容弹内片状无烟煤粉喷射掺混特性实验研究  

Experimental Study on Injection and Mixing Characteristics of Flake Anthracite Pulverized Coal Within Constant Volume Bomb

作　　者：张锋 续晗 翁春生[1] 罗永晨 肖博文 倪晓冬 郑权[1] ZHANG Feng;XU Han;WENG Chunsheng;LUO Yongchen;XIAO Bowen;NI Xiaodong;ZHENG Quan(National Key Laboratory of Transient Physics,Nanjing University of Science and Technology,Nanjing 210094,China)

机构地区：[1]南京理工大学瞬态物理国家重点实验室,江苏南京210094

出　　处：《弹道学报》2024年第1期41-49,共9页Journal of Ballistics

摘　　要：粉末在容弹以及发动机燃烧室内的掺混状态对粉末爆轰特性有较大的影响,因此亟须对粉末在有限空间内的喷射掺混特性展开研究。搭建了一套透明的容弹系统,通过高速摄影监测系统,对片状煤粉在容弹内的喷射掺混过程进行观测,并对高速摄影拍摄图片进行后处理,分析煤粉在容弹内的喷射掺混变化规律。针对煤粉喷射掺混图像建立了一种灰度值标准差曲率分析方法,研究发现标准差曲率趋于0的初始时刻为煤粉掺混均匀最佳时刻,可以选取为最佳点火时间点,且该方法所选取的时刻与逐帧分析高速摄影图像所选取的时刻吻合。在煤粉浓度为120 g/m^(3),210 g/m^(3),300 g/m^(3)下,依次展开煤粉喷射掺混实验,并应用此灰度图像标准差曲率分析方法进行分析。实验结果表明:保持煤粉浓度一致时,掺混均匀性最佳时间随喷粉时长的增长而逐渐缩短,点火时刻提前;保持喷粉时长一致时,掺混均匀性最佳时间随供粉浓度的增长而延长,点火时刻延后。The mixing state of the powder in the constant volume bomb and the engine combustion chamber has a large impact on the powder detonation characteristics,so it is urgent to study the injection and mixing characteristics of the powder in a limited space,which helps to decide the appropriate ignition time for two-phase detonation.A constant-volume bomb system was built to observe the blending process of the flake anthracite pulverized coal in the constant-volume bomb through a high-speed photographic monitoring system,and post-process of the high-speed photographic images was carried out,and the change of pulverized coal blending in the constant-volume bomb was analyzed.A method for analyzing the curvature of the standard deviation of the gray value was established for the pulverized coal injection blending images.The initial moment when the curvature of standard deviation tends to zero is the best moment for the uniform mixing of pulverized coal,which can be selected as the best ignition time point,and the moment decided by this method coincides with the moment decided by the frame-by-frame analysis of the high-speed photographic images.The experiments were carried out at pulverized coal concentrations of 120 g/m^(3),210 g/m^(3)and 300 g/m^(3),and the standard deviation curvature analysis method of grayscale image was used to analyze.The experimental results show that,while keeping the pulverized coal concentration constant,the well-mixed time decreases with the increase of the powder blowing time,and thus the ignition moment should be advanced;while keeping the powder blowing time constant,the well-mixed time increases with the increase of powder supply concentration,and thus the ignition moment should be delayed.

关 键 词：粉末爆轰发动机 多相流 两相爆轰 喷射掺混 煤粉 定容燃烧弹 

分 类 号：O359[理学—流体力学]