The new CL-20(hexanitrohexaazaisowurtzitane)type aluminized explosives in the overdrive detonation(ODD)conditions of the core problem is how to accurately represent the state of the overdrive detonation products.To th...The new CL-20(hexanitrohexaazaisowurtzitane)type aluminized explosives in the overdrive detonation(ODD)conditions of the core problem is how to accurately represent the state of the overdrive detonation products.To this end,this paper is based on the impedance matching method to test the ODD conditions of CL-20 type aluminium explosive particle velocity.Calculated the interfacial pressure of the shock wave in different media.Determined the characteristic parameters of the reaction zone of the detonation of CL-20 aluminized explosives.Calibrated the parameters of the JoneseWilkinseLee(JWL)+γ equation for the detonation products(DPs).Revealed the effect of different DPs equation of state(EOS)on the Hugoniot pressure of ODD.The results indicate that when the content of aluminum powder ranges from 0%to 30%,the duration of the ODD reaction zone and the width of the detonation reaction zone of the CL-20-based aluminized explosive are directly proportional to the content of aluminum powder.The width of the detonation reaction zone is increased by 1.97 times to 2.7 times compared to that of the reaction zone without the addition of aluminum powder.However,the energy release efficiency of the detonation reaction zone is inversely proportional to the content of aluminum powder.When the aluminum powder content was held constant,the incorporation of AP caused a 25%reduction in the energy release efficiency of the detonation reaction zone.Compared with existing ODD state equations,the JWL +γ equation is superior in calibrating overpressure Hugoniot data and the isentropic expansion in the C-J state.The deviation between calculated pressure results and experimental measurements is within 6%.展开更多
Taking CL-20(Hexanitrohexaazaisowurtzitane)-based aluminized explosives with high gurney energy as the research object, this research experimentally investigates the work capability of different aluminized explosive f...Taking CL-20(Hexanitrohexaazaisowurtzitane)-based aluminized explosives with high gurney energy as the research object, this research experimentally investigates the work capability of different aluminized explosive formulations when driving metal flyer plates in the denotation wave propagation direction.The research results showed that the formulations with 43 μm aluminum(Al) powder particles(The particle sizes of Al powder were in the range of 2~43 μm) exhibited the optimal performance in driving flyer plates along the denotation wave propagation direction. Compared to the formulations with Al powder 13 μm, the formulations with Al powder 2 μm delivered better performance in accelerating metal flyer plates in the early stage, which, however, turned to be poor in the later stage. The CL-20-based explosives containing 25% Al far under-performed those containing 15% Al. Based on the proposed quasi-isentropic hypothesis, relevant isentropy theories, and the functional relationship between detonation parameters and entropy as well as Al reaction degree, the characteristic lines of aluminized explosives in accelerating flyer plates were theoretically studied, a quasi-isentropic theoretical model for the aluminized explosive driving the flyer plate was built and the calculation methods for the variations of flyer plate velocity, Al reaction degree, and detonation product parameters with time and axial positions were developed. The theoretical model built is verified by the experimental results of the CL-20-based aluminized explosive driving flyer plate. It was found that the model built could accurately calculate the variations of flyer plate velocity and Al reaction degree over time. In addition, how physical parameters including detonation product pressure and temperature varied with time and axial positions was identified. The action time of the positive pressure after the detonation of aluminized explosives was found prolonged and the downtrend of the temperature was slowed down and even reversed to a slight rise due to the aftereffect reaction between the Al powder and the detonation products.展开更多
Afterburning behind the detonation front of an aluminized explosive releases energy on the millisecond timescale,which prolong the release of detonation energy and the energy release at different stages also shows sig...Afterburning behind the detonation front of an aluminized explosive releases energy on the millisecond timescale,which prolong the release of detonation energy and the energy release at different stages also shows significant differences.However,at present,there are few effective methods for evaluating the energy release characteristics of the middle reaction stage of such explosives,which can have a duration of tens to hundreds of microseconds.The present work demonstrates an approach to assessing the midstage of an aluminized explosive detonation based on a water push test employing a high degree of confinement.In this method,the explosive is contained in a steel cylinder having one end closed that is installed at the bottom of a transparent water tank.Upon detonation,the gaseous products expand in one direction while forcing water ahead of them.The resulting underwater shock wave and the interface between the gas phase products and the water are tracked using an ultra-high-speed framing and streak camera.The shock wave velocity in water and the expansion work performed by the gaseous detonation products were calculated to assess the energy release characteristics of aluminized explosives such as CL-20 and RDX in the middle stage of the detonation reaction.During the middle stage of the detonation process of these aluminized explosives,the aluminum reaction reduced the attenuation of shock waves and increased the work performed by gas phase products.A higher aluminum content increased the energy output while the presence of oxidants slowed the energy release rate.This work demonstrates an effective means of evaluating the performance of aluminized explosives.展开更多
This work aims to research the effects on the early responses of the air-backed plate subjected to the loading generated by the underwater explosion with aluminized explosives.The loading characteristics of underwater...This work aims to research the effects on the early responses of the air-backed plate subjected to the loading generated by the underwater explosion with aluminized explosives.The loading characteristics of underwater explosion for ideal explosive(TNT),aluminized explosives(RS211 and RBUL) are obtained experimentally.The tested aluminized explosives have different energy output compared with TNT.Based on the Taylor plate theory,the early responses of the air-backed steel plate affected by the measured loading is analyzed.The analytical results indicate that the pressure curve of the shock wave within 1 time decay constant is the main factor affecting the kick-off velocity of the plate when cavitation occurring.The velocity responses of the plate produced by the loading of RS211 and RBUL are obviously different with that of an equivalent TNT charge,which also indicates validity and suitability should be noticed in the case of substituting TNT for aluminized explosives.Moreover,the uncertainties in the responses of the plate produced by RS211 and RBUL are much larger than TNT.展开更多
A quasi-isentropic study on the process of driving a cylinder with aluminized explosives was carried out to examine the influence of the aluminum(Al) reaction rate on cylinder expansion and the physical parameters of ...A quasi-isentropic study on the process of driving a cylinder with aluminized explosives was carried out to examine the influence of the aluminum(Al) reaction rate on cylinder expansion and the physical parameters of the detonation products. Based on the proposed quasi-isentropic hypothesis and relevant isentropic theories, the characteristic lines of aluminized explosives driving a cylinder were analyzed,and a quasi-isentropic model was established. This model includes the variation of the cylinder wall velocity and the physical parameters of the detonation products with the Al reaction degree. Using previously reported experimental results, the quasi-isentropic model was verified to be applicative and accurate. This model was used to calculate the physical parameters for cylinder experiments with aluminized cyclotrimethylenetrinitramine explosives with 15.0 % and 30.0 % Al content. The results show that this quasi-isentropic model can be used not only to calculate the cylinder expansion rule or Al reaction degree, but also to calculate the physical parameters of the detonation products in the process of cylinder expansion. For explosives with 15.0 % and 30.0 % Al, 24.3 % and 18.5 % of the Al was found to have reacted at 33.9 μs and 34.0 μs, respectively. The difference in Al content results in different reaction intensity, occurrence time, and duration of two forms of reaction(diffusion and kinetic) between the Al powder and the detonation products;the post-detonation burning reaction between the Al powder and the detonation products prolongs the positive pressure action time, resulting in a continuous rise in temperature after detonation.展开更多
Aluminized explosives exhibit excellent performance because the oxidation of aluminum(Al)powders enhances the pressure and temperature of detonation products.However,the equation of state(EOS)of detonation products ha...Aluminized explosives exhibit excellent performance because the oxidation of aluminum(Al)powders enhances the pressure and temperature of detonation products.However,the equation of state(EOS)of detonation products has not been understood well.In the present study,we conducted long-time tests(approximately 1 ms)of a metal rod driven by detonation products of RDX,RDX/Li F,and RDX/Al.In addition,we used laser velocimetry(PDV)to measure the freesurface velocity of the rod.Thermochemical code DLCHEQ was successfully applied to the hydrodynamic program SSS to perform the roddriven test,and a novel method was established to study the EOS of detonation products from the perspective of composition.The reliability of DLCEHQ was validated by a small deviation(<10%)between the experimental rod free-surface velocity of RDX and the calculated results;the deviation was considerably less than that from the results obtained using the JWL EOS and ideal-gas EOS.The endothermic process and the reaction of Al powders(Al+H_(2)O+NO+CO_(2)→CO+H_(2)+N_(2)+Al_(2)O_(3))were analyzed by calculating the rod free-surface velocity of RDX/Li F and RDX/Al,respectively.The results of the present study demonstrated that the thermodynamic state of Al powders has notable influence on the EOS of aluminized detonation products,and the findings were compared with those of previous studies.First,the temperature equilibrium between Al powders and CHNO products is not always achieved,and the disequilibrium is more obvious when the reaction of Al powders is stronger.Second,the reaction rate of Al powders depends on pressure and Al content.Finally,the endothermic process of Al powders has a high contribution to the decrease in the work ability of RDX/Al instead of the gasconsumption mechanism of the Al reaction.More than half of the reaction heat of Al powders is used to heat itself,whereas the gas consumption during the reaction is negligible.展开更多
基金supported by the National Natural Science Foundation of China(NSFC,Grant Nos.11872120,12102050)Key Laboratory of Explosion Science and Technology(Grant No.QNKT22-01).
文摘The new CL-20(hexanitrohexaazaisowurtzitane)type aluminized explosives in the overdrive detonation(ODD)conditions of the core problem is how to accurately represent the state of the overdrive detonation products.To this end,this paper is based on the impedance matching method to test the ODD conditions of CL-20 type aluminium explosive particle velocity.Calculated the interfacial pressure of the shock wave in different media.Determined the characteristic parameters of the reaction zone of the detonation of CL-20 aluminized explosives.Calibrated the parameters of the JoneseWilkinseLee(JWL)+γ equation for the detonation products(DPs).Revealed the effect of different DPs equation of state(EOS)on the Hugoniot pressure of ODD.The results indicate that when the content of aluminum powder ranges from 0%to 30%,the duration of the ODD reaction zone and the width of the detonation reaction zone of the CL-20-based aluminized explosive are directly proportional to the content of aluminum powder.The width of the detonation reaction zone is increased by 1.97 times to 2.7 times compared to that of the reaction zone without the addition of aluminum powder.However,the energy release efficiency of the detonation reaction zone is inversely proportional to the content of aluminum powder.When the aluminum powder content was held constant,the incorporation of AP caused a 25%reduction in the energy release efficiency of the detonation reaction zone.Compared with existing ODD state equations,the JWL +γ equation is superior in calibrating overpressure Hugoniot data and the isentropic expansion in the C-J state.The deviation between calculated pressure results and experimental measurements is within 6%.
基金National Natural Science Foundation of China(Grant No.11872120).
文摘Taking CL-20(Hexanitrohexaazaisowurtzitane)-based aluminized explosives with high gurney energy as the research object, this research experimentally investigates the work capability of different aluminized explosive formulations when driving metal flyer plates in the denotation wave propagation direction.The research results showed that the formulations with 43 μm aluminum(Al) powder particles(The particle sizes of Al powder were in the range of 2~43 μm) exhibited the optimal performance in driving flyer plates along the denotation wave propagation direction. Compared to the formulations with Al powder 13 μm, the formulations with Al powder 2 μm delivered better performance in accelerating metal flyer plates in the early stage, which, however, turned to be poor in the later stage. The CL-20-based explosives containing 25% Al far under-performed those containing 15% Al. Based on the proposed quasi-isentropic hypothesis, relevant isentropy theories, and the functional relationship between detonation parameters and entropy as well as Al reaction degree, the characteristic lines of aluminized explosives in accelerating flyer plates were theoretically studied, a quasi-isentropic theoretical model for the aluminized explosive driving the flyer plate was built and the calculation methods for the variations of flyer plate velocity, Al reaction degree, and detonation product parameters with time and axial positions were developed. The theoretical model built is verified by the experimental results of the CL-20-based aluminized explosive driving flyer plate. It was found that the model built could accurately calculate the variations of flyer plate velocity and Al reaction degree over time. In addition, how physical parameters including detonation product pressure and temperature varied with time and axial positions was identified. The action time of the positive pressure after the detonation of aluminized explosives was found prolonged and the downtrend of the temperature was slowed down and even reversed to a slight rise due to the aftereffect reaction between the Al powder and the detonation products.
基金supported by the National Natural Science Foundation of China(Grant No.11832006)。
文摘Afterburning behind the detonation front of an aluminized explosive releases energy on the millisecond timescale,which prolong the release of detonation energy and the energy release at different stages also shows significant differences.However,at present,there are few effective methods for evaluating the energy release characteristics of the middle reaction stage of such explosives,which can have a duration of tens to hundreds of microseconds.The present work demonstrates an approach to assessing the midstage of an aluminized explosive detonation based on a water push test employing a high degree of confinement.In this method,the explosive is contained in a steel cylinder having one end closed that is installed at the bottom of a transparent water tank.Upon detonation,the gaseous products expand in one direction while forcing water ahead of them.The resulting underwater shock wave and the interface between the gas phase products and the water are tracked using an ultra-high-speed framing and streak camera.The shock wave velocity in water and the expansion work performed by the gaseous detonation products were calculated to assess the energy release characteristics of aluminized explosives such as CL-20 and RDX in the middle stage of the detonation reaction.During the middle stage of the detonation process of these aluminized explosives,the aluminum reaction reduced the attenuation of shock waves and increased the work performed by gas phase products.A higher aluminum content increased the energy output while the presence of oxidants slowed the energy release rate.This work demonstrates an effective means of evaluating the performance of aluminized explosives.
基金This paper is supported by the project of State Key Laboratory of Explosion Science and Technology(Beijing Institute of Technology).The project number is NO.QNKT19-04.
文摘This work aims to research the effects on the early responses of the air-backed plate subjected to the loading generated by the underwater explosion with aluminized explosives.The loading characteristics of underwater explosion for ideal explosive(TNT),aluminized explosives(RS211 and RBUL) are obtained experimentally.The tested aluminized explosives have different energy output compared with TNT.Based on the Taylor plate theory,the early responses of the air-backed steel plate affected by the measured loading is analyzed.The analytical results indicate that the pressure curve of the shock wave within 1 time decay constant is the main factor affecting the kick-off velocity of the plate when cavitation occurring.The velocity responses of the plate produced by the loading of RS211 and RBUL are obviously different with that of an equivalent TNT charge,which also indicates validity and suitability should be noticed in the case of substituting TNT for aluminized explosives.Moreover,the uncertainties in the responses of the plate produced by RS211 and RBUL are much larger than TNT.
基金National Natural Science Foundation of China(Grant No.11872120).
文摘A quasi-isentropic study on the process of driving a cylinder with aluminized explosives was carried out to examine the influence of the aluminum(Al) reaction rate on cylinder expansion and the physical parameters of the detonation products. Based on the proposed quasi-isentropic hypothesis and relevant isentropic theories, the characteristic lines of aluminized explosives driving a cylinder were analyzed,and a quasi-isentropic model was established. This model includes the variation of the cylinder wall velocity and the physical parameters of the detonation products with the Al reaction degree. Using previously reported experimental results, the quasi-isentropic model was verified to be applicative and accurate. This model was used to calculate the physical parameters for cylinder experiments with aluminized cyclotrimethylenetrinitramine explosives with 15.0 % and 30.0 % Al content. The results show that this quasi-isentropic model can be used not only to calculate the cylinder expansion rule or Al reaction degree, but also to calculate the physical parameters of the detonation products in the process of cylinder expansion. For explosives with 15.0 % and 30.0 % Al, 24.3 % and 18.5 % of the Al was found to have reacted at 33.9 μs and 34.0 μs, respectively. The difference in Al content results in different reaction intensity, occurrence time, and duration of two forms of reaction(diffusion and kinetic) between the Al powder and the detonation products;the post-detonation burning reaction between the Al powder and the detonation products prolongs the positive pressure action time, resulting in a continuous rise in temperature after detonation.
基金financial support provided by the National Natural Science Foundation of China(Grant No.11902276)the Natural Science Foundation of Sichuan Province(Grant No.2022NSFSC1802)+2 种基金the National Key Laboratory for Shock Wave and Detonation Physics of China(Grant No.JCKYS2019212007)the Original Scientific Research Instrument and Equipment Development Project of Southwest Jiaotong University(Grant No.XJ2021KJZK055)Sichuan Science and Technology Development Project(Grant No.2021ZYD0027)。
文摘Aluminized explosives exhibit excellent performance because the oxidation of aluminum(Al)powders enhances the pressure and temperature of detonation products.However,the equation of state(EOS)of detonation products has not been understood well.In the present study,we conducted long-time tests(approximately 1 ms)of a metal rod driven by detonation products of RDX,RDX/Li F,and RDX/Al.In addition,we used laser velocimetry(PDV)to measure the freesurface velocity of the rod.Thermochemical code DLCHEQ was successfully applied to the hydrodynamic program SSS to perform the roddriven test,and a novel method was established to study the EOS of detonation products from the perspective of composition.The reliability of DLCEHQ was validated by a small deviation(<10%)between the experimental rod free-surface velocity of RDX and the calculated results;the deviation was considerably less than that from the results obtained using the JWL EOS and ideal-gas EOS.The endothermic process and the reaction of Al powders(Al+H_(2)O+NO+CO_(2)→CO+H_(2)+N_(2)+Al_(2)O_(3))were analyzed by calculating the rod free-surface velocity of RDX/Li F and RDX/Al,respectively.The results of the present study demonstrated that the thermodynamic state of Al powders has notable influence on the EOS of aluminized detonation products,and the findings were compared with those of previous studies.First,the temperature equilibrium between Al powders and CHNO products is not always achieved,and the disequilibrium is more obvious when the reaction of Al powders is stronger.Second,the reaction rate of Al powders depends on pressure and Al content.Finally,the endothermic process of Al powders has a high contribution to the decrease in the work ability of RDX/Al instead of the gasconsumption mechanism of the Al reaction.More than half of the reaction heat of Al powders is used to heat itself,whereas the gas consumption during the reaction is negligible.
