Research On Spray Image Processing Based On Matlab/GUI

Fuel injection and spray features affect the power, economy and emissions of engine. Engine combustion's good or not depends largely on the spray quality of the mixed fuel. The size of the fuel drops is controlled not only by the liquid fragmentation but also by the evaporation and collision of the drops. The evaporation and collision of the drops may result in drop numbers' reduction, the average diameter's fluctuation and drop diameters' redistribution. In order to master diesel spray characteristics of bio-diesel and optimize the usage of bio-diesel technology, the paper studies diesel - bio-diesel mixed fuel spray characteristics.The primary problem of the application of the biodiesel on diesel engine is the biodiesel mixed ratio optimization and combustion organization. The test use vehicle Iveco engine injector and the high-resolution digital imaging technology to make the comparison test of spray droplet size distribution under five kinds of fuel of different mixing ratio to grasp the details of biodiesel-diesel mixed fuel spray features. The result shows that, with the increase of biodiesel mixed ratio, the fuel viscosity was increase, the spray angle was decreased, and the Sauter mean diameter was increased. Compared with pure diesel, MB24 is slightly smaller than the Sauter mean diameter. Spray quality was improved evidently. It could be seen by the droplet size number distribution that all fuel curve peak was located at 14, that was so say, the smaller size droplet took a large percentage. All the curve peaks of droplet size number distribution went down evenly and gently with the increase of biodiesel mixing ratio, which indicated that the fuel droplet size number distribution in spray became even with the increase of fuel viscosity. The diameter of the droplet that reached a certain cumulative volume increased with the increase of biodiesel mixing ration, which indicated that the number of large drops increased.The paper designs the Diesel - Biodiesel mixed fuel spray particles counting system procedures by MATLAB/GUI software to achieve a visual interface to operate. Take the 100B04 photos as example, the paper runs the four program 16 equal, 32 equal, 64 and 128 equal respectively. Using Gaussian low-pass filter for noise reduction processing, using OSTU for the selection of threshold value of the image, the particle distribution curve of the whole image can be acquired.The result compared with the artificial results and theoretical calculation results shows that the three curves goes the same. The paper makes a comparision between the four programs' total particles number and gives out the best program.