NUMERICAL STUDY ON FILM BREAKUP IN LIQUID-LIQUID PINTLE INJECTORS WITH DIFFERENT DOUBLE-ROW SLOT ARRANGEMENTS

The film breakup process in liquid-liquid pintle injectors with double-row slots, with aligned slots or staggered slots, has been numerically studied and compared. The effects of slot arrangements and momentum ratios on breakup morphology, surface wave, breakup length, and spray angles are discussed in detail. The results show that the spray generated by aligned slots is a multicavity structure, and the spray by staggered slots can be described as a gear-like hollow conical structure. The surface wave on the liquid in the aligned-slot pintle is larger in magnitude than that in the staggered-slot pile. The phenomenon of the phase difference of surface waves on the adjacent spray fans can be observed in their intersection region with aligned slots. Increasing the momentum ratio promotes the surface waves on the film with aligned slots but weakens the intensity of disturbing waves with the staggered slots. The aligned-slot pintle forms a larger spray angle than the staggered-slot pintle. As the momentum ratio increases, the spray angle expands and the breakup length shortens for both slot arrangements. The atomization performance of the aligned-slot pintle is generally better than that of the staggered-slot pintle under the present simulation conditions. Film leakage occurs with the aligned slot arrangement, and it is less efficient to control the leakage rate by adjusting the radial mass flow rate.