Investigation on the effect of injector modification on injector atomization and u-bend pulse detonation combustion characteristics

In order to shorten the deflagration-to-detonation transition (DDT) distance of the pulse detonation combustion chamber, an experimental study of the effect of pneumatic atomization injector modification on atomization particle size amd gas-liquid two-phase U-bend pulse detonation combustion (U-PDC) chamber was carried out. Gasoline and air were used as fuel and oxidizer, and the atomization particle size was tested and the detonation characteristics of the U-PDC were obtained using the pneumatic atomization injector before and after the modification. The results show that the atomization size range of the injector before the modification is 111.6 similar to 152.9 mu m, after the modification of the injector atomization size range of 76.4 similar to 107.2 mu m, atomization size than before the modification is significantly reduced. The U-PDC using the injector before and after the modification can achieve stable operation in the range of 10 similar to 30 Hz, and the DDT distance shortened with the increase in frequency. At an operating frequency of 30 Hz, the DDT distance of U-PDC with the injector before modification is about 676 mm, and the DDT distance of U-PDC with injector after modification is shortened by 8.9% to about 616 mm. In addition, under the same operating conditions, due to the better atomization effect of the injector after modification, The fuel flow rate of U-PDC with the injector after modification is 5 similar to 10% smaller than that with the injector before modification when the average detonation pressure reaches its maximum value during the adjustment of fuel-flow.