Effect of metal additives on neutralization and characteristics of AP/HTPB solid propellants

Vellaisamy, Uma; Biswas, Shelly

doi:10.1016/j.combustflame.2020.08.006

Cited by 42 publications

(9 citation statements)

References 16 publications

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“…The decreasing effect on the burning rate of the particle mixture Al+Mg (S2) is confirmed by the motor test. Nevertheless, further research on this behavior needs to be done, especially considering that Biswas and Vellaisamy reported an opposite effect for AP‐based propellants [28].…”

Section: Resultsmentioning

confidence: 99%

ADN Solid Propellants with High Burning Rates as Booster Material for Hypersonic Applications

Sims

Fischer

Tagliabue

2022

Propellants Explo Pyrotec

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RAM-and SCRAM-Jet engines can not generate static thrust and only work at high speeds. This starting velocity of the motor v 0 is usually generated by carrier rockets or boosters, which mostly use solid propellants based on ammonium perchlorate (AP) and hydroxyl-terminated polybutadiene (HTPB). Modern solid propellants based on ammonium dinitramide (ADN) and Glycidyl Azide Polymer (GAP) have significant advantages in terms of environmental compatibility and thermodynamic performance. In the present work, it is shown that the already high burning rate of ADN solid propellants can be more than doubled by means of metallic fibers, which significantly increases the thrust of such engines. In order to achieve such results, 3 wt% of AlÀ Mg alloy fibers are added to the propellant. A formulation with 3 mm long fibres shows the highest burning rate with 84.0 mm/s at 26.5 MPa. Small scale motor tests confirm these investigations. The burning mechanism is studied by SEM/EDX investigations and by measuring the thermal conductivity. These show that the fibres remain on the burning surface and thus transfer the heat from the flame to the depth of the propellant. The thermal conductivity of samples with AlMg5 fibers is about 22 % higher than the reference.

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Section: Resultsmentioning

confidence: 99%

ADN Solid Propellants with High Burning Rates as Booster Material for Hypersonic Applications

Sims

Fischer

Tagliabue

2022

Propellants Explo Pyrotec

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“…The Crawford bomb, similar than describes in the literature [23,24], consists of a combustion chamber, in which the propellant specimen containing l size, and a 10 × 10 cm square cross-section, is subjected to burning at constant pressure, controlled by the inert industrial grade nitrogen gas supply. The gases generated leave the chamber through an orifice located in the equipment and the pressure is controlled during burning and recorded during the test.…”

Section: Crawford Bomb Test: a And N Of The Vielle's Lawmentioning

confidence: 99%

A Study of the Influence of Storage Time of Uncured Propellants on the Final Properties of the Composite in Multi‐Batch Processes on an Industrial Scale

Cunha

Rocco

2021

Propellants Explo Pyrotec

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In the Brazilian Aerospace Program, even though all developed rocket motors are manufactured in the same plant of the Department of Aerospace Science and Technology, differences are observed in the magnitude of the masses applied in each motor. Thus, depending on the volume of the combustion chamber, it is common for the casting to carry out multi-batch processes when a required mass of solid propellant is greater than the maximum capacity of the reactor. In this context, the studies that systematically evaluate multi-batch processes on an industrial scale of composite propellants based on polyurethanes obtained from HTPB are incipient. Furthermore, each batch preparation of the casting process for large motors is carried out on different days, so that each of these has a different storage time until the day of the effective casting. As a result, this wait can generate changes in the properties of the propellant grain as a whole, which can modify the motor's performance. Thusly, through the analysis of data of multi-batch processes, the present study evaluated the influence of the storage time in the preparation of the propellant and on the final properties of the grain. It was concluded that the grain becomes softer with a reduction in its hardness, greater elongation at break, and less modulus for batches with longer storage times before casting.

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“…The propellant samples were weighed 5 times emerged and immersed in silicone (d = 0.963 g cm À3 ) using the Mettler density determination kit from the Mettler XPE205 semi-analytical balance, similar than describe in the literature. [29][30][31] The results were compared, and the influence of the size and type of the reactor on the cited properties were investigated. The evaluation of the influence of the interruption of heating during curing on the final properties of the cured propellant obtained in process D was also determined following the same methodology.…”

Section: Mechanical Characterization Of the Propellant Grainmentioning

confidence: 99%

The influence of the type and size of the reactor and the influence of the heating interruption during curing on the solid composite propellant properties

Cunha

Rocco

2021

J of Applied Polymer Sci

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The solid composite propellant is a viscoelastic material that retains the treatment received during its all-useful life. As a result, its manufacturing conditions induce differences in its final mechanical properties. The present study aims to evaluate the influence of the type and size of the reactor and the effects of the heating interruption during curing on the final mechanical properties of the propellant. Thus, four production processes with identical propellant formulations were performed in four different reactors. One of them was vertical, while the others were horizontal reactors. The heating interruption during curing was performed in 10 samples, at different moments of the curing process and with different duration. The study determines that vertical reactors tend to produce propellants less rigid than those produced in the horizontal type. In addition, the bigger the reactor size, the less rigid the propellant becomes. Finally, the heating interruptions at the beginning of the curing process tend to be insignificant. However, when they occur in an advanced stage of the curing process, they tend to hinder the curing progress, being more significant for interruptions of medium duration.

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Effect of metal additives on neutralization and characteristics of AP/HTPB solid propellants

Cited by 42 publications

References 16 publications

ADN Solid Propellants with High Burning Rates as Booster Material for Hypersonic Applications

ADN Solid Propellants with High Burning Rates as Booster Material for Hypersonic Applications

A Study of the Influence of Storage Time of Uncured Propellants on the Final Properties of the Composite in Multi‐Batch Processes on an Industrial Scale

The influence of the type and size of the reactor and the influence of the heating interruption during curing on the solid composite propellant properties

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