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Ideal Specific Impulse of Solid Rocket Propellants Based on AP/GAP/closo-Dodecaborate ([B12H12]2-) Salts

Rao Muddamarri Hanumantha, Badgujar Dilip M.

Central European Journal of Energetic Materials

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2024

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Vol. 21, no. 2

153--170

EN

Elemental boron (B) is an exciting high-energy substance and falls into the group of metalloid chemical elements. It possesses the second-highest calorific value among elements fit for use in the production of propellants and explosives. However, practical applications of B come upon challenges related to ignition and combustion due to the formation of a B2O3 layer on its surface. Elemental B does not readily combust; it necessitates high-purity oxygen for the combustion process and tends to clump, leading to incomplete combustion. To address these issues, this study explores the use of closo-dodecaborate salts ([B12H12]2‒) as an alternative to B powder. The investigation focuses on three solid rocket propellant formulations incorporating closo-dodecaborate salts, with ammonium perchlorate (AP) as the oxidizer and GAP as the binder. The EXPLO5 code version V6.03 was employed to calculate the ideal specific impulse (Isp). The incorporation of closododecaborate salts in the propellant composition demonstrates major potential, and the AP/GAP/closo-dodecaborate salt formulations exhibit competitive theoretical performance, mainly in the context of low metalized compositions.

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Computational Determination of the Specific Impulse of Solid Rocket Propellant Compositions of closo-Dodecaborate ([B₁₂H₁₂]2‒) Salts with HTPB Binder and Ammonium Perchlorate as an Oxidizer

Rao Muddamarri Hanumantha

Central European Journal of Energetic Materials

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2023

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Vol. 20, no. 4

386--399

EN

Boron (B) powder in elemental form is a very attractive high-energy material and it is a metalloid chemical element. B powder has the second highest heat of explosion of any element that can be adopted as an energetic material in dealing with propellants and explosives. In practical situations, B has problems with ignition and combustion due to the formation of a B₂O₃ layer on its surface. B cannot burn easily; it requires ultra-pure oxygen during the combustion process and also undergoes agglomeration due to which incomplete combustion of the B particles in the propellant composition occurs. Hence in order to address these issues, we introduced closo-dodecaborate ([B₁₂H₁₂]2‒) salts into a solid rocket propellant composition instead of B powder. In the present work, three solid rocket propellant compositions based on closo-dodecaborate salts were theoretically investigated. The specific impulse (Isp) was calculated for three closo-dodecaborate [B₁₂H₁₂]2‒ based propellant compositions using the EXPLO5 code version V6.03. The performance values of the closo-dodecaborate [B₁₂H₁₂]2‒ salts based propellant compositions were compared with those of pure aluminium (Al)-based composite propellant. Using the EXPLO5 code (V6.03); hydroxyl-terminated polybutadiene (HTPB) and ammonium perchlorate (NH₄ClO₄, AP) were used as binder and oxidizer respectively. closo-Dodecaborate salts-HTPB-AP formulations have good theoretical performance; it was observed that the presence of a closo-dodecaborate salt in the propellant composition can lead to very good performance, and they are potential candidates as fuels and/or fuel additives in propellant compositions for missile and rocket applications.

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Research Output Software for Energetic Materials Based on Observational Modelling 2.2 (RoseBoom2.2©) - Update to Calculate the Specific Impulse, Detonation Velocity, Detonation Pressure and Density for CHNO Mixtures Using the Supersloth-function

Klapötke Thomas M., Wahler Sabrina

Central European Journal of Energetic Materials

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2022

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Vol. 19, no. 3

295--310

EN

RoseBoom2.2© can calculate parameters for CHNO mixtures, automatically minimizing user-input. In the present study, RoseBoom’s© results were compared to 518 EXPLO5 calculations. The new version of RoseBoom© can calculate a variety of parameters for mixtures. The detonation pressure and detonation velocity, and the specific impulse were calculated using different methods. In the present study different approaches for calculating the average sum formula have been evaluated

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Numerical Modelling of Detonation Reaction Zone of Nitromethane by EXPLO5 Code and Wood and Kirkwood Theory

Štimac Barbara, Chan Hay Yee Serene, Kunzel Martin, Suceska Muhamed

Central European Journal of Energetic Materials

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2020

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Vol. 17, no. 2

239--261

EN

The detonation reaction zone of nitromethane (NM) has been extensively studied both experimentally and theoretically. The measured particle velocity profile of NM shows the existence of a sharp spike followed by a rapid drop over the first 5-10 ns (fast reaction). The sharp spike is followed by a gradual decrease (slow reactions) which terminate after approximately 50-60 ns when the CJ condition is attained. Based on experimental data, the total reaction zone length is estimated to be around 300 μm. Some experimental observations, such as the reaction zone width and the diameter effect, can be satisfactorily reproduced by numerical modelling, provided an appropriate reaction rate model is known. Here we describe the model for numerical modelling of the steady state detonation of NM. The model is based on the coupling thermochemical code EXPLO5 with the Wood-Kirkwood detonation theory, supplemented with different reaction rate models. The constants in the rate models are calibrated based on experimentally measured particle velocity profiles and the detonation reaction zone width. It was found that the model can describe the experimentally measured total reaction time (width of reaction zone) and the particle velocitytime profile of NM. It was found also that the reaction rate model plays a key role on the shape of the shock wave front. In addition, the model can predict the detonation parameters (D, pCJ, TCJ, VCJ, etc.) and the effect of charge diameter on the detonation parameters.