Predictions of extreme near-field blast wave for cylindrical charge is crucial for designing sympathetic detonation protection structures,yet the quantitative analysis of detonation products and shock wave field are s...Predictions of extreme near-field blast wave for cylindrical charge is crucial for designing sympathetic detonation protection structures,yet the quantitative analysis of detonation products and shock wave field are still insufficient.The present work conducted experiments and numerical simulations of nearfield explosion for kilogram scale cylindrical charge,and investigated the propagation and spatial distribution characteristics of incident and reflected blast waves.The results show that near-field reflected overpressure exhibits multi-peak structures,which are primarily governed by reflections of detonation products and shock wave.The reflected peak overpressure dominated by detonation products shows higher sensitivity to scaled distance.Meanwhile,the Rayleigh-Taylor instability(RTI)effect induces the evolutions of detonation products and shock wave interface from smooth to random microjets,increasing dispersion of secondary re flected peak overpressure.In free-field explosion,the incident peak overpressure exhibits a dual-peak structure,governed by the shock wave front and detonation products flowing past the gauge points.The incident peak overpressure dominated by detonation products is sensitive to orientations due to the charge structures.As the aspect ratio of charge increases from 0.6 to 8,the dominant radial azimuth angle region expands from 60°-90°to 30°-90°.An empirical model was developed to predict the spatial distributions of incident peak loads at arbitrary orientations for cylindrical charge with 0.6≤L/D≤8.0 and 0.06 m·kg^(-1/3)展开更多
在城市轨道交通系统中,列车的冲击性负荷严重威胁供电安全,且光伏新能源高效消纳也面临挑战。为此,该研究提出一种光伏发电支持的超级电容器混合储能系统(photovoltaic-hybrid energy storage system,PV-HESS)动态功率自洽策略。该策略...在城市轨道交通系统中,列车的冲击性负荷严重威胁供电安全,且光伏新能源高效消纳也面临挑战。为此,该研究提出一种光伏发电支持的超级电容器混合储能系统(photovoltaic-hybrid energy storage system,PV-HESS)动态功率自洽策略。该策略通过引入功率微分阈值k作为系统的动作信号,实时监测列车运行中的功率变化。当功率变化率超过设定阈值时,系统迅速响应,超级电容器释放能量以平抑尖峰负荷。为验证该策略的有效性,构建了仿真模型,并针对不同工况下的微分阈值k进行了仿真分析。结果表明,当微分阈值k设置为2.4 MW/h时,PV-HESS系统能够快速响应,最大动态功率自洽率提高到15.9%,显著降低了尖峰负荷对地铁供电系统的影响。展开更多
基金supported by the National Natural Science Foundation of China(No.12172051,12172050,12141201,and 12221002)。
文摘Predictions of extreme near-field blast wave for cylindrical charge is crucial for designing sympathetic detonation protection structures,yet the quantitative analysis of detonation products and shock wave field are still insufficient.The present work conducted experiments and numerical simulations of nearfield explosion for kilogram scale cylindrical charge,and investigated the propagation and spatial distribution characteristics of incident and reflected blast waves.The results show that near-field reflected overpressure exhibits multi-peak structures,which are primarily governed by reflections of detonation products and shock wave.The reflected peak overpressure dominated by detonation products shows higher sensitivity to scaled distance.Meanwhile,the Rayleigh-Taylor instability(RTI)effect induces the evolutions of detonation products and shock wave interface from smooth to random microjets,increasing dispersion of secondary re flected peak overpressure.In free-field explosion,the incident peak overpressure exhibits a dual-peak structure,governed by the shock wave front and detonation products flowing past the gauge points.The incident peak overpressure dominated by detonation products is sensitive to orientations due to the charge structures.As the aspect ratio of charge increases from 0.6 to 8,the dominant radial azimuth angle region expands from 60°-90°to 30°-90°.An empirical model was developed to predict the spatial distributions of incident peak loads at arbitrary orientations for cylindrical charge with 0.6≤L/D≤8.0 and 0.06 m·kg^(-1/3)
文摘在城市轨道交通系统中,列车的冲击性负荷严重威胁供电安全,且光伏新能源高效消纳也面临挑战。为此,该研究提出一种光伏发电支持的超级电容器混合储能系统(photovoltaic-hybrid energy storage system,PV-HESS)动态功率自洽策略。该策略通过引入功率微分阈值k作为系统的动作信号,实时监测列车运行中的功率变化。当功率变化率超过设定阈值时,系统迅速响应,超级电容器释放能量以平抑尖峰负荷。为验证该策略的有效性,构建了仿真模型,并针对不同工况下的微分阈值k进行了仿真分析。结果表明,当微分阈值k设置为2.4 MW/h时,PV-HESS系统能够快速响应,最大动态功率自洽率提高到15.9%,显著降低了尖峰负荷对地铁供电系统的影响。
