Closed bomb testing is a prominent means of characterizing the combustion behavior of solid gun propellants. This sub‐scale test allows the propellant to burn in a constant volume environment, where the resulting pressure‐time trace can be collected via a pressure transducer. Historically, numerical procedures have been developed to determine the burn rates of the gun propellants from these pressure‐time traces; however, no standardized procedure exists to determine the burn rates of grains with variable surface thermochemistry and ignition criteria. To address this capability gap, a non‐linearly constrained, multivariate optimization algorithm has been developed to decouple propellant grain surfaces and determine surface‐specific burn rates [1]. In this work, the optimization algorithm as well as the legacy Excel‐based Closed Bomb (XLCB) program [2] were used to determine the burn rates of homogeneous, deterred, and layered propellants from experimental data. Closed bomb simulations using these burn rates were then conducted with the two‐phase, multidimensional, interior ballistics solver, iBallistix [3]. The maximum mean error between the simulated and experimental pressure‐time curves was 6.8 % for the optimization algorithm and 23.8 % for XLCB, showing a marked improvement with our new approach. Furthermore, the approach discussed herein improves burn rate predictions of complex solid gun propellants when compared with legacy closed bomb data reduction analysis programs.
{"title":"A numerical determination of complex solid gun propellant burn rates through closed bomb simulation","authors":"Christopher Houthuysen, Nicholaus Parziale","doi":"10.1002/prep.202300258","DOIUrl":"https://doi.org/10.1002/prep.202300258","url":null,"abstract":"Closed bomb testing is a prominent means of characterizing the combustion behavior of solid gun propellants. This sub‐scale test allows the propellant to burn in a constant volume environment, where the resulting pressure‐time trace can be collected via a pressure transducer. Historically, numerical procedures have been developed to determine the burn rates of the gun propellants from these pressure‐time traces; however, no standardized procedure exists to determine the burn rates of grains with variable surface thermochemistry and ignition criteria. To address this capability gap, a non‐linearly constrained, multivariate optimization algorithm has been developed to decouple propellant grain surfaces and determine surface‐specific burn rates [1]. In this work, the optimization algorithm as well as the legacy Excel‐based Closed Bomb (XLCB) program [2] were used to determine the burn rates of homogeneous, deterred, and layered propellants from experimental data. Closed bomb simulations using these burn rates were then conducted with the two‐phase, multidimensional, interior ballistics solver, iBallistix [3]. The maximum mean error between the simulated and experimental pressure‐time curves was 6.8 % for the optimization algorithm and 23.8 % for XLCB, showing a marked improvement with our new approach. Furthermore, the approach discussed herein improves burn rate predictions of complex solid gun propellants when compared with legacy closed bomb data reduction analysis programs.","PeriodicalId":508060,"journal":{"name":"Propellants, Explosives, Pyrotechnics","volume":"37 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140974606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kai Xin, Rongjie Yang, Kairui Yang, Jianmin Li, Jinxian Zhai
Considering the high toxicity of toluene diisocyanate (TDI) and the low reactivity of isophorone diisocyanate (IPDI), a low‐toxicity curing agent, dimer acid diisocyanate (DDI), was used to cross‐link HTPB elastomers and propellants. The unique long‐chain structure of DDI not only ensures the elastic modulus and tensile strength of the elastomer, but also improves the flexibility to some extent. The long flexible chains promote the segment movement, which is very important for the formation of hydrogen bonds between segments. The chemical cross‐linking network and hydrogen bonding association play a significant role in the mechanical properties of the HTPB/DDI system. The relationship between the mole ratio of ‐NCO to ‐OH (R‐value) and the mechanical properties of HTPB/DDI elastomers were also investigated. In the range of R‐value from 0.85 to 1.2, the elastic modulus and tensile strength first increase and then decrease, and the elongation at break first decreases and then increases. Under the same curing conditions, the elastic modulus and tensile strength of the HTPB/DDI propellant are similar to the HTPB/TDI propellant. For the HTPB/AP/Al propellants and HTPB/AP/RDX/Al propellants, the HTPB/DDI system has lower burning rates in the range of 5–19 MPa than the HTPB/TDI system and HTPB/IPDI system. The application of DDI can reduce the burning rates of the propellant without adding any burning rate modifiers. It is considered that DDI can replace TDI and IPDI as a new curing agent with low toxicity and moderate reactivity for HTPB systems.
{"title":"Hydroxyl‐terminated polybutadiene(HTPB) propellants cross‐linked by dimer acid diisocyanate (DDI): Cross‐linking network and properties","authors":"Kai Xin, Rongjie Yang, Kairui Yang, Jianmin Li, Jinxian Zhai","doi":"10.1002/prep.202300259","DOIUrl":"https://doi.org/10.1002/prep.202300259","url":null,"abstract":"Considering the high toxicity of toluene diisocyanate (TDI) and the low reactivity of isophorone diisocyanate (IPDI), a low‐toxicity curing agent, dimer acid diisocyanate (DDI), was used to cross‐link HTPB elastomers and propellants. The unique long‐chain structure of DDI not only ensures the elastic modulus and tensile strength of the elastomer, but also improves the flexibility to some extent. The long flexible chains promote the segment movement, which is very important for the formation of hydrogen bonds between segments. The chemical cross‐linking network and hydrogen bonding association play a significant role in the mechanical properties of the HTPB/DDI system. The relationship between the mole ratio of ‐NCO to ‐OH (R‐value) and the mechanical properties of HTPB/DDI elastomers were also investigated. In the range of R‐value from 0.85 to 1.2, the elastic modulus and tensile strength first increase and then decrease, and the elongation at break first decreases and then increases. Under the same curing conditions, the elastic modulus and tensile strength of the HTPB/DDI propellant are similar to the HTPB/TDI propellant. For the HTPB/AP/Al propellants and HTPB/AP/RDX/Al propellants, the HTPB/DDI system has lower burning rates in the range of 5–19 MPa than the HTPB/TDI system and HTPB/IPDI system. The application of DDI can reduce the burning rates of the propellant without adding any burning rate modifiers. It is considered that DDI can replace TDI and IPDI as a new curing agent with low toxicity and moderate reactivity for HTPB systems.","PeriodicalId":508060,"journal":{"name":"Propellants, Explosives, Pyrotechnics","volume":"136 24","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140976890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hydroxylammonium cyclo‐pentazolate (NH3OHN5), as one of the poly‐nitrogen compounds, has a broad prospect in the field of energetic materials, due to its high specific impulse, high detonation velocity, and the pollution‐free products. In this paper, the thermal decomposition behavior of NH3OHN5 was studied by differential scanning calorimetry (DSC) using four heating rates (2, 5, 8, 10 °C min−1). The apparent activation energy (EK,O=114.31 kJ mol−1), the pre‐exponential factor (AK=4.78×1011 s−1) and the critical temperature of the thermal explosion (Tb=108.08 °C) of NH3OHN5 were calculated by Kissinger and Ozawa method under non‐isothermal heating conditions. The compatibility of NH3OHN5 with 1,3,5‐trinitro‐1,3,5‐triazacyclohexane (RDX), 1,3,5,7‐tetranitro‐1,3,5,7‐tetraazacyclooctane (HMX), 2,4,6,8,10,12‐hexanitro‐2,4,6,8,10,12‐hexaza‐isowurtzitane (CL‐20), ammonium perchlorate (AP), and hydroxy‐terminated polybutadiene (HTPB) were tested and judged based on a standard agreement (STANAG‐4147). The DSC results showed that NH3OHN5/HMX, NH3OHN5/RDX, NH3OHN5/CL‐20, NH3OHN5/AP and NH3OHN5/HTPB had good compatibility.
{"title":"Thermal decomposition kinetics and compatibility of NH3OHN5","authors":"Xiang Chen, Chenguang Zhu, Bingcheng Hu, Chong Zhang","doi":"10.1002/prep.202300141","DOIUrl":"https://doi.org/10.1002/prep.202300141","url":null,"abstract":"Hydroxylammonium cyclo‐pentazolate (NH3OHN5), as one of the poly‐nitrogen compounds, has a broad prospect in the field of energetic materials, due to its high specific impulse, high detonation velocity, and the pollution‐free products. In this paper, the thermal decomposition behavior of NH3OHN5 was studied by differential scanning calorimetry (DSC) using four heating rates (2, 5, 8, 10 °C min−1). The apparent activation energy (EK,O=114.31 kJ mol−1), the pre‐exponential factor (AK=4.78×1011 s−1) and the critical temperature of the thermal explosion (Tb=108.08 °C) of NH3OHN5 were calculated by Kissinger and Ozawa method under non‐isothermal heating conditions. The compatibility of NH3OHN5 with 1,3,5‐trinitro‐1,3,5‐triazacyclohexane (RDX), 1,3,5,7‐tetranitro‐1,3,5,7‐tetraazacyclooctane (HMX), 2,4,6,8,10,12‐hexanitro‐2,4,6,8,10,12‐hexaza‐isowurtzitane (CL‐20), ammonium perchlorate (AP), and hydroxy‐terminated polybutadiene (HTPB) were tested and judged based on a standard agreement (STANAG‐4147). The DSC results showed that NH3OHN5/HMX, NH3OHN5/RDX, NH3OHN5/CL‐20, NH3OHN5/AP and NH3OHN5/HTPB had good compatibility.","PeriodicalId":508060,"journal":{"name":"Propellants, Explosives, Pyrotechnics","volume":" 40","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139792374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hydroxylammonium cyclo‐pentazolate (NH3OHN5), as one of the poly‐nitrogen compounds, has a broad prospect in the field of energetic materials, due to its high specific impulse, high detonation velocity, and the pollution‐free products. In this paper, the thermal decomposition behavior of NH3OHN5 was studied by differential scanning calorimetry (DSC) using four heating rates (2, 5, 8, 10 °C min−1). The apparent activation energy (EK,O=114.31 kJ mol−1), the pre‐exponential factor (AK=4.78×1011 s−1) and the critical temperature of the thermal explosion (Tb=108.08 °C) of NH3OHN5 were calculated by Kissinger and Ozawa method under non‐isothermal heating conditions. The compatibility of NH3OHN5 with 1,3,5‐trinitro‐1,3,5‐triazacyclohexane (RDX), 1,3,5,7‐tetranitro‐1,3,5,7‐tetraazacyclooctane (HMX), 2,4,6,8,10,12‐hexanitro‐2,4,6,8,10,12‐hexaza‐isowurtzitane (CL‐20), ammonium perchlorate (AP), and hydroxy‐terminated polybutadiene (HTPB) were tested and judged based on a standard agreement (STANAG‐4147). The DSC results showed that NH3OHN5/HMX, NH3OHN5/RDX, NH3OHN5/CL‐20, NH3OHN5/AP and NH3OHN5/HTPB had good compatibility.
{"title":"Thermal decomposition kinetics and compatibility of NH3OHN5","authors":"Xiang Chen, Chenguang Zhu, Bingcheng Hu, Chong Zhang","doi":"10.1002/prep.202300141","DOIUrl":"https://doi.org/10.1002/prep.202300141","url":null,"abstract":"Hydroxylammonium cyclo‐pentazolate (NH3OHN5), as one of the poly‐nitrogen compounds, has a broad prospect in the field of energetic materials, due to its high specific impulse, high detonation velocity, and the pollution‐free products. In this paper, the thermal decomposition behavior of NH3OHN5 was studied by differential scanning calorimetry (DSC) using four heating rates (2, 5, 8, 10 °C min−1). The apparent activation energy (EK,O=114.31 kJ mol−1), the pre‐exponential factor (AK=4.78×1011 s−1) and the critical temperature of the thermal explosion (Tb=108.08 °C) of NH3OHN5 were calculated by Kissinger and Ozawa method under non‐isothermal heating conditions. The compatibility of NH3OHN5 with 1,3,5‐trinitro‐1,3,5‐triazacyclohexane (RDX), 1,3,5,7‐tetranitro‐1,3,5,7‐tetraazacyclooctane (HMX), 2,4,6,8,10,12‐hexanitro‐2,4,6,8,10,12‐hexaza‐isowurtzitane (CL‐20), ammonium perchlorate (AP), and hydroxy‐terminated polybutadiene (HTPB) were tested and judged based on a standard agreement (STANAG‐4147). The DSC results showed that NH3OHN5/HMX, NH3OHN5/RDX, NH3OHN5/CL‐20, NH3OHN5/AP and NH3OHN5/HTPB had good compatibility.","PeriodicalId":508060,"journal":{"name":"Propellants, Explosives, Pyrotechnics","volume":"42 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139852213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Spotlight on Energetic Materials Scientists Forthcoming Meetings. The International Pyrotechnics Society Preview","authors":"","doi":"10.1002/prep.202480271","DOIUrl":"https://doi.org/10.1002/prep.202480271","url":null,"abstract":"","PeriodicalId":508060,"journal":{"name":"Propellants, Explosives, Pyrotechnics","volume":"7 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139967027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：