Research

13 pages, 3153 KiB

Open AccessArticle

Shock Initiation and Propagation of Detonation in ANFO

by Vječislav Bohanek, Barbara Štimac Tumara, Chan Hay Yee Serene and Muhamed Sućeska

Energies 2023, 16(4), 1744; https://0-doi-org.brum.beds.ac.uk/10.3390/en16041744 - 09 Feb 2023

Cited by 3 | Viewed by 1990

The ammonium nitrate (AN) and fuel oil (FO) mixture known as ANFO is a typical representative of non-ideal explosives. In contrast to ideal explosives, the detonation behavior of ANFO exhibits a strong dependence on charge diameter, existence, and properties of confinement, with a [...] Read more.

The ammonium nitrate (AN) and fuel oil (FO) mixture known as ANFO is a typical representative of non-ideal explosives. In contrast to ideal explosives, the detonation behavior of ANFO exhibits a strong dependence on charge diameter, existence, and properties of confinement, with a large failure diameter and long distance required to establish steady-state detonation. In this study shock initiation and propagation of detonation in ANFO were studied experimentally by determining the detonation velocity at different distances from the initiation point, as well as by numerical modeling using AUTODYN hydrodynamics code and a Wood–Kirkwood detonation model incorporated into EXPLO5 thermochemical code. The run-to-steady-state detonation velocity distance was determined as a function of charge diameter, booster charge mass, and confinement. It was demonstrated that a Lee–Tarver ignition and growth reactive flow model with properly calibrated rate constants was capable of correctly ascertaining experimentally observed shock initiation behavior and propagation of detonation in ANFO, as well as the effects of charge diameter, booster mass, and confinement. Full article

(This article belongs to the Special Issue Energetic Materials: Ignition and Combustion)

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11 pages, 990 KiB

Open AccessFeature PaperArticle

Insight into the Thermodynamic Properties of Promising Energetic HNTO·AN Co-Crystal: Heat Capacity, Combustion Energy, and Formation Enthalpy

by Amir Abdelaziz, Ahmed Fouzi Tarchoun, Hani Boukeciat and Djalal Trache

Energies 2022, 15(18), 6722; https://0-doi-org.brum.beds.ac.uk/10.3390/en15186722 - 14 Sep 2022

Cited by 11 | Viewed by 1439

Abstract

A novel energetic co-crystal composed of hydrazinium 3-nitro-1,2,4-triazol-5-one (HNTO) and ammonium nitrate (AN), as a composite solid propellant oxidizer, was recently developed to substitute either pure ammonium perchlorate (AP) or nitrate. Unfortunately, the thermodynamic properties of this co-crystal or even the pure HNTO [...] Read more.

A novel energetic co-crystal composed of hydrazinium 3-nitro-1,2,4-triazol-5-one (HNTO) and ammonium nitrate (AN), as a composite solid propellant oxidizer, was recently developed to substitute either pure ammonium perchlorate (AP) or nitrate. Unfortunately, the thermodynamic properties of this co-crystal or even the pure HNTO are not available in the open literature. Therefore, in this work, the low-temperature heat capacities of HNTO and HNTO·AN co-crystal were measured in the temperature range from 213.15 K to 378.15 K using differential scanning calorimetry. By fitting the heat capacity data, the thermodynamic functions ΔH₂₉₈._15K, ΔG₂₉₈._15K, and ΔS₂₉₈._15K were derived. In addition, the standard molar energies of combustion Δ_cU° of HNTO and HNTO·AN co-crystal were determined, and from the combustion results, the standard molar enthalpies of combustion

Δ_{c} H_{m}^{o}

and formation

Δ_{f} H_{m}^{o}

of these energetic compounds were derived at T = 298.15 K. The set of thermochemical data has been proposed in this work for the first time and will be undoubtedly indispensable information for the development of energetic materials based on HNTO and HNTO·AN co-crystal. Full article

(This article belongs to the Special Issue Energetic Materials: Ignition and Combustion)

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9 pages, 1969 KiB

Open AccessArticle

Effect of Confinement on Detonation Velocity and Plate Dent Test Results for ANFO Explosive

by Vječislav Bohanek, Muhamed Sućeska, Mario Dobrilović and Philipp Hartlieb

Energies 2022, 15(12), 4404; https://0-doi-org.brum.beds.ac.uk/10.3390/en15124404 - 16 Jun 2022

Cited by 4 | Viewed by 1998

Abstract

The detonation properties of nonideal explosives are highly dependent on charge diameter and existence and properties of confinement. In this study, the effect of different confinements on the detonation velocity of ANFO explosives was experimentally determined along with the results of the plate [...] Read more.

The detonation properties of nonideal explosives are highly dependent on charge diameter and existence and properties of confinement. In this study, the effect of different confinements on the detonation velocity of ANFO explosives was experimentally determined along with the results of the plate dent test. ANFO explosive was selected as one of the most commonly used nonideal explosives. Following the measurement results, we found that the detonation velocity increased with increasing wall thickness, and the velocity increase was different for different confinement materials. A strong correlation existed between the ratio of the mass of confiner and explosive (M/C) and the detonation velocity (R = 0.995), and between (M/C) and the depth of the dent (δ) (R = 0.975). The data presented in this paper represent preliminary findings in developing a confinement model required for reliable numerical modeling of nonideal explosives. Full article

(This article belongs to the Special Issue Energetic Materials: Ignition and Combustion)

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10 pages, 2853 KiB

Open AccessArticle

Burning Velocities of Pyrotechnic Compositions: Effects of Composition and Granulometry

by Charles Rosères, Léo Courty, Philippe Gillard and Christophe Boulnois

Energies 2022, 15(11), 3942; https://0-doi-org.brum.beds.ac.uk/10.3390/en15113942 - 26 May 2022

Viewed by 1305

Abstract

Burning velocities of binary and ternary pyrotechnic compositions are measured in gutter. The study focuses on the determination of the joint influence of several parameters: oxidant/reducer ratio, reducer granulometry, and binder content. Measurements are performed following the standard NF T70-541 for burning velocity [...] Read more.

Burning velocities of binary and ternary pyrotechnic compositions are measured in gutter. The study focuses on the determination of the joint influence of several parameters: oxidant/reducer ratio, reducer granulometry, and binder content. Measurements are performed following the standard NF T70-541 for burning velocity estimation using an optical acquisition method. Binder content has a linear influence on the burning velocity with a pivot point in slope at supposed stoichiometry. Changing the granulometric class of metallic reducer shows to have different influences before and beyond a 20% diameter reduction. Full article

(This article belongs to the Special Issue Energetic Materials: Ignition and Combustion)

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12 pages, 31726 KiB

Open AccessArticle

A Study on the Effect of Initial Temperature on Combustion Characteristics of RDX Based on the Optical Diagnosis Methods

by Zhiyu Yan, Chen Song, Qianqian Li, Yulei Niu, Jinhua Wang and Zuohua Huang

Energies 2022, 15(7), 2421; https://0-doi-org.brum.beds.ac.uk/10.3390/en15072421 - 25 Mar 2022

Cited by 3 | Viewed by 1803

Abstract

The purpose of this work is to investigate the effect of different initial temperatures on the combustion characteristics of RDX materials. In the experiments, the electric heating plate below the RDX samples was controlled so that the initial temperatures were set to be [...] Read more.

The purpose of this work is to investigate the effect of different initial temperatures on the combustion characteristics of RDX materials. In the experiments, the electric heating plate below the RDX samples was controlled so that the initial temperatures were set to be 298, 323, 373, 423, and 473 K (below the material melting point), respectively. Three optical diagnostic methods were employed to capture the ignition process, flame thermal radiation, and NO distribution in the flame at different conditions. The results show that the increase in initial temperature can improve the reaction rate, shorten the ignition delay time, and increase the flame combustion intensity and speed, because of the earlier evaporation and pyrolysis process in the RDX samples. Increasing the initial temperature also enhances the thermal effect of the flame, which is related to the generation and consumption of NO to a certain extent. Full article

(This article belongs to the Special Issue Energetic Materials: Ignition and Combustion)

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14 pages, 1740 KiB

Open AccessArticle

Experiments with Pyrotechnic Compositions Based on a Mathematical Model—Part III: Comparative Analysis of Manufacturing Costs of Pyrotechnic Composition Producing an Acoustic Effect

by Krzysztof Barański and Jolanta Biegańska

Energies 2022, 15(4), 1331; https://0-doi-org.brum.beds.ac.uk/10.3390/en15041331 - 12 Feb 2022

Viewed by 1287

Abstract

The article presents a comparison of the influence of price change of the components of pyrotechnic compositions producing an acoustic effect on their manufacturing costs. The analysis was based on the prices of raw materials in 1981 and 2021. The influence of price [...] Read more.

The article presents a comparison of the influence of price change of the components of pyrotechnic compositions producing an acoustic effect on their manufacturing costs. The analysis was based on the prices of raw materials in 1981 and 2021. The influence of price fluctuations of individual raw materials on the final cost of composites was determined. The impact of price changes on the profitability of pyrotechnic composition manufacturing was evaluated for the adopted models. The conducted economic analysis allowed for the determination of pyrotechnic compositions characterised by the lowest manufacturing costs, in terms of the unit cost, and for the assumed industrial models. Full article

(This article belongs to the Special Issue Energetic Materials: Ignition and Combustion)

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16 pages, 5687 KiB

Open AccessArticle

Experiments with Pyrotechnic Compositions Based on a Mathematical Model: Part II Pyrotechnic Compositions Producing an Acoustic Effect with Optimum Properties

by Jolanta Biegańska and Krzysztof Barański

Energies 2022, 15(3), 794; https://0-doi-org.brum.beds.ac.uk/10.3390/en15030794 - 22 Jan 2022

Cited by 1 | Viewed by 1670

Abstract

The article presents a method of evaluating pyrotechnic compositions producing an acoustic effect. The aforementioned pyrotechnic compositions are used in firecrackers to simulate a cannon shot. Optimum compositions that were selected (Part I Evaluation of the applicability of mathematical models in developing pyrotechnic [...] Read more.

The article presents a method of evaluating pyrotechnic compositions producing an acoustic effect. The aforementioned pyrotechnic compositions are used in firecrackers to simulate a cannon shot. Optimum compositions that were selected (Part I Evaluation of the applicability of mathematical models in developing pyrotechnic compositions producing an acoustic effect) for testing were evaluated for their explosive and physicochemical properties. The following methods were used to evaluate suitability: measurement of the sound intensity level, the burning rate, and sensitivity to mechanical stimuli—friction and flash fire temperature. In addition, a test concerning the change in the properties of pyrotechnic compositions during storage was also performed. Full article

(This article belongs to the Special Issue Energetic Materials: Ignition and Combustion)

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16 pages, 1865 KiB

Open AccessArticle

Experiments with Pyrotechnic Compositions Based on a Mathematical Model—Part I Evaluation of the Applicability of Mathematical Models in Developing Pyrotechnic Compositions Producing an Acoustic Effect

by Jolanta Biegańska and Krzysztof Barański

Energies 2021, 14(24), 8548; https://0-doi-org.brum.beds.ac.uk/10.3390/en14248548 - 18 Dec 2021

Cited by 5 | Viewed by 2006

Abstract

This paper presents research on the development of pyrotechnic compositions producing an acoustic effect. These types of compositions are used in firecrackers to imitate a cannon shot—they are most frequently used during military exercises. The research was based on a mathematical model of [...] Read more.

This paper presents research on the development of pyrotechnic compositions producing an acoustic effect. These types of compositions are used in firecrackers to imitate a cannon shot—they are most frequently used during military exercises. The research was based on a mathematical model of an experiment. For environmental reasons, the replacement of the harmful oxidant Ba(NO₃)₂ by KClO₄ and NH₄ClO₄ was modelled. The compositions were tested for reliability and evaluated in terms of friction sensitivity and burning rate. This allowed for the verification of the effectiveness of the modelling carried out. Optimum compositions were selected for further research. Full article

(This article belongs to the Special Issue Energetic Materials: Ignition and Combustion)

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