含能材料的燃烧转爆轰研究

本文综述了近年来在可燃气体、推进剂和炸药内，燃烧转爆轰问题的研究成果。对气、固与混合相含能材料的燃烧转爆轰机制、理论研究方法以及目前还存在的问题，作了较系统的介绍与探讨。     

Turbulent explosion characteristics of stoichiometric syngas

In the present article, series of experiments were conducted to investigate turbulent explosion characteristics of stoichiometric syngas (with different hydrogen concentrations, 10%‐90% in volume fraction) in a 28.73‐L spherical turbulent premixed explosion system. The evolution of explosion pressure was recorded in different turbulent environment (with different turbulent intensity, 0.100‐1.309 m/s in root mean square value of velocity fluctuation). From the explosion pressure historic curves, the maximum pressure, lag duration, and explosion duration were obtained; the pressure rise rate and fast burn duration were derived; and deflagration index could be further calculated. The interaction effects of turbulent intensity and hydrogen addition on those explosion parameters were systematically analysed and discussed. Based on the results, an empirical formula about deflagration index of stoichiometric syngas was established.     

Fe2O3-Al纳米铝热剂与超细RDX复合物的制备与性能

采用溶胶-凝胶方法,制备出了纳米铝热剂nano-Fe2O3-Al,并获得了其与超细RDX的复合含能材料nanoFe2O3-Al/SFRDX。采用BET法、SEM、XRD综合表征了nano-Fe2O3-Al的结构,采用TG/DSC联用技术测试了nano-Fe2O3-Al的热性能,结果表明气凝胶铝热剂的反应温度更低;nano-Fe2O3-Al的静电火花感度测试结果表明纳米铝热剂对静电十分敏感。对nano-Fe2O3-Al/SFRDX在无约束条件和密闭条件下的燃烧行为进行了研究,高速相机照片法发现在无约束条件下,nanoFe2O3-Al燃烧高达300 m/s,且nano-Fe2O3-Al/SFRDX具有在无约束条件下由燃烧转为爆轰的趋势。     

含90°直角弯管结构受限空间油气泄压爆炸实验与大涡模拟研究

针对含90°直角弯管结构受限空间油气泄压爆炸特性进行了研究,采用高速摄影等技术对爆炸过程中的压力瞬变、火焰形态进行了采集,同时对实验进行了大涡模拟,精确模拟了火焰经过弯管时的超压特性、流场结构以及火焰形态,并与实验结果进行了对比分析。结果表明：（1）弯管结构对于爆炸过程中火焰结构有影响,在受限空间内火焰形态发生“半球形-指尖形-毛刷状”三种形态转变。（2）在弯管处形成的毛刷状火焰是由弯管局部压力梯度形成的涡流导致的。（3）衍射波与反射波在弯管处的叠加对爆炸超压峰值具有强化作用。（4）爆炸过程中,爆炸超压峰值、火焰速度、火焰锋面面积表现出显著的耦合性,具有密切的内在联系,三者随时间变化趋势存在较强的一致性。     

小尺度受限空间内瓦斯爆燃的动态特性

为获得包括瓦斯爆燃点火初期、火焰加速、减速及二次加速过程中动态火焰微细结构及其与超压之间的相互关系,实验研究了小尺度受限空间内瓦斯爆燃火焰形状、火焰锋面位置、火焰速度及超压等动态特性.研究结果表明,在无障碍物条件下,火焰锋面光滑,火焰形状由"半球"状逐渐演变为"手指"状;而有障碍物条件下,火焰锋面出现明显褶皱和湍流现象,其火焰速度经历两次加速和一次减速过程,最大火焰速度达112m/s,与无障碍物条件下最大值相比增幅为124%;当火焰锋面经过障碍物后即将重新汇合时,出现8.5kPa的最大超压,与无障碍物条件下的最大值相比增幅为118%.     

Formation of carbon clusters in deflagration and detonation waves in gas mixtures

Numerical and experimental results of studying the formation of carbon clusters due to propagation of deflagration and detonation waves in enriched acetylene-oxygen and acetylene-air mixtures are described. Experiments are performed in tubes of different diameters (including tubes filled by a porous medium) with wide-range variations of the initial pressure and the fuel-to-oxidizer ratio. A large variety of carbon clusters formed in different regimes of burning of the mixture is found. A typical size of condensed carbon particles is 15–100 nm. In the case of detonation in a porous medium, the size of carbon particles is 15–45 nm; in some tests, large individual fullerene-type particles 150, 400, and 950 nm in size are formed. The fraction of condensed carbon in the total amount of carbon in the initial mixture is found to depend on the wave type; detonation is characterized by the minimum “yield” of condensed carbon. The amount of condensed carbon increases with increasing acetylene concentration in the mixture and initial pressure. The size of carbon particles in the case of deflagration is greater than that in the case of detonation. Cooling of reaction products decelerates condensation and interrupts the growth of carbon particles. __________ Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 3, pp. 81–94, May–June, 2008.     

正压直吹式制粉系统爆燃分析及对策

直吹式制粉系统燃用高挥发分烟煤时,易发生爆燃事故,通过一次磨煤机爆燃事故的分析,找出爆燃原因,并采取相应措施,为类似情况提供借鉴。     

气体爆燃向爆轰转捩的理论分析

本文在实验的基础上,对瓦斯爆炸过程中爆燃向爆轰转捩(DDT,Deflagration to Detonation Transition)问题进行了研究,并运用CJ(Chapman and Jouguet)理论计算了火焰阵面流场参数。研究结果表明:障碍物对瓦斯爆炸过程中爆燃向爆轰转捩具有诱导作用,无障碍物时爆炸波的传播速度较小,爆炸强度较弱;随着障碍物的增多,爆炸波和火焰传播速度明显增大,爆燃易于向爆轰转捩,爆炸强度和危险性显著提高。上述研究结果对于现场如何防治瓦斯爆炸,防止、降低煤矿重大事故的发生具有一定的指导作用。     

气体爆燃向爆轰转捩的理论分析（增刊）

本文在实验的基础上,对瓦斯爆炸过程中爆燃向爆轰转捩(DDT, Deflagration to Detonation Transition)问题进行了研究,并运用CJ(Chapman and Jouguet)理论计算了火焰阵面流场参数。研究结果表明：障碍物对瓦斯爆炸过程中爆燃向爆轰转捩具有诱导作用,无障碍物时爆炸波的传播速度较小,爆炸强度较弱;随着障碍物的增多,爆炸波和火焰传播速度明显增大,爆燃易于向爆轰转捩,爆炸强度和危险性显著提高。上述研究结果对于现场如何防治瓦斯爆炸,防止、降低煤矿重大事故的发生具有一定的指导作用。