毫米级光滑圆管内爆轰波起爆距离实验研究  

The Deflagration-to-Detonation Transition Run-up Distance in Millimeter-scale Smooth Tubes Filled with Propane/Oxygen Mixture

作　　者：陆元刚 杨怀远 张彭岗[1] 潘振华[1] LU Yuan-gang;YANG Huai-yuan;ZHANG Peng-gang;PAN Zhen-hua(Energy and Power Engineering,Jiangsu University,Zhenjiang 212013,China)

机构地区：[1]江苏大学能源与动力工程学院,镇江212013

出　　处：《科学技术与工程》2020年第25期10275-10279,共5页Science Technology and Engineering

基　　金：国家自然科学基金(51876084);天津大学内燃机国家重点实验室基金。

摘　　要：由于在脉冲爆轰发动机进口端设置微孔可有效促进爆轰起爆,故通过高速相机拍摄在初始压力为10~100 kPa下等当量比丙烷/氧气的火焰传播过程研究了毫米级圆管中缓燃向爆轰转捩(deflagration to detonation transition,DDT)距离,实验在长为1930 mm、管径分别为0.5、1、2、4 mm的管道中进行。实验结果表明:面积发散效应导致DDT距离与管径和初始压力不同的变化关系,当初压低于60 kPa时,DDT距离与管径呈线性关系;而当初压在60 kPa以上时,DDT距离在100~200 mm,随管径的变化并不明显。而在同一管径下,DDT距离随初始压力的增大而减小且呈现反比关系,这与大尺度下DDT距离与初压的关系相似。最后,通过讨论边界层厚度对DDT距离的影响得到区分大小尺度DDT模式的临界值。Setting millimeter-scale holes at the close end of combustor of a pulse detonation engine can significantly promote the onset of a detonation wave.Therefore,the deflagration-to-detonation transition(DDT)run-up distance(L DDT)of propane+oxygen(C 3H 8+5O 2)mixtures in various capillary tubes at initial pressure range from 10 to 101.3 kPa was investigated experimentally and recorded with the high-speed digital.Four different diameters of the holes(0.5,1.0,2.0,and 4.0 mm;d)were tested,and the length was 1930 mm.The results indicate that the area divergence caused different relationship between the run-up distance and the initial pressure or the tube diameter in the capillary tubes.The run-up distance could be expressed as linear relationship with d at the lower pressure less than 60 kPa.However,a relatively stable variation range of L DDT was found to be 100~200 mm when initial pressure was greater than 60 kPa.Since the relative distance(L DDT/d)in the capillary tubes was bigger than that in macro-tube,a formula used to predict L DDT/d in macro-tube could not be applied in the micro-tube.For a given tube diameter,the run-up distance could be expressed in a inverse relationship with the initial pressure in both capillary and macro-tubes.Finally,the critical value used for discriminating the DDT model in micro-and macro-tube could be obtained by studying the effect of boundary layer thickness on DDT run-up distance.

关 键 词：毫米级管道 丙烷/氧气 缓燃向爆轰转捩 DDT距离 边界层 

分 类 号：TJ011.1[兵器科学与技术—兵器发射理论与技术]