Experiment Study Of Viscous Liquid Film Disintegration In A Stationary Air Medium

Combustion process is one of the main questions for discussion in internal-combustion engine nowadays. Combustion process is only effectively controlled in order to essentially improve engine's power, economy and more effectively control exhaust pollution. There is closely relationship between the spray technology and the progress of combustion technology. They promote each other in the progress .So it is necessary to deeply study for spray. The spray and atomization is as one of mechanics'branchs, which is prevalently regarded by the home and abroad. It has been a field of international study. Its development mainly lies in the development of spray maths model, incessant integrity of numerical calculation and analyse, improvement and development of optical testing technology.According to geometry analogical theory, we design and do planar slot nozzle and air-force planar slot nozzle. We establish isobarical spray test-bed, and make testing way. The planar liquid film photoes are taken with EOS30D numerical camera when the spray pressure is 0.2MPa and 0.4MPa. The conclusions which are got by using Photoshop to deal with the pictures and drawing tables compare with the former scholastic studies, in order to furthest improve power, economy and reduce exhaust pollution. The 50 sheets of pictures are picked at every work status to calculate average and draw graph. The disintegration of the water film is main influenced with the velocity under the Rayleigh mode. It has close relationship with Re and We, but has not direct relationship with the spray pressure.For the size of the nozzle which is a small width thick ratio, Rayleigh mode, low velocity spray, the disintegration length of the water film increases with the velocity's increase. It has not direct relationship with the spray pressure. The spray pressure can affect disintegration length by the velocity. That is to say, the velocity is steady factor of water film disintegration. In order to discuss the spray pressure how to affect atomization quality under the Sprays mode, we do the experiment of atomization drop's Sauter mean diameter and size distribution with high, low spray pressure on diesel nozzle spray characteristic experiment table. With the spray pressure minishes, the taper angle becomes small, Sauter mean diameter increases, the peak value of drop size number distribution graph reduces, the graph becomes placid, the cumulation volume distribution graph reduces, the drop size of reaching a certain cumulation volume increases, the big drop increases, the characteristic diameter increases,Δs andΔb become small. The result shows that atomization quality becomes bad when the spray pressure reduces, but the size distribution becomes more well-proportioned.