Simultaneous measurement of particle velocity and size based on gray difference and autocorrelation  

作　　者：Huang ChengJie Wu ZhiJun Li ZhiLong Li LiGuang 

机构地区：[1]Tongji Univ, Sch Automot Studies, Shanghai 200093, Peoples R China [2]Shanghai Jiao Tong Univ, Minist Educ, Key Lab Power Machinery & Engn, Shanghai 200030, Peoples R China

出　　处：《Science China(Technological Sciences)》2010年第10期2833-2838,共6页中国科学（技术科学英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.50676055);sponsored by Shanghai Rising-Star Program(Grant No.07QA1405);supported by Program for New Century Ex-cellent Talents in University(NCET-10-0605)

摘　　要：The gray of two images of a same particle taken by a digital camera with different exposure times is different too. Based on the gray difference of particle images in a double-exposed photo and autocorrelation processing of digital images,this paper proposes a method for measuring particle velocities and sizes simultaneously. This paper also introduces the theoretical foundation of this method,the process of particle imaging and image processing,and the simultaneous measurement of velocity and size of a low speed flow field with 35 μm and 75 μm standard particles. The graphical measurement results can really reflect the flow characteristics of the flow field. In addition,although the measured velocity and size histograms of these two kinds of standard particles are slightly wider than the theoretical ones,they are all still similar to the normal distribution,and the peak velocities and diameters of the histograms are consistent with the default values. Therefore,this measurement method is capable of providing moderate measurement accuracy,and it can be further developed for high-speed flow field measurements.The gray of two images of a same particle taken by a digital camera with different exposure times is different too. Based on the gray difference of particle images in a double-exposed photo and autocorrelation processing of digital images,this paper proposes a method for measuring particle velocities and sizes simultaneously. This paper also introduces the theoretical foundation of this method,the process of particle imaging and image processing,and the simultaneous measurement of velocity and size of a low speed flow field with 35 μm and 75 μm standard particles. The graphical measurement results can really reflect the flow characteristics of the flow field. In addition,although the measured velocity and size histograms of these two kinds of standard particles are slightly wider than the theoretical ones,they are all still similar to the normal distribution,and the peak velocities and diameters of the histograms are consistent with the default values. Therefore,this measurement method is capable of providing moderate measurement accuracy,and it can be further developed for high-speed flow field measurements.

关 键 词：fuel SPRAY PARTICLE velocity and SIZE PARTICLE image GRAY DIFFERENCE exposure time 

分 类 号：TH[机械工程]