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Analiza wpływu niepewnych parametrów paliwa oraz grubości ścianki komory spalania na bezpieczeństwo użytkowania broni typu spud gun

Popczyk O.

Modelowanie Inżynierskie

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2016

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T. 28, nr 59

63--68

PL

Celem artykułu jest ocena bezpieczeństwa korzystania z wyrzutni na ziemniaki (ang. spud gun), która jest tanią i łatwą w budowie bronią palną. Analiza dotyczy wpływu niepewnych parametrów spalanego paliwa oraz grubości ścianki komory spalania na stan wytężenia komory spalania, który w niniejszym opracowaniu traktowany będzie jako wskaźnik bezpieczeństwa.

EN

The aim of the article is to assess the risk of using the spud gun, which is a cheap and easy firearm to build. The analysis concerns the impact of the burned fuel uncertain parameters and thickness of the wall on the stress state of the combustion chamber which will be treated as an index of safety.

2

Three-dimensional computer model of explosive forming of projectiles

Jach K., Owsik J., Świerczyński R.

Journal of Technical Physics

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2007

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Vol. 48, no 2

77-94

EN

The paper presents a new three-dimensional variant of free particles method, used for modelling of explosive formation of projectiles and exemplary results of computer simulations. Physical model is based on gas-dynamics equations (interaction of detonation products with the charge elements) and mechanics of solids (deformation and driving of metal liner and housing). The equations of the problem were solved numerically using the free particles method together with the so-called markers method, allowing for modelling boundary conditions at the contacts of media having various physical properties and any complex shapes. Significant virtue of the markers method was shown, i.e., the possibility of full automation of a calculation process, even for very complex and dynamically changing boundary conditions, e.g., during projectiles fragmentation. Many test solutions have been obtained and analysed, having in view the influence of three-dimensional effects on projectiles fragmentation and rotation. These aspects of explosive forming of projectiles were indicated which can be investigated using only 3D codes, e.g., errors and inaccuracies of metal liners manufacturing, forming of projectile fins, etc.

3

The closed form solution of the Darboux boundary value problem for backward driving of solids by the high explosive

Włodarczyk E.

Journal of Technical Physics

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2001

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Vol. 42, no 1

5-21

EN

The closed form solution of the Darboux boundary value problem, which occurs at the backward driving solids by the condensed explosive, was obtained in this paper. The constructed solution may be used, among other cases, for estimating the explosively driven elements velocity of the casing and liner of the wedge hollow charge. The solution may be applied for evaluation of the explosive active part in the wedge shaped charge, too. These problems will be considered in the next paper.

4

Effectiveness of the cylindrical hollow charge

Włodarczyk E.

Journal of Technical Physics

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2001

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Vol. 42, no 2

181-191

EN

The influence of the cavity shape of the cylindrical cumulative charge on its effectiveness in destruction activity has been analysed in this paper. It is proved that the value of the efficiency coefficient [eta] of the cylindrical hollow charge is determined, among other things, by the dimensions and the shape of the cavity. The values of the efficiency coefficient, for real hollow charges, are contained within the interval 1/9 < eta < 1/5. The maximum active mass of tile cylindrical hollow charge is described by the formula: m[a] = pi[r^3_0]rho[e]/3, where r[0] is the radius of the cylindrical hollow charge, and rho[e] denotes the density of an explosive. //\@eng\

5

Application of a cylinder test for determining energetic characteristics of explosives

Trzciński W.

Journal of Technical Physics

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2001

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Vol. 42, no 2

165-179

EN

In the work expressions for an expansion work and detonation energy of condensed explosives are derived from a quasistatic cycle for detonation. New semiempirical methods of determination of the acceleration ability of detonation products and the detonation energy are proposed. The basis of the methods is a so-called cylinder test. The procedures of applying the cylinder test data for determining the acceleration ability (so-called Gurney energy) and for estimation of the detonation energy are described. The method proposed for evaluation of the detonation energy is verified by using the cylinder test data given in literature for 17 explosives.

6

Active mass of high explosive in the wedge-shaped charge

Włodarczyk E.

Journal of Technical Physics

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2001

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Vol. 42, no 2

149-164

EN

The algebraic formulae, determining the active mass of the high explosive (HE) in the wedge-shaped charge warhead have been derived in the paper. Influences of the casing and liner inertia of the wedge cumulative warhead as well as of the liner shape on the active mass of the HE have been analysed. The presented simple formulae may be used by the engineers designing the shaped charges.

7

Thebackward launching of solids by products of detonation

Włodarczyk E.

Journal of Technical Physics

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2000

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Vol. 41, no 2

101-119

EN

The problem of the initial phase of backward launching of the concentrated masses M[sub 1] and M[sub 2] by the compressed products of detonation, was solved in a closed form. It was found that the application of the Gurney formulae to estimate the initial velocity of the explosively driven elements of the shaped charge liner is burdened with a relatively large error. It results from the linear approximation of the flow velocity of the detonation products versus the Lagrangian coordinate (r). This approximation can be used when M[sub 1] = M[sub 2] > m, where m is the explosive mass. This condition in the shaped charge ammunition (HEAT), especially in warheads with a heavy casing and thin liner, is not satisfied. Besides, it was shown that the flow velocity of the detonation products changes linearly versus the Eulerian coordinate (x). The constructed solution can be used in the description of the process of shaped charge jet formation.

8

The intensity of a shock wave created by decomposition of an arbitrary discontinuity

Włodarczyk E.

Journal of Technical Physics

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2000

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Vol. 41, no 1

3-17

EN

It was shown that the intensity of a shock wave created by a decomposition of a discontinuity in configuration A is strictly limited even for extremely high initial pressure in one of two gases being in contact. Furthermore, it was found that extreme parameters of the shock wave are linearly dependent on a Riemann invariant. The problem has obtained no attention as yet. Researchers and engineers dealing with internal ballistics, shock tubes and the theory of shock and detonation waves propagation in mixtures of gases may be able to apply the results of the present paper.

9

On the shape of the annular detonation wave front

Włodarczyk E.

Journal of Technical Physics

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2000

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Vol. 41, no 1

19-30

EN

The approximate shape was determined analytically of the surface of the spatially two-dimensional detonation wave front, cycle-initiated on the external surface of a cylindrical explosive charge. The results can be applied, among other things, in computer simulation of cumulation processes.

10

Effectiveness of high explosives in shaped charges

Włodarczyk E.

Journal of Technical Physics

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2000

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Vol. 41, no 3

189-199

EN

The formula which defines the effectiveness of high explosives (HE) in shaped charges is derived. Fundamental characteristics of the HE are the following: density rho[sub e], velocity of detonation D[sub J] and effective isentropic exponent of products of detonation (PD) gamma, as well as the quantities describing the liner, i.e. thickness of its wall g, and density of its material rho[sub l]. These parameters determine the value of velocity v[sub o] of the explosively driven liner elements of shaped charge. The results of calculations show that the most effective HE used in shaped charges are: LX-09 (LX-14) and HMX + Inert. This conclusion agrees with the experimentally obtained data [1-3, 9, 21, 22, 23].

11

Brisance of the high explosives

Włodarczyk E.

Journal of Technical Physics

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2000

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Vol. 41, no 4

343-359

EN

The essential survey of the literature data, concerning the brisance of high explosives (HE) has been made in this paper. It is confirmed that the quantitative criteria of the theoretical estimate of the HE brisance proposed in the scientific literature are based on several assumptions, which are contradictory to the real course of the explosion phenomenon, and therefore they are erroneous. These criteria must not be applicated in the engineering practice. The reflection process of the detonation wave from th inertial rigid partition was used in order to derive the new formula describing the relative brisance of the HE. Moreover, the brisance of numerous commercial explosives and the military ones has been analysed too. The results, presented in this paper, are confirmed by experimentally gained data.