case. The advantages of CTA, compared with concepts using conventional ammunition, are: (1) reduced charge/ammunition volume, (2) improved performance, and (3) enhanced power and survivabillity of armament. The projectile is placed in the control tube of the cartridge before shooting. After the primer is struck, propellant product gases, generated by the igniter charge burning in the central igniter tube, drive the projectile to move forward along the control tube, and then causing the main propellants around the igniter tube and control tube to burn. Therefore, in the process of interior ballistics, there is a motion of the projectile in the control tube before the projectile engraves the rifles, in contrast with the traditional ammunition. The consistency of this motion has an important influence on the stability of CTA interior ballistic performance. The experiments on the ignition and combustion of propellants and motion of projectile in the control tube are carried out using a high-speed video recording system in this study. The projectile velocity at the entrance of the rifle is obtained from the recorded images. A two-phase flow model of CTA is also established and simulated by using the two-phase flow method and computational fluid dynamics technology. The calculated projectile velocity is in good agreement with the experimental data. The numerical results show that the developed mathematical model gives the correct trend and can provide useful calculated parameters for the structural design of CTA components.

Experimental Investigation of Pressure Drop in One Phase Flow, Particle-Liquid Two-Phase Flow, and Porous Media Consisting of the Same Particle Size

2009 ◽  
Vol 283-286 ◽  
pp. 599-603
Author(s):  
Hikmet Ş. Aybar ◽  
Mohsen Sharifpur ◽  
Roozbeh Vaziri
Keyword(s):  
Particle Size ◽  
Porous Media ◽  
Pressure Gradient ◽  
Two Phase Flow ◽  
Water Pressure ◽  
Spherical Particles ◽  
Phase Flow ◽  
Two Phase ◽  
The One ◽  
Flow Particle

Many researches have performed some studies about pressure gradient in the one phase flow, particle-liquid two-phase flow and porous media. However, there is no any report about interaction among them. In this study, this interaction idea is developed by using the same particle size for particle-liquid two-phase flow and porous media. For the experimental study, an apparatus is designed, and at the first step one phase water pressure gradient is investigated, next in the further steps, little by little spherical particles are added to the cycle till accumulation of the particles did not allow any movement to the particles (i.e. porous media occur), and after that well pack porous media is investigated. The results confirm the relation between pressure gradient over mass flow rate in the one phase flow, particle-liquid two-phase flow and porous media obeys as a parabolic curve.

Motion stability of a periodic system of bubbles in a liquid

2001 ◽  
Vol 438 ◽  
pp. 247-275 ◽  
Author(s):  
OLEG V. VOINOV
Keyword(s):  
Periodic Structure ◽  
Potential Flow ◽  
Two Phase Flow ◽  
Dimensional Structure ◽  
Bubbly Liquid ◽  
Phase Flow ◽  
Two Phase ◽  
One Dimensional ◽  
Stability And Instability ◽  
The One

Wave-like motion in a periodic structure of bubbles that steadily moves through ideal incompressible liquid is considered. The wavelength is microscopically short. Some general local properties containing general information about two-phase flow are found. The dynamics of small-amplitude disturbances is studied in linear systems (called trains) and in spatial structures (such as a cubic lattice). The behaviour of one-dimensional waves in various structures is shown to differ widely: one-dimensional waves in the train do not magnify, whereas in the three-dimensional structure there may be stability and instability of one-dimensional waves. In the continuum limit the one-dimensional instability is demonstrated not to be related to the mean parameters of two-phase flow. The long-wave dynamics is shown to depend significantly on the relative velocity vector orientation in the lattice, but orientation is not included in the usual equations for the two-phase continuum. One result of this study is the relation between the short-wave-type instability of the periodic structure, on the one hand, and the instability of one-dimensional flow of inviscid bubbly liquid discovered by van Wijngaarden on the other. Long microscopic waves are analysed to determine the coefficients of one-dimensional equations for a two-phase continuum model. The velocity orientation at which the coefficients of the traditional one-dimensional model are obtained is found. Short waves in a stationary structure are studied by using the system of equations based on the equation of motion of a small sphere in a general potential flow. A refined equation for the force applied on a sphere in a non-uniform potential flow is derived.

Two Phase Flow Modeling of the Interior Ballistics for a Naval Medium Caliber Gun with Guided Projectile

2013 ◽  
Vol 465-466 ◽  
pp. 531-535
Author(s):  
Hazem Elsadek ◽  
Xiao Bing Zhang ◽  
Mahmod M. Rashad ◽  
Cheng Cheny
Keyword(s):  
Fluid Dynamics ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Flow Modeling ◽  
Governing Equations ◽  
Ballistic Performance ◽  
Two Phase ◽  
Interior Ballistics ◽  
Simulation Results ◽  
Good Agreement

This paper discusses the two phase (gas/Particles) flow effect of interior ballistic performance in a 76 mm naval medium caliber gun with guided projectile, using granular seven-perforated propellant. The theoretical and numerical simulation of the two phase flow in the interior ballistic cycle is carried out by using MacCromack technique depending on the governing equations of the two phase flow. This simulation is considered to be helpful for the prediction of the interior ballistic parameters which are required for endurance of guided projectile. A good agreement between the simulation results compared to the experimental results is fulfilled. Keywords: Guided projectile, two phase flow modeling, Interior ballistic, Computational fluid dynamics.

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