The Measurement System Research Of Spray Image Based On Matlab

Characteristics of the fuel injection and spray affect the power, economy and emissions of engine. And the research of fuel spray characteristics are considerably important for the engine to enhance its performances. The main evaluating indicators of fuel spray characteristics include:spray cone angle, penetration distance, drops diameter size, distribution and so on. In order to study the spray characteristics of diesel alternate fuels such as the biodiesel, the dimethyl ether mixed with diesel oil (D20) and so on, it's necessary to study a highly effective, fast and convenient method to measure each index of spray characteristics.According to the digital image processing technology, the paper uses the MATLAB software to make a program processing reseach on the measurement of spray images. It has been mainly used the digital image processing theory in programming process such as that image type conversion, histogram, image enhancement, image segmentation, mathematical morphology, binary image processing theory and so on. Meanwhile it also has been used the programming internal library functions of MATLAB image processing toolbox.The paper has achieved the measurements of the spray cone angle and the penetration distance of the fuel spray column through programming, and it realizes the programme interface design on the basis of the MATLAB/GUI software platform. In addition, the paper has achieved the optimization design of spray droplet GUI interface procedure. Meanwhile, it has sucessfully compiled the MATLAB program to run independently.The results which has measured a variety of sub-blocks running the spray droplets measuring procedure optimized show that: measurement results are or less compared with the results of artificial read, similar trend in the distribution curve, and are both peak at the 14 microns, which indicated the small particles drop occupying an absolute majority, but it should be noted that sub-block can not be too small.Using the measurement program of fuel spray column, the paper has tested the procedure measuring error scope. The measurement result indicates that the appropriate threshold value coefficient can make the measuring error scope within 5% and especially the error scope of results of the spray penetration distance within 1%, which has fully proved the program is feasible. Finally, the paper has carried on the spray image measurement of the the dimethyl ether mixed with diesel oil (D20), which also obtains the same conclusion as other measurement methods.