{"title":"Wiley PEP Speaker Award 2024","authors":"","doi":"10.1002/prep.202480971","DOIUrl":"https://doi.org/10.1002/prep.202480971","url":null,"abstract":"","PeriodicalId":20800,"journal":{"name":"Propellants, Explosives, Pyrotechnics","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142217899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This research considers different storable oxidizer and fuel combinations for hybrid propulsion, looking for the most adequate candidates for mass and volume limited systems. High specific impulse Isp is the main indication for minimum mass, whereas high density specific impulse ρIsp is a good measure for smaller volume. Other aspects such as safety, handling, toxicity, burn rate, hypergolicity, and the oxidizer to fuel O/F ratio, may affect the final choice of propellant ingredient combination. For mass‐limited systems hydrogen peroxide H2O2 or nitrogen tetroxide N2O4 (the latter is toxic and hard to handle) oxidizers give the best results with most solid fuels (mainly hydroxyl‐terminated polybutadiene HTPB). For volume‐limited systems the same combinations may apply; however, in that case polyester fuel may be an adequate choice as well because of its high density. Nitrous oxide N2O is the most inadequate oxidizer for volume‐limited systems, yielding ρIsp lower by about 40 % compared to other oxidizers. Reducing the structure and insulation mass may result from decreasing the high‐pressure, high‐temperature section (the combustion chamber) and can be achieved from high O/F combinations employing N2O or H2O2 oxidizers. N2O gives relatively safe system, H2O2 enables hypergolic combinations, HNO3 is good for long‐term storage, whereas paraffin wax and expandable graphite additive yield high fuel regression rate and thrust. Overall, H2O2 oxidizer seems optimal for many operational aspects, but it should be chemically stabilized to minimize decomposition.
{"title":"Consideration of fuel and oxidizer combinations for mass and volume limited hybrid rocket motors","authors":"Michael Presman, Alon Gany","doi":"10.1002/prep.202400149","DOIUrl":"https://doi.org/10.1002/prep.202400149","url":null,"abstract":"This research considers different storable oxidizer and fuel combinations for hybrid propulsion, looking for the most adequate candidates for mass and volume limited systems. High specific impulse I<jats:sub>sp</jats:sub> is the main indication for minimum mass, whereas high density specific impulse ρI<jats:sub>sp</jats:sub> is a good measure for smaller volume. Other aspects such as safety, handling, toxicity, burn rate, hypergolicity, and the oxidizer to fuel O/F ratio, may affect the final choice of propellant ingredient combination. For mass‐limited systems hydrogen peroxide H<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub> or nitrogen tetroxide N<jats:sub>2</jats:sub>O<jats:sub>4</jats:sub> (the latter is toxic and hard to handle) oxidizers give the best results with most solid fuels (mainly hydroxyl‐terminated polybutadiene HTPB). For volume‐limited systems the same combinations may apply; however, in that case polyester fuel may be an adequate choice as well because of its high density. Nitrous oxide N<jats:sub>2</jats:sub>O is the most inadequate oxidizer for volume‐limited systems, yielding ρI<jats:sub>sp</jats:sub> lower by about 40 % compared to other oxidizers. Reducing the structure and insulation mass may result from decreasing the high‐pressure, high‐temperature section (the combustion chamber) and can be achieved from high O/F combinations employing N<jats:sub>2</jats:sub>O or H<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub> oxidizers. N<jats:sub>2</jats:sub>O gives relatively safe system, H<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub> enables hypergolic combinations, HNO<jats:sub>3</jats:sub> is good for long‐term storage, whereas paraffin wax and expandable graphite additive yield high fuel regression rate and thrust. Overall, H<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub> oxidizer seems optimal for many operational aspects, but it should be chemically stabilized to minimize decomposition.","PeriodicalId":20800,"journal":{"name":"Propellants, Explosives, Pyrotechnics","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142218005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ehtasimul Hoque, Subhajit Ghosal, Rajendra S. Patil, T. V. Jagadeeswar Rao
The cure kinetics of 4‐ (dimethylsilyl) butyl ferrocene grafted hydroxyl terminated polybutadiene (HTPB) with Isophorone diisocyante (IPDI) was investigated using differential scanning calorimeter (DSC). Furthermore, the catalytic effect of Iron (III) acetylacetonate (Fe(AA)3) and Dibutyltin dilaurate (DBTDL) on the curing reaction was studied. The experimental data was fitted to Kissinger and Ozawa models, and the kinetic parameters were expressed as Arrhenius activation energy (E), pre‐exponential factor (A) and rate constants. The Crane model was explored to determine the reaction order of the curing reaction. The study categorically showed that the activation energy of the curing reaction with 4‐ (dimethylsilyl) butyl ferrocene grafted HTPB is higher as compared to the pure hydroxyl terminated polybutadiene (HTPB) based system. However, the rate of curing reaction is higher with 4‐ (dimethylsilyl) butyl ferrocene grafted HTPB as compared to HTPB, and the viscosity build‐up data is too aligned with the DSC kinetic study. In addition, both catalysts increased the rate of the curing reaction but Fe(AA)3 displayed a superior catalytic effect.
{"title":"Study of curing kinetics of 4‐ (dimethylsilyl) butyl ferrocene grafted HTPB and effect of catalysts by differential scanning calorimetry","authors":"Ehtasimul Hoque, Subhajit Ghosal, Rajendra S. Patil, T. V. Jagadeeswar Rao","doi":"10.1002/prep.202400110","DOIUrl":"https://doi.org/10.1002/prep.202400110","url":null,"abstract":"The cure kinetics of 4‐ (dimethylsilyl) butyl ferrocene grafted hydroxyl terminated polybutadiene (HTPB) with Isophorone diisocyante (IPDI) was investigated using differential scanning calorimeter (DSC). Furthermore, the catalytic effect of Iron (III) acetylacetonate (Fe(AA)<jats:sub>3</jats:sub>) and Dibutyltin dilaurate (DBTDL) on the curing reaction was studied. The experimental data was fitted to Kissinger and Ozawa models, and the kinetic parameters were expressed as Arrhenius activation energy (E), pre‐exponential factor (A) and rate constants. The Crane model was explored to determine the reaction order of the curing reaction. The study categorically showed that the activation energy of the curing reaction with 4‐ (dimethylsilyl) butyl ferrocene grafted HTPB is higher as compared to the pure hydroxyl terminated polybutadiene (HTPB) based system. However, the rate of curing reaction is higher with 4‐ (dimethylsilyl) butyl ferrocene grafted HTPB as compared to HTPB, and the viscosity build‐up data is too aligned with the DSC kinetic study. In addition, both catalysts increased the rate of the curing reaction but Fe(AA)<jats:sub>3</jats:sub> displayed a superior catalytic effect.","PeriodicalId":20800,"journal":{"name":"Propellants, Explosives, Pyrotechnics","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142218038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}