Research On The Spatial Distribution Characteristics Of Impingement Spray

Since the first petroleum crisis broke out in the 1970s of the 20^th century, as the main energy-consumption machine, diesel is recognized more and more of its economical efficiency. The environment pollution becomes a big trouble for people because of the using of diesel. The combustion process of diesel directly influence the generation of pollutant. Further, the fuel injection and the establishment of gas mixture are the uppermost factors influencing the combustion process. So the study of spray process is important for optimizing spray and establishment of gas mixture. Visualization is a new method of high technology, which comes into existence recently. With the advantages of directness, high efficiency and high reliability, visualization becomes an important manner for studying diesel spray. And it is the assistant methods for studying fuel injection, the establishment of gas mixture, the design of nozzle and chamber, and its match optimization.Firstly, it introduces the main methods of visualization and sums up the research progress and status combining the relevant documents. Secondly, the whole spray visualization system is designed and machined. The system is made up of spray high-pressure vessel, oil supply system, light path system, image collection and treatment system and control system. The spray visualization tests free spray; flat injection, rut injection, multi-chip injection-cover injection, tapered injection-cover injection and two injection chamber are done. Many valuable original data are obtained and classified to verify the results from simulation calculation.The test results are numerically simulated with AVL fire. The network of calculation is established while the terminal and initial conditions are defined. The basic flowed equation and sub-model of spray calculation are coupled. The three-dimensional numerical simulation calculations of chamber and nozzle impingement process are conducted. The results of calculation and test have good anastigmatic level.The conclusions of comparative test and calculation are as follows: it is favorable to accelerate the mixture process and improve mixture quality with short-distance to impinge and increase the back pressure. Consequently the combustion process is enhanced and the discharge of exhaust is reduced.