三旋流雾化装置中预燃级喷雾特性的实验研究

To investigate the spray characteristics of pilot stage in triple swirling staged combustor in depth，using kerosene，atomization characteristics of pilot stage in a triple swirling atomizer were experimentally investigated which is near the lean blowout condition. The whole spray field and near field region spray in the downstream of atomizer were investigated and analyzed by using phase Doppler anemometry. The result indicates that the downstream spray field mainly includes central toroidal recirculation zone，high-speed zone and spray edge zone，but there exists a step low-speed zone in the high-speed zone at X=10mm section. The spray structure gradually changes from a hollow-conical structure to full cone-type. Along axial the linear averaged Sauter mean diameter ^-SMD ^--^- increases，and the airflow pressure drop has a major impact on mean droplet size. The atomization processes in the atomizer accord with hybrid airblast atomization. At the near field region of X=10mm section，the droplet axial velocity is basically independent with the droplet size in radially，while the correlation between droplet radial velocity and droplet size is related to the radially position. Revising the previously proposed empirical prediction formula，a droplet size correlation applicable to this atomizer is obtained. In addition，the first and second swirling airflow are the dominant factor of mean droplet size in the near field region when the pressure drop of airflow is 4kPa，the third swirling airflow could be ignored.