电工技术学报2025，Vol.40Issue(21)：6780-6794,15.DOI:10.19595/j.cnki.1000-6753.tces.250164
有限空间电爆炸等离子体致裂效应与有机玻璃破片驱动特性
Characteristics of Cracking Effect and PMMA Fragment Driving in Limited Space Electric Explosion
摘要
Abstract
High-power pulsed discharge serves as a critical laboratory tool for emulating blast effects and as an efficient route for scaled validation of novel principles,structures,and materials while capturing fine-scale physical characteristics of explosion loads.To harness the high energy density of electric explosions,confinement is mandatory.When a thin,brittle shell is applied,the resulting fragment cloud exhibits high number density and significant engineering value.Nevertheless,existing investigations of electric explosions in confined spaces have focused primarily on fracture evolution,leaving fragment dynamics largely unexplored.In response,a light-electric joint diagnostic system with spatiotemporal resolution is developed,and a confined electric-explosion source is designed.Polymethyl methacrylate(PMMA)tubes of varying internal diameter constrain metal wires,enabling a systematic comparison of plasma behavior under different degrees of confinement and of the transient force-thermal loading that drives wall fragmentation and fragment acceleration. The influence of discharge energy and tube diameter on electrical characteristics is examined first.With a fixed internal diameter,increasing the charging voltage from 9 kV to 12.9 kV shifts the discharge regime from aperiodic to oscillatory.The peak electric power rises from 109.6 MW to 311.8 MW,an increase of 184%,and the time to peak advances by 30%.Further elevation to 15.8 kV introduces a double-peaked current waveform.At constant stored energy,enlarging the tube diameter from 5.9 mm to 11.9 mm exerts a negligible influence on electrical behavior,presumably because even the smallest diameter(5.9 mm)is an order of magnitude larger than the wire diameter(hundreds of micrometers)and therefore does not significantly perturb energy deposition. The fracture process and fragment velocity and size are analyzed next.Except under the critical condition,complete crack development required 14～18 μs from discharge initiation.Under the critical condition,this duration extends to 27 μs,effectively doubling the fracture time.Crack propagation velocity is approximately 2.5 km/s.After complete wall fragmentation,the initial stored energy governs whether the early expansion resembles a large-fragment burst or a quasi-spherical explosion.Under condition A,fragment velocity rises from 148 m/s to 165 m/s within 30 μs.Under condition B,the peak velocity is only 63 m/s,followed by a prolonged plateau.When the initial stored energy increases from 250 J to 500 J,the maximum fragment size decreases from 32 mm to 11 mm and large fragments become markedly less numerous.At 500 J,reducing the tube diameter from 11.9 mm to 5.9 mm stepwise increases the proportion of fragments in the 0～4 mm range from 47%to 57%,69%and 94%. The wall-damage mechanism is discussed in the final section.Within 5 μs after ignition,the luminous plasma fills the entire tube(inner diameter 10.0 mm,outer diameter 14.0 mm),with the shock front and explosion products indistinguishable.The interaction is interpreted as direct impact of the arc channel on the wall.Calculated arc-channel pressures of 100～110 MPa at 5 μs are consistent with experimental observations,indicating that the channel has approached the inner wall by that instant.关键词
金属丝电爆炸/冲击波/等离子体/聚合物破片Key words
Electrical wire explosion/shock waves/plasmas/polymer fragments分类
动力与电气工程引用本文复制引用
马裕良,吴瑾昊,马颖,鲜欣轩,韩若愚..有限空间电爆炸等离子体致裂效应与有机玻璃破片驱动特性[J].电工技术学报,2025,40(21):6780-6794,15.基金项目
国家自然科学基金(52277134)、北京市自然科学基金(L252044)、中国气象局雷电重点开放实验室开放课题(2024KELL-B004)和中国科协青年人才托举工程(2022QNRC001)资助项目. （52277134）
