Experimental study of severity level of structural discontinuities in paraffin grains of hybrid propellant rocket

Andrianov, Artem; Lee, Jung-Pyo; Shynkarenko, Olexiy; Simone, Domenico; Bertoldi, Artur Elias De Morais

doi:10.1016/j.actaastro.2019.06.015

Cited by 8 publications

(5 citation statements)

References 13 publications

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“…A number of paraffin structural enhancement techniques with the use of polymer additives have been researched by various institutions (Mengu and Kumar 2018) which generally show that these additives reduce the regression rate of the fuel, often by increasing the melt viscosity, resulting in reduced fuel entrainment. Other research has been conducted into the effect that structural discontinuities will have on the combustion performance of a motor (Andrianov et al 2019). The preliminary analysis shows that induced cracks do not lead to immediate failure of the grain, but there is a clear regression inconsistency which can lead to chamber burn through if the burn time is long enough.…”

Section: Structural Considerationsmentioning

confidence: 99%

Explicit Modelling of the Ignition Transient Structural Response of a Paraffin Wax Hybrid Rocket Motor Fuel Grain

Veale

Adali

Pitot

et al. 2021

J. Aerosp. Technol. Manag.

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Paraffin wax has been identified as a hybrid rocket motor fuel, which offers enhanced regression rates and improved combustion performance. While various investigations into the performance of this class of fuels are being conducted around the world, the consideration of its structural performance is often overlooked. The research presented here establishes a simplified, yet accurate method of defining the structural performance of a paraffin wax hybrid fuel grain to be introduced early in the design phase of a motor. The use of the Johnson-Cook (J-C) material model has been verified to work within the "low speed" ignition range experienced in paraffin wax/N 2 O hybrid motors, and therefore is used to predict failure in a variety of motors. The resultant stress profiles within the grains indicate that the grain outer to inner diameter (OD/ID) ratio, as well as the outer diameter (OD) itself, play an important role in the grain ability to withstand the loading conditions applied. Additionally, the grain structural properties, and the stiffness of the combustion chamber affect the severity of the internal stresses in the grain. The feasibility of large-scale pure paraffin wax grains without structural enhancement additives is thus found to be poor. Fuel additives should be considered for structural enhancement.

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Section: Structural Considerationsmentioning

confidence: 99%

Explicit Modelling of the Ignition Transient Structural Response of a Paraffin Wax Hybrid Rocket Motor Fuel Grain

Veale

Adali

Pitot

et al. 2021

J. Aerosp. Technol. Manag.

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“…While certain additives can be utilized to improve the mechanical properties, this improvement may come to the detriment of other important parameters of the propellant, including the regression rate. Furthermore, as highlighted by Andrianov et al [27], specific conditions during the manufacturing process can lead to the formation of radial cracks in relatively small solid propellant grains, resulting in local overheating of the structural casing and potentially jeopardizing the structural integrity of the motor. Additionally, the presence of a radial crack in a paraffin grain can induce alterations in the initial shape of the grain's port due to the combustion within the crack.…”

Section: Introductionmentioning

confidence: 99%

Experimental Research into an Innovative Green Propellant Based on Paraffin–Stearic Acid and Coal for Hybrid Rocket Engines

Cican,

Paraschiv,

Buturache

et al. 2024

Inventions

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This study focuses on an innovative green propellant based on paraffin, stearic acid, and coal, used in hybrid rocket engines. Additionally, lab-scale firing tests were conducted using a hybrid rocket motor with gaseous oxygen as the oxidizer, utilizing paraffin-based fuels containing stearic acid and coal. The mechanical performance results revealed that the addition of stearic acid and coal improved the mechanical properties of paraffin-based fuel, including tensile, compression, and flexural strength, under both ambient and sub-zero temperatures (−21 °C). Macrostructural and microstructural examinations, conducted through optical and scanning electron microscopy (SEM), highlighted its resilience, despite minimal imperfections such as impurities and micro-voids. These characteristics could be attributed to factors such as raw material composition and the manufacturing process. Following the mechanical tests, the second stage involved conducting a firing test on a hybrid rocket motor using the new propellant and gaseous oxygen. A numerical simulation was carried out using ProPEP software to identify the optimal oxidant-to-fuel ratio for the maximum specific impulse. Following simulations, it was observed that the specific impulse for the paraffin and for the new propellant differs very little at each oxidant-to-fuel (O/F) ratio. It is noticeable that the maximum specific impulse is achieved for both propellants around the O/F value of 2.2. It was observed that no hazardous substances were present, unlike in traditional solid propellants based on ammonium perchlorate or aluminum. Consequently, there are no traces of chlorine, ammonia, or aluminum-based compounds after combustion. The resulting components for the simulated motor include H2, H2O, O2, CO2, CO, and other combinations in insignificant percentages. It is worth noting that the CO concentration decreases with an increase in the O/F ratio for both propellants, and the differences between concentrations are negligible. Additionally, the CO2 concentration peaks at an O/F ratio of around 4.7. The test proceeded under normal conditions, without compromising the integrity of the test stand and the motor. These findings position the developed propellant as a promising candidate for applications in low-temperature hybrid rocket technology and pave the way for future advancements.

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“…No caso das parafinas puras, Andrianov et al apontaram que embora não seja possível estabelecer de forma geral que defeitos estruturais tenham influência significativa no processo de queima ou na ocorrência de falha catastrófica, é válido afirmar que as condições do processo de fabricação podem levar à formação de trincas, mesmo em blocos de pequenas dimensões, o que por sua vez pode conduzir a um superaquecimento do motor e eventualmente comprometer a sua integridade estrutural. Além disso, os autores demonstraram experimentalmente que uma trinca radial afeta apreciavelmente a evolução do perfil de queima do canal interno (ANDRIANOV et al, 2019).…”

Section: Combustíveis Oxidantesunclassified

“…Por sua vez, o desempenho destes compósitos pode ser afetado pelo nível de homogeneidade macro e microestrutural (miscibilidade) atingido por um dado processo de fabricação de amostras. Além disso, parece desejável, sob o ponto de vista da aplicabilidade destes compósitos, que o método de preparo seja capaz de produzir amostras homogêneas e dimensionalmente regulares, isentas de defeitos estruturais como trincas e fissuras, com geometria simples e comum em combustíveis estudados para sistemas híbridos, qual seja, a geometria cilíndrica monoperfurada (ANDRIANOV et al, 2019). Uma abordagem integrada destas variáveis pode limitar a faixa de formulações em função da viabilidade da sua preparação em escala laboratorial, segundo um método potencialmente passível de aumento de escala.…”

Section: Preparação De Compósitos Entre Polímeros E Parafinasunclassified

“…Como feito anteriormente, a homogeneidade macroscópica foi avaliada por inspeção visual de discos com cerca de 1,0 mm de espessura, cortados em torno mecânico a partir do terço médio das peças. Estes discos são apresentados na algumas objeções apontadas na literatura (ANDRIANOV et al, 2019;PISCITELLI et al, 2015;SACCONE et al, 2015;STOBER et al, 2019).…”

Section: New_3v_00unclassified

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Preparação e caracterização de compósitos à base de polietileno, parafina e nitrato de amônio para aplicação em propulsão hibrida

Araújo¹

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Agradeço à minha família, particularmente aos meus avós Hélio (in memoriam)e Clara e à minha tia Lasthenia (in memoriam), cujo apoio, dedicação e exemplos foram e continuam a ser fundamentais em minha vida.Agradeço ao meu orientador, Dr. Ricardo Vieira, pela disponibilidade, pelo estímulo à criatividade e à independência intelectual e pela confiança em mim depositada.Agradeço ao meu co-orientador, Dr. Leonardo Henrique Gouvêa, por me apresentar ao mundo instigante da propulsão híbrida e pelas sugestões pertinentes. Agradeço ao Dr. Leandro José Maschio por todo o apoio prestado ao longo deste trabalho, pelas discussões produtivas e, sobretudo, pela amizade com que me honrou. Agradeço a todos os profissionais do Laboratório Associado de Combustão e Propulsão do Instituto Nacional de Pesquisas Espaciais (LABCP-INPE), cuja colaboração foi essencial para a realização desta Tese, especialmente à Dra.

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Experimental study of severity level of structural discontinuities in paraffin grains of hybrid propellant rocket

Cited by 8 publications

References 13 publications

Explicit Modelling of the Ignition Transient Structural Response of a Paraffin Wax Hybrid Rocket Motor Fuel Grain

Explicit Modelling of the Ignition Transient Structural Response of a Paraffin Wax Hybrid Rocket Motor Fuel Grain

Experimental Research into an Innovative Green Propellant Based on Paraffin–Stearic Acid and Coal for Hybrid Rocket Engines

Preparação e caracterização de compósitos à base de polietileno, parafina e nitrato de amônio para aplicação em propulsão hibrida

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