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Series chamber is a new technology on the basis of the mature technology of solid propellant. It can improve the propeller' s kinetic energy through rebuilding the existed guns. It is important to the weapons' performance improvement. The two phase flow model of the interior ballistics process of 140 mm series chamber gun is established and simulated by MacCormack scheme. In addition, the completed programming has been used to analyze the influence of main-secondary powder proportion, ignition delay of secondary power and piston mass on interior ballistics performance. The result shows that the new technology can improve propeller's velocity while not adding chamber's pressure. [ABSTRACT FROM AUTHOR]

Considering that the length of the tubular charge for the large caliber high speed Davis gun is long, the traditional pseudo-fluid hypothesis in two-phase flow model may cause errors. In order to solve this problem, Eulerian coordinate system is used to settle the gas field, and the Lagrangian coordinate system is used to settle the solid field. It is assumed that the tubular charge clusters are linearly configured along radial direction, these clusters move along axial direction，and gas moves along radial and axial directions. Based on this assumption, a two-dimensional interior ballistics model is established for a 480 mm Davis gun with tubular modular charge. Then through the comparison of the simulated and experimental results, the proposed model is verified to be effective. The distribution of gas pressure along two directions and the movement rules of tubular charge clusters along axial direction were obtained by further analysis of the simulated results. [ABSTRACT FROM AUTHOR]

Based on the principle of two-stage light gas gun, an interior ballistics numerical analysis program was developed to analyze the performance and operation of two-stage light gas gun. The included numerical models were: a quasi-one-dimensional, two-phase hydrodynamics model to simulate the combustion of solid propellant in the gunpowder chamber and pump tube, an unsteady, quasi-one-dimensional, compressible flow model to analyze the flow of hydrogen gas between the piston and projectile, a one-dimensional, ideal-viscoplastic, extrusion model to simulate the motion of piston in high pressure section, and a friction model combined the classical law of frication to describe the motions of piston and sabot in the pump and launch tubes. The friction and heat transfer to the tube wall for gases and solid media are also modeled. The governing equations of gas flow were solved by CFD methods, which have second-order accurate in space and time. The interior ballistics characteristics of two-stage light gas guns of CARDC were analyzed under the typical test operating conditions, and the numerical projectile velocities were agreed well with that of test results. With the help of this program, the motion process of piston and the history of projectile acceleration loads could be obtained. The proposed method provides a way to optimize the operating conditions and improve the performance of two-stage light gas gun. [ABSTRACT FROM AUTHOR]

An improved two-phase flow model is established to simulate the interior ballistic characteristics of modular propellant charge. In this model, the constraint of the walls of modules on gas flow is taken into account. The rupture rule of combustible case and the flame spreading between different modules are also considered in the improved model. This model turned out to be reliable by comparing the numerical results with the experimental data. It can be used to predict the development of pressure waves and to diagnose the interior ballistic performance of modular propellant charge systems. The simulation results show that the flame spreads slower because the gas is constrained by the bottom walls of the center-tube. The combustible cases are ruptured in sequence, the time when the combustible cases begin to rupture until all the cases rupture is affected by the strength of the modular case and the ignition core. [ABSTRACT FROM AUTHOR]

The two-phase flow mathematic models are developed for gas generator with central igniter tube. The one-dimensional two-phase model is used for the ignition of central igniter tube, and the two-dimensional two-phase model is used for the energy release of tubular gas generator. The coupling function of two tubes is established through exchange between gas and solid. The interior ballistic simulation software is programmed by Mac Cormack two-step scheme and is used to calculate the gas generator. The calculated results well accord with the test results, which proves that the model is right and provides important theory foundation to structure design and optimization on gas generator with central igniter tube. Meanwhile, the energy releasing course is analyzed based on the simulation results. The result shows that the uniform ignition condition is the precondition of gas generator releasing energy steadily. The ignition energy released uniformly could ensure the reliable burning of powders in gas generator and the release of controlled energy. [ABSTRACT FROM AUTHOR]

To simplify the complexity of moving boundary treatment in the two-phase flow numerical simulation and improve the computational accuracy of moving boundary treatment, a two-dimensional twophase flow model based on ALE method is established. The governing equations are discretized with the TVD-type MUSCL scheme to obtain a second order accuracy in finite volume form. A two-step and fourthorder Runge-Kutta method is used to solve the source terms. The dynamic mesh update method and numerical method are verified by a standard test with the exact solution. The numerical application on a large caliber guided projectile shows the complete development and the two-phase flow characteristics of the interior ballistic process. The calculated results are in good agreement with the experimental results. The effects of different ignition conditions on interior ballistic performance are investigated. The study lays a theoretical foundation for deep optimization of the interior ballistic performance and firing safety. [ABSTRACT FROM AUTHOR]

A three-dimensional two-phase flow model based on arbitrary Lagrange-Euler method is established to improve the computational accuracy and cost of three-dimensional simulation for interior ballistic in guns. The three-dimensional governing equations are discretized with the MUSCL scheme. The fourth-order Runge-Kutta method is used to solve the time orientation. The numerical method is coded and compiled in the MPI parallel environment. The numerical simulation shows the detailed three-dimensional development of the two-phase flow behavior. The calculated results are in good agreement with the results in Ref.［20］. The effects of different igniter lengths and diameters on interior ballistic performance are analyzed. Parallel numerical studies show that the parallel efficiency can be reduced by about 50% using interior ballistic three-dimensional calculation of 24 processes. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Ballistics / Dandao Xuebao is the property of Journal of Ballistics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Ballistics / Dandao Xuebao is the property of Journal of Ballistics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Ballistics / Dandao Xuebao is the property of Journal of Ballistics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Ballistics / Dandao Xuebao is the property of Journal of Ballistics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)