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The Measurement Of Liquid Diffusion Coefficient By Extracting Features Of Diffusive Image In Real Time

Posted on:2016-09-13Degree:MasterType:Thesis
Country:ChinaCandidate:R F YangFull Text:PDF
GTID:2308330470956126Subject:Optics
Abstract/Summary:PDF Full Text Request
Diffusion coefficient is the study of mass transfer process, computational mass transfer rate and a fatal factor in the design and development of chemical industry. The calculation of the diffusion coefficient, especially the liquid diffusion coefficient is difficult to accomplish due to the structural particularity of liquid molecules and the irregularity of the motion. So far, the liquid diffusion coefficient of different systems is mainly obtained by experiment. At present, the experiment on measuring liquid diffusion coefficient mainly through indirect measuring the concentration of the solution formed by diffusion process with the distribution of space and time, according to describe the diffusion process of Fick’s law to calculate the liquid diffusion coefficient. Using spatial resolution of asymmetric liquid-core cylindrical lens imaging method to measure the liquid diffusion coefficient has the characteristics of quickly speed, good stability measuring system. But in the actual experiment, especially in intuitive observation of obtaining diffusional image’s information, often there are some problems, for example, strong subjective arbitrariness, obtaining information slowly. The image processing technology is can objectively and quickly reflect the image information. In recently years, with the development of digital computer, digital image processing technology has been got development rapidly and extensive use. In the paper, the digital image processing technology is combined with imaging method through the image acquisition system comes with the SDK examples to develop the image acquisition system secondary. According to this way, we build a real time optical image feature extraction system to measure the diffusion coefficient. Using the system to extract the diffusional image feature, to storage experiment data and calculate the liquid diffusion coefficient automatically.Firstly, through a large number of literatures reading, we introduced the liquid diffusion coefficient of the research background and significance. Designed and developed a software to measure liquid diffusion coefficient, the software using real time of the optical image feature extraction method to deal with the image and measure liquid diffusion coefficient can save experimental time, greatly reduce the error caused by man-made subjective judgment factors. The method realizes the measurement automatically. The software on the basis of imaging method of measuring liquid diffusion coefficients of image features, adopt the brightness feature and width feature extraction method to deal with the diffusion coefficient image and obtain the target information and converse of liquid diffusion coefficient. In order to verify the system’s reliability experiment, we used the software to measure the diffusion process of ethylene glycol(EG) in pure water, and we measured the diffusion coefficient is D=1.164×10-5cm2/s, which relative error paralleled with the reference value (D=1.16×10-5cm2/s) is0.34%, under the condition of the room temperature at25℃. The method of diffusion coefficient for chemical engineering research provides an accurate and rapid measuring means.
Keywords/Search Tags:Optical image, Real time processing, Feature extraction, Brightness feature, Width feature
PDF Full Text Request
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