单帧长曝光法颗粒测速上限的影响因素  

Influencing Factors of Upper Limit for Particle Velocity Measurement Using Single-Frame Long-Exposure Method

作　　者：冯明亮[1,2] 周骛[1,2] 蔡小舒[1,2] 

机构地区：[1]上海市动力工程多相流动与传热重点实验室,上海200093 [2]上海理工大学颗粒与两相流测量研究所,上海200093

出　　处：《激光与光电子学进展》2017年第5期207-213,共7页Laser & Optoelectronics Progress

基　　金：国家自然科学基金(51576130;51327803);上海市教委资助项目(14CG46);上海市科委科研计划项目(13DZ2260900)

摘　　要：为了提高单帧长曝光图像法的颗粒速度测量的测速上限,以背光成像的单帧长曝光法测速装置为研究对象,从轨迹识别的角度,对该方法测速上限的影响因素进行了理论分析和实验研究。结果表明:在背光成像方式下,颗粒速度越高,轨迹灰度值越高,越难以识别;从轨迹可识别性的角度可知,影响因素主要包括颗粒直径、颗粒透射率和光源光强;当光源光强足够时,背光成像的单帧长曝光法测速装置对直径50μm不透光圆盘颗粒的测速上限为1250m/s。In order to improve the upper limit of particle velocity measurement for single-frame long-exposure imaging method, influence factors of upper limit for velocity measurement are theoretically analyzed and experimentally researched with backlit imaging single-frame long exposure method from the perspective of image grayscale. The results show that for backward illumination, higher particle velocity leads to higher gray value of particle image and more difficult to distinguish it. From the perspective of track recognition, the influencing factors mainly include the particle diameter, the particle transmittance and the intensity of light source. It is found that the upper limit of velocity measurement for the opaque disk particle with the diameter of 50μm reaches 1250 m/s by using the backlit imaging single-frame long exposure method velocity measurement device when the intensity of the light source is high enough.

关 键 词：测量 单帧长曝光图像法 测速上限 灰度 

分 类 号：TK31[动力工程及工程热物理—热能工程]