Launch Dynamic Simulation of a Compressed-Air Launcher for Fire Suppression
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This paper focuses on improving fire suppression performance through the use of compressed-air launching technology. A launch dynamics calculation model of a compressed-air launcher is presented, developed using VC++ programming, to simulate the acceleration process of a fire-extinguishing bomb in a barrel. By analyzing the influences of various structural and initial parameters on interior ballistics variations, the effectiveness of the calculation model and program in accurately simulating the launching process is demonstrated. The calculation results indicate that the bore pressure follows a similar trend to that of traditional gunpowder launching. Additionally, it is found that specific structural parameters, such as nozzle diameter and gas cylinder volume, have a direct impact on interior ballistics variations. Notably, the nozzle diameter positively affects the peak pressure, muzzle velocity, gas transfer efficiency, and launch efficiency. To ensure an optimal launch effect and efficiency, the nozzle diameter should be selected to be more than half of the launcher caliber. Similarly, the gas cylinder volume positively influences the peak pressure and muzzle velocity while negatively affecting the gas transfer efficiency and launch efficiency. Furthermore, the initial pressure in the gas cylinder exhibits a positive linear relationship with both the peak pressure and muzzle velocity but a negative linear relationship with the gas transfer efficiency and launch efficiency. The loading position minimally impacts the peak pressure and muzzle velocity but slightly enhances the gas transfer efficiency and launch efficiency. Finally, it is observed that launch angles do not affect the interior ballistic process. The research findings provide valuable theoretical guidance for determining the working parameters of compressed-air accelerated fire-extinguishing bombs.Keywords:
Muzzle velocity
Muzzle
Internal ballistics
Ballistics
Compressed air
The internal ballistics of a firearm or artillery piece considers the pellet, bullet, or shell motion while it is still inside the barrel. In general, deriving the muzzle speed of a gunpowder firearm from first principles is difficult because powder combustion is fast and it very rapidly raises the temperature of gas (generated by gunpowder deflagration, or burning), which greatly complicates the analysis. A simple case is provided by air guns, for which we can make reasonable approximations that permit a derivation of muzzle speed. It is perhaps surprising that muzzle speed depends upon barrel length (artillerymen debated this dependence for centuries, until it was established experimentally and, later, theoretically1). Here we see that a simple physical analysis, accessible to high school or freshmen undergraduate physics students, not only derives realistic muzzle speed but also shows how it depends upon barrel length.
Muzzle
Internal ballistics
Gunpowder
Ballistics
Muzzle velocity
Frustum
Artillery
Deflagration
Racket
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A firing experiment of a new super-high firing rate gun with three and five serial loading projectiles is tested,and get the bore pressure data.Its classical model of interior ballistics is established and a numerical simulation is conducted.Computational results are consistent with the experimental ones.This shows that the simulation of the interior ballistic process is feasible.The effect of the variation of firing rate upon the interior ballistics characteristics and the muzzle velocity were discussed in detail,and get the regulations.The researches can be used for reference for subsequent research.
Internal ballistics
Ballistics
Muzzle
Muzzle velocity
Light-gas gun
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Abstract : Two muzzle jet flow simulators which use clean propelling gases of known properties are described. Photographs and pressure data obtained in the simulators as a jet forms behind a shock wave which has left the simulator muzzle are shown and discussed. Of particular interest is an experiment using a ruby laser as a multiple-pulse light source to obtain a sequence of several laser interferograms for a single run from which quantitative data can be obtained. It was shown that the growth of the outer shock wave obeys a power law in time; the exponent n is approximately 0.715. Scaling of the inner shock wave development is also discussed. Inner and outer shock wave motion appeared to be coupled in the quasi-steady flow regime. Spark shadow photographs of jet formation after a projectile uncorks the muzzle are also shown and discussed-- optical probing of the real environment near the muzzle of guns is virtually impossible.
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Internal ballistics
Muzzle
Muzzle velocity
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This paper establishes an internal ballistic correlation for conventional guns as a function of travel of the projectile in the barrel bore. This function has three parameters that match calculation results or experimental results. Three parameters are determined by these characteristics: maximum pressure of propellant gases, muzzle pressure of propellant gases, and muzzle velocity of the projectile. According to the ballistic correlation, the utilization coefficient of the barrel bore volume for a specific gun can be evaluated by maximum pressure and muzzle pressure.
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Muzzle velocity
Internal ballistics
Internal pressure
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An account is given of the more common experimental methods used in ballistics for the determination of the muzzle velocity of projectiles.
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Internal ballistics
Ballistics
Muzzle velocity
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A firing experiment of super-high firing rate gun with three serial loading projectiles is tested.Its classical model of interior ballistics is established and a numerical simulation is conducted.Computational results are consistent with the experimental ones.This shows that the simulation of the interior ballistic process is feasible.The effects of the firing rate on the maximum bore pressure and the muzzle velocity are analyzed.It is shown that the firing rate must be below a limit,in which the next propellant is ignited after the previous projection departs from the muzzle and the pressure decreases to a certain value.This avoids the interaction of the interior ballistics processes between different projectiles and reduces the velocity deviation.
Internal ballistics
Muzzle velocity
Muzzle
Ballistics
Ballistic limit
Light-gas gun
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The idea of the application of internal ballistics models together with external ballistics models in fire control systems encounters a problem in relating the calculated muzzle velocity value to the initial velocity value used in external ballistics calculations. The difference between these two values is caused by the action on the projectile of the propellant gases exiting from the muzzle. In this paper an attempt has been made to estimate the increase in projectile velocity outside the muzzle by the use of CFD modelling. The commercial ANSYS FLUENT code has been used together with our own ID model for the internal ballistics period. Calculations have been performed for various launching systems, from small arms to a 155 mm calibre gun. CONCLUSIONS have been drawn concerning the magnitude of the increase in projectile velocity outside the muzzle. The main conclusion is that the velocity increase is generally less than 1% and in most cases can be neglected. Language: en
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Internal ballistics
Muzzle
Ballistics
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The bombard Mons Meg, located in Edinburgh Castle, with a diameter of 19 inches (48 cm), was one of the largest calibre cannons ever built. Constructed in 1449 and presented to King James II of Scotland in 1454, Mons Meg was used in both military and ceremonial roles in Scotland until its barrel burst in 1680. This paper examines the history, internal, external and terminal ballistics of the cannon and its shot. The likely muzzle velocity was estimated by varying the propellant type and the cannon profile was investigated to identify weak spots in the design that may have led to its failure. Using the muzzle velocity calculated from the internal ballistics, simulations were performed with granite and sandstone shot for varying launch angle and ground temperature. The likely trajectory and range of the cannonballs are described. The internal and external ballistics informed the initial conditions of the terminal ballistic impact scenarios. The performance of the cannonball against both period and modern targets, in the form of a pseudo-castle wall and a monolithic concrete target, respectively, were simulated and are presented and discussed.
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Ballistics
Muzzle
Internal ballistics
Dynamite
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A method for intermediate ballistics modelling is presented. The method is used to study the effect of muzzle brakes with a passing projectile. Pressures, velocities and impulses are computed using a thermodynamic interior ballistics code (lumped parameter code) for projectile travel within the barrel. Then Computational Fluid Dynamics (CFD) simulations are used for gas and projectile travel outside the barrel. CFD simulations are performed both with and without a projectile and the results compared. Three generic muzzle brake geometries are used for simulations. Impulses computed from thermodynamic model and CFD model are combined to evaluate the gun recoil. The CFD model, with initial conditions transferred from the thermodynamic model, can further be used to analyse the influence from the muzzle break on the flow.
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Internal ballistics
Muzzle velocity
Ballistics
Projectile motion
Recoil
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Aiming at the complicated characteristics of interior ballistic process of metal storm weapon,the one-dimensional two-phase flow model was established,and the CTVD algorithm with high efficiency was also introduced for numerical simulation.The interior ballistic process of metal storm weapon under strong coupling firing,weak coupling firing,and non-coupling firing were analyzed in detail based on the calculation results,and the variation courses of breed pressure and the bullet velocity with time were also obtained.The results show that the higher the firing frequency,the higher the maximum bore pressure and the lower the muzzle velocity of projectile.Under the conditions of ignoring the coupling effect,the nearer the distance between loading position of projectile and the rear end,the greater the muzzle velocity of projectile.The maximum bore pressure is only affected by dynamic pressure and is irrelevant to loading position.
Muzzle velocity
Internal ballistics
Muzzle
Ballistics
Position (finance)
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