In order to improve the detonation characteristics of RDX,a RDX-based composite explosive with TiH_(2)powders was prepared.The effects of content and particle size of TiH_(2)powders on thermal safety,shock wave parame...In order to improve the detonation characteristics of RDX,a RDX-based composite explosive with TiH_(2)powders was prepared.The effects of content and particle size of TiH_(2)powders on thermal safety,shock wave parameters and thermal damage effects of RDX-based composite explosive were studied with the C80 microcalorimeter,air blast experiment system and colorimetric thermometry method.Experimental results showed that TiH_(2)powders could enhance the thermal stability of RDX-based composite explosive and increase its ultimate decomposition heat.The content and particle size of TiH_(2)powders also had significant effects on the thermal safety,detonation velocity,shock wave parameters,fireball temperature and duration of RDX-based composite explosives.Furthermore,the differences of TiH_(2)and Ti powders on the detonation energy output rules of RDX-based composite explosives were also compared,showing that TiH_(2)powders had better influences on improving the explosion power and thermal damage effect of RDX-based composite explosives than Ti powders,for the participation of free H_(2)released by TiH_(2)powders in the detonation process.TiH_(2)powders have important research values as a novel energetic additive in the field of military composite explosives.展开更多
The flame propagation processes of MgH_(2)dust clouds with four different particle sizes were recorded by a high-speed camera.The dynamic flame temperature distributions of MgH_(2)dust clouds were reconstructed by the...The flame propagation processes of MgH_(2)dust clouds with four different particle sizes were recorded by a high-speed camera.The dynamic flame temperature distributions of MgH_(2)dust clouds were reconstructed by the two-color pyrometer technique,and the chemical composition of solid combustion residues were analyzed.The experimental results showed that the average flame propagation velocities of 23μm,40μm,60μm and 103μm MgH_(2)dust clouds in the stable propagation stage were 3.7 m/s,2.8 m/s,2.1 m/s and 0.9 m/s,respectively.The dust clouds with smaller particle sizes had faster flame propagation velocity and stronger oscillation intensity,and their flame temperature distributions were more even and the temperature gradients were smaller.The flame structures of MgH_(2)dust clouds were significantly affected by the particle sinking velocity,and the combustion processes were accompanied by micro-explosion of particles.The falling velocities of 23μm and 40μm MgH_(2)particles were 2.24 cm/s and 6.71 cm/s,respectively.While the falling velocities of 60μm and 103μm MgH_(2)particles were as high as 15.07 cm/s and 44.42 cm/s,respectively,leading to a more rapid downward development and irregular shape of the flame.Furthermore,the dehydrogenation reaction had a significant effect on the combustion performance of MgH_(2)dust.The combustion of H_(2)enhanced the ignition and combustion characteristics of MgH_(2)dust,resulting in a much higher explosion power than the pure Mg dust.The micro-structure characteristics and combustion residues composition analysis of MgH_(2)dust indicated that the combustion control mechanism of MgH_(2)dust flame was mainly the heterogeneous reaction,which was affected by the dehydrogenation reaction.展开更多
In the study,the two-color pyrometer technique was used to measure the transient temperature field of emulsion explosives with different contents of TiH_(2)powders.The experimental results showed that the introduction...In the study,the two-color pyrometer technique was used to measure the transient temperature field of emulsion explosives with different contents of TiH_(2)powders.The experimental results showed that the introduction of TiH_(2)powders could significantly increase the explosion temperature and fireball duration of emulsion explosive.When emulsion explosives were ignited,the average explosion temperature of pure emulsion explosive continuously decreased while emulsion explosives added with TiH_(2)powders increased at first and then decreased.When the content of TiH_(2)powders was 6 mass%,the explosion average temperature reached its maximum value of 3095 K,increasing by 43.7%as compared with that of pure emulsion explosive.In addition,the results of air blast experiment and explosion heat test showed that the variation trends of shock wave parameters,explosion heat and theoretical explosion temperature of emulsion explosives with different contents of TiH_(2)powders were basically consistent with that of explosion temperature measured by the two-color pyrometer technique.In conclusion,the two-color pyrometer technique would be conducive to the formula design of emulsion explosive by understanding the explosion temperature characteristics.展开更多
基金the National Natural Science Foundation of China(Grant Nos.11972046,12272001)the Outstanding Youth Project of Natural Science Foundation of Anhui Province(Grant No.2108085Y02)+1 种基金Anhui University of Science and Technology Postgraduate Innovation Fund(Grant No.2022CX2108)the authors would like to thank these foundations for the financial supports.
文摘In order to improve the detonation characteristics of RDX,a RDX-based composite explosive with TiH_(2)powders was prepared.The effects of content and particle size of TiH_(2)powders on thermal safety,shock wave parameters and thermal damage effects of RDX-based composite explosive were studied with the C80 microcalorimeter,air blast experiment system and colorimetric thermometry method.Experimental results showed that TiH_(2)powders could enhance the thermal stability of RDX-based composite explosive and increase its ultimate decomposition heat.The content and particle size of TiH_(2)powders also had significant effects on the thermal safety,detonation velocity,shock wave parameters,fireball temperature and duration of RDX-based composite explosives.Furthermore,the differences of TiH_(2)and Ti powders on the detonation energy output rules of RDX-based composite explosives were also compared,showing that TiH_(2)powders had better influences on improving the explosion power and thermal damage effect of RDX-based composite explosives than Ti powders,for the participation of free H_(2)released by TiH_(2)powders in the detonation process.TiH_(2)powders have important research values as a novel energetic additive in the field of military composite explosives.
基金supported by the National Natural Science Foundation of China(Grant Nos.12272001,11972046)the Outstanding Youth Project of Natural Science Foundation of Anhui Province(Grant No.2108085Y02)the Major Project of Anhui University Natural Science Foundation(Grant No.KJ2020ZD30)。
文摘The flame propagation processes of MgH_(2)dust clouds with four different particle sizes were recorded by a high-speed camera.The dynamic flame temperature distributions of MgH_(2)dust clouds were reconstructed by the two-color pyrometer technique,and the chemical composition of solid combustion residues were analyzed.The experimental results showed that the average flame propagation velocities of 23μm,40μm,60μm and 103μm MgH_(2)dust clouds in the stable propagation stage were 3.7 m/s,2.8 m/s,2.1 m/s and 0.9 m/s,respectively.The dust clouds with smaller particle sizes had faster flame propagation velocity and stronger oscillation intensity,and their flame temperature distributions were more even and the temperature gradients were smaller.The flame structures of MgH_(2)dust clouds were significantly affected by the particle sinking velocity,and the combustion processes were accompanied by micro-explosion of particles.The falling velocities of 23μm and 40μm MgH_(2)particles were 2.24 cm/s and 6.71 cm/s,respectively.While the falling velocities of 60μm and 103μm MgH_(2)particles were as high as 15.07 cm/s and 44.42 cm/s,respectively,leading to a more rapid downward development and irregular shape of the flame.Furthermore,the dehydrogenation reaction had a significant effect on the combustion performance of MgH_(2)dust.The combustion of H_(2)enhanced the ignition and combustion characteristics of MgH_(2)dust,resulting in a much higher explosion power than the pure Mg dust.The micro-structure characteristics and combustion residues composition analysis of MgH_(2)dust indicated that the combustion control mechanism of MgH_(2)dust flame was mainly the heterogeneous reaction,which was affected by the dehydrogenation reaction.
基金supported by the National Natural Science Foundation of China(No.11972046)Outstanding Youth Project of Natural Science Foundation of Anhui Province(No.2108085Y02)+1 种基金Major Project of Anhui University Natural Science Foundation(No.KJ2020ZD30)Anhui University of Science and Technology Postgraduate Innovation Fund(No.2020CX2066)。
文摘In the study,the two-color pyrometer technique was used to measure the transient temperature field of emulsion explosives with different contents of TiH_(2)powders.The experimental results showed that the introduction of TiH_(2)powders could significantly increase the explosion temperature and fireball duration of emulsion explosive.When emulsion explosives were ignited,the average explosion temperature of pure emulsion explosive continuously decreased while emulsion explosives added with TiH_(2)powders increased at first and then decreased.When the content of TiH_(2)powders was 6 mass%,the explosion average temperature reached its maximum value of 3095 K,increasing by 43.7%as compared with that of pure emulsion explosive.In addition,the results of air blast experiment and explosion heat test showed that the variation trends of shock wave parameters,explosion heat and theoretical explosion temperature of emulsion explosives with different contents of TiH_(2)powders were basically consistent with that of explosion temperature measured by the two-color pyrometer technique.In conclusion,the two-color pyrometer technique would be conducive to the formula design of emulsion explosive by understanding the explosion temperature characteristics.
