针对杆式爆炸成型侵彻体(Explosively formed penetrator, EFP)的侵彻能力问题,利用数值仿真手段开展杆式EFP侵彻特性研究,分析杆式EFP成型形态、着靶速度及材料特性对其侵彻能力的影响,得到杆式EFP成型特征参数在侵彻过程中的影响规律...针对杆式爆炸成型侵彻体(Explosively formed penetrator, EFP)的侵彻能力问题,利用数值仿真手段开展杆式EFP侵彻特性研究,分析杆式EFP成型形态、着靶速度及材料特性对其侵彻能力的影响,得到杆式EFP成型特征参数在侵彻过程中的影响规律。研究结果表明:杆式EFP在侵彻过程中,除初始阶段(碰撞后)和最后阶段(杆侵蚀后)外,弹体保持恒定速度运动,满足恒速杆假设;稳定侵彻时,随着密实部长度的逐渐减小,中空尾裙部材料不断流入密实部补充其侵蚀损失。增加弹体长度可以在一定程度上提高EFP的侵彻能力,但归一化侵彻深度下降;提高着靶速度和密实部长度可以显著提升杆式EFP侵彻性能。杆式EFP的强度对侵彻的影响有限,但靶体强度不可忽略,弹靶材料密度是影响侵彻体侵彻的主要因素。展开更多
The killing and injury effects of gas explosion shock wave on mouse in an open space pipeline is tested experimentally. When the methane volume fraction is 10M, the maximum explosion pressure is 0. 264 MPa and the inj...The killing and injury effects of gas explosion shock wave on mouse in an open space pipeline is tested experimentally. When the methane volume fraction is 10M, the maximum explosion pressure is 0. 264 MPa and the injury is the most serious. Specially, some designed obstacles put in the open space pipeline are conducive to producing more stronger gas explosion shock wave. Accordingly, the injury effect of methane explosion on mouse is enhanced under obstacles condition. When the methane volume fraction is 10%, the maximum explosion pressure can reach 0. 298 MPa under obstacles conditiorL It can be concluded that to reduce explosive accident impact, the obstacles in coal mine should be avoided. With the explosions increasing, the death pressure of mouse decreases.展开更多
Combustible gases in coal mines are composed of methane, hydrogen, some multi-carbon alkane gases and other gases. Based on a numerical calculation, the explosion limits of combustible gases were studied, showing that...Combustible gases in coal mines are composed of methane, hydrogen, some multi-carbon alkane gases and other gases. Based on a numerical calculation, the explosion limits of combustible gases were studied, showing that these limits are related to the concentrations of different components in the mixture. With an increase of C4H10 and C6H14, the Lower ExplosionLimit （LEL） and Upper Explosion-Limit （UEL） of a combustible gas mixture will decrease clearly. For every 0.1% increase in C4H10 and C6H14, the LEL decreases by about 0.19% and the UEL by about 0.3%. The results also prove that, by increasing the amount of H2, the UEL of a combustible gas mixture will increase considerably. If the level of HE increases by 0.1%, the UEL will increase by about 0.3%. However, H2 has only a small effect on the LEL of the combustible gas mixture. Our study provides a theoretical foundation for judging the explosion risk of an explosive gas mixture in mines.展开更多
The explosive gases CO and C2H4, released mainly flammable gases during the process of coal self-ignition, are of the most important ingredients of the multi-component gases in goal areas, along with CH4. We have dete...The explosive gases CO and C2H4, released mainly flammable gases during the process of coal self-ignition, are of the most important ingredients of the multi-component gases in goal areas, along with CH4. We have determined some of the parame- ters of explosive properties of the one-component gases CH4, CO and C2H4 using an explosive trial device of polybasic explosive gas mixtures and emphasized particularly the effect on the limits of explosive concentration of the binary explosive mixed gases CH4＋CO, CH4＋C2H4, as a function of the amount of CO, C2H4 and inert flame resisting gases （N2, CO2）. The experimental results show that the effect of inert gases on the explosive limits of mixed gases, given the property of explosive gas, is obvious： the inert gases （N2, CO2） possess some inhibitory effects on the explosion of the multi-component explosive gas mixtures. The results will provide some experimental support to suppress the occurrence of the gas explosions in goaf areas and provide some directions for designing explosion-proof electric equipment and fire arresters.展开更多
文摘针对杆式爆炸成型侵彻体(Explosively formed penetrator, EFP)的侵彻能力问题,利用数值仿真手段开展杆式EFP侵彻特性研究,分析杆式EFP成型形态、着靶速度及材料特性对其侵彻能力的影响,得到杆式EFP成型特征参数在侵彻过程中的影响规律。研究结果表明:杆式EFP在侵彻过程中,除初始阶段(碰撞后)和最后阶段(杆侵蚀后)外,弹体保持恒定速度运动,满足恒速杆假设;稳定侵彻时,随着密实部长度的逐渐减小,中空尾裙部材料不断流入密实部补充其侵蚀损失。增加弹体长度可以在一定程度上提高EFP的侵彻能力,但归一化侵彻深度下降;提高着靶速度和密实部长度可以显著提升杆式EFP侵彻性能。杆式EFP的强度对侵彻的影响有限,但靶体强度不可忽略,弹靶材料密度是影响侵彻体侵彻的主要因素。
文摘The killing and injury effects of gas explosion shock wave on mouse in an open space pipeline is tested experimentally. When the methane volume fraction is 10M, the maximum explosion pressure is 0. 264 MPa and the injury is the most serious. Specially, some designed obstacles put in the open space pipeline are conducive to producing more stronger gas explosion shock wave. Accordingly, the injury effect of methane explosion on mouse is enhanced under obstacles condition. When the methane volume fraction is 10%, the maximum explosion pressure can reach 0. 298 MPa under obstacles conditiorL It can be concluded that to reduce explosive accident impact, the obstacles in coal mine should be avoided. With the explosions increasing, the death pressure of mouse decreases.
基金Projects 706029 supported by the Cultivation Fund of the Key Scientific and Technical Innovation Project of Ministry of Education of China2007AA04Z332 by the National High Technology Research and Development Program of China
文摘Combustible gases in coal mines are composed of methane, hydrogen, some multi-carbon alkane gases and other gases. Based on a numerical calculation, the explosion limits of combustible gases were studied, showing that these limits are related to the concentrations of different components in the mixture. With an increase of C4H10 and C6H14, the Lower ExplosionLimit （LEL） and Upper Explosion-Limit （UEL） of a combustible gas mixture will decrease clearly. For every 0.1% increase in C4H10 and C6H14, the LEL decreases by about 0.19% and the UEL by about 0.3%. The results also prove that, by increasing the amount of H2, the UEL of a combustible gas mixture will increase considerably. If the level of HE increases by 0.1%, the UEL will increase by about 0.3%. However, H2 has only a small effect on the LEL of the combustible gas mixture. Our study provides a theoretical foundation for judging the explosion risk of an explosive gas mixture in mines.
基金The financial supports from the National Natural Science Foundation of China (No.50874088)the Changjiang Scholars and Innovative Research Team in University (No.IRT0856)
文摘The explosive gases CO and C2H4, released mainly flammable gases during the process of coal self-ignition, are of the most important ingredients of the multi-component gases in goal areas, along with CH4. We have determined some of the parame- ters of explosive properties of the one-component gases CH4, CO and C2H4 using an explosive trial device of polybasic explosive gas mixtures and emphasized particularly the effect on the limits of explosive concentration of the binary explosive mixed gases CH4＋CO, CH4＋C2H4, as a function of the amount of CO, C2H4 and inert flame resisting gases （N2, CO2）. The experimental results show that the effect of inert gases on the explosive limits of mixed gases, given the property of explosive gas, is obvious： the inert gases （N2, CO2） possess some inhibitory effects on the explosion of the multi-component explosive gas mixtures. The results will provide some experimental support to suppress the occurrence of the gas explosions in goaf areas and provide some directions for designing explosion-proof electric equipment and fire arresters.
