Numerical Study on Properties of Interior Ballistics According to Solid Propellant Position in Chamber

2011 ◽  
Author(s):  
Jin-Sung Jang ◽  
Hyung-Gun Sung ◽  
Seung-Young Yoo ◽  
Tae-Seong Roh ◽  
Dong-Whan Choi
Keyword(s):  
Solid Propellant ◽  
Moving Boundary ◽  
Two Phase Flow ◽  
Numerical Study ◽  
Simple Algorithm ◽  
High Energy ◽  
Numerical Code ◽  
Phase Flow ◽  
Two Phase ◽  
Interior Ballistics

Analysis of the interior ballistics is essential for the development of gun or propellant configurations. The granular solid propellants with high energy and fast burning rate produce a large thrust in extremely short time intervals. For the study of these, therefore, it is necessary of a numerical code for the two-phase flow of the interior ballistics. Recently, an interior ballistics code (IBcode) for the two-phase flow using the Eulerian-Lagrangian approach has been developed. The SIMPLE algorithm and the SMART scheme have been used for the IBcode. The ghost-cell extrapolation method has been used for the moving boundary with the projectile movement. In this study, a performance of the interior ballistics according to the position of the solid propellant in the chamber has been investigated using the IBcode. In previous researches, propellants had been evenly distributed in the chamber. In this study, however, three cases of the existence of empty space in the chamber at which the propellants are not evenly distributed have been considered; Propellants are located in the region near the base, propellants in the region near the breech, and propellants in the center of the chamber, respectively. The 7-perforated configuration of the solid propellant has been used in this research. The results have shown the performance variations of the interior ballistics according to solid propellant position in the chamber. The cases of the propellants located in the region near the base and breech have shown that the value of the negative differential pressure and the difference between the breech pressure and the base pressure are much higher than those of the propellants located in the center of the chamber. The case of the propellants in the center of the chamber is, therefore, more profitable to improve the performance of the interior ballistics.

Two-Phase Flow Interior Ballistics Model of Naval Large Caliber Guided Projectile Gun System

2013 ◽  
Vol 465-466 ◽  
pp. 592-596
Author(s):  
Mahmoud M. Rashad ◽  
Xiao Bing Zhang ◽  
Hazem El Sadek ◽  
Cheng Cheng
Keyword(s):  
Flow Model ◽  
Moving Boundary ◽  
Two Phase Flow ◽  
Control Volume ◽  
Numerical Code ◽  
System Of Equations ◽  
Phase Flow ◽  
Computational Domain ◽  
Two Phase ◽  
Interior Ballistics

The two-phase flow mathematical model for the solid granular propellant and its products of combustion inside large caliber naval gun guided projectile system (NGGPS) during interior ballistic cycle is presented. The model includes the governing equations of mass, momentum and energy for both phases as well as the constitutive laws. The discharged combustion products from the igniter vent-holes into the chamber are acquired by incorporation in the model the two-phase flow model of the bayonet igniter. The system of equations of the two-phase flow model is solved using the second order accurate Maccromacks technique. A one dimensional model introduced by G.A. Sod (shock tube) is utilized to test the ability of Maccromacks algorithm in solving the initial boundary value problem (IBVP) for the system of equations with shock wave behavior. The numerical method is verified by using an exact solution of a test problem. The moving control volume conservation method (MCVC) is used to handle the moving boundary as well as a self-adapting method was used to expand the computational domain in order to follow the movement of the projectile down the gun bore. The numerical results are validated with experimental data. The interior ballistics performance of a 130 mm naval guided projectile gun system is closely predicted using the presented two-phase flow model and the numerical code.

Numerical study on two-phase flow through fractured porous media

2011 ◽  
Vol 54 (9) ◽  
pp. 2412-2420 ◽  
Author(s):  
ZhaoQin Huang ◽  
Jun Yao ◽  
YueYing Wang ◽  
Ke Tao
Keyword(s):  
Porous Media ◽  
Two Phase Flow ◽  
Numerical Study ◽  
Fractured Porous Media ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Through

scholarly journals Numerical Study on the Gas-Water Two-Phase Flow in the Self-Priming Process of Self-Priming Centrifugal Pump

Processes ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 330 ◽  
Author(s):  
Chuan Wang ◽  
Bo Hu ◽  
Yong Zhu ◽  
Xiuli Wang ◽  
Can Luo ◽  
...  
Keyword(s):  
Centrifugal Pump ◽  
Two Phase Flow ◽  
Numerical Study ◽  
The Self ◽  
Main Stage ◽  
Phase Flow ◽  
Urban Greening ◽  
Two Phase ◽  
Ansys Cfx ◽  
Priming Process

A self-priming centrifugal pump can be used in various areas such as agricultural irrigation, urban greening, and building water-supply. In order to simulate the gas-water two-phase flow in the self-priming process of a self-priming centrifugal pump, the unsteady numerical calculation of a typical self-priming centrifugal pump was performed using the ANSYS Computational Fluid X (ANSYS CFX) software. It was found that the whole self-priming process of a self-priming pump can be divided into three stages: the initial self-priming stage, the middle self-priming stage, and the final self-priming stage. Moreover, the self-priming time of the initial and final self-priming stages accounts for a small percentage of the whole self-priming process, while the middle self-priming stage is the main stage in the self-priming process and further determines the length of the self-priming time.

scholarly journals Numerical Study of Bubble Rising and Coalescence Characteristics under Flow Pulsation Based on Particle Method

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Ronghua Chen ◽  
Minghao Zhang ◽  
Kailun Guo ◽  
Dawei Zhao ◽  
Wenxi Tian ◽  
...  
Keyword(s):  
Flow Rate ◽  
Two Phase Flow ◽  
Flow Instability ◽  
Numerical Study ◽  
Phase Flow ◽  
Flow Pulsation ◽  
Two Phase ◽  
Inlet Flow ◽  
Inlet Flow Rate ◽  
Bubble Rising

Two-phase flow instability may occur in nuclear reactor systems, which is often accompanied by periodic fluctuation in fluid flow rate. In this study, bubble rising and coalescence characteristics under inlet flow pulsation condition are analyzed based on the MPS-MAFL method. To begin with, the single bubble rising behavior under flow pulsation condition was simulated. The simulation results show that the bubble shape and rising velocity fluctuate periodically as same as the inlet flow rate. Additionally, the bubble pairs’ coalescence behavior under flow pulsation condition was simulated and compared with static condition results. It is found that the coalescence time of bubble pairs slightly increased under the pulsation condition, and then the bubbles will continue to pulsate with almost the same period as the inlet flow rate after coalescence. In view of these facts, this study could offer theory support and method basis to a better understanding of the two-phase flow configuration under flow pulsation condition.

Gas–solid two-phase flow in an underground mine with an optimized air-curtain system: A numerical study

2020 ◽  
Vol 140 ◽  
pp. 137-150 ◽  
Author(s):  
Changgeng Gui ◽  
Fan Geng ◽  
Junhua Tang ◽  
Hongwei Niu ◽  
Fubao Zhou ◽  
...  
Keyword(s):  
Two Phase Flow ◽  
Numerical Study ◽  
Underground Mine ◽  
Phase Flow ◽  
Two Phase ◽  
Air Curtain ◽  
System A

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.

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