Injector Internal Geometry and Sub-Atmospheric Back Pressure Influence on Low Weber Number Liquid Flow

Nicolas Leboucher (1) , Christophe Dumouchel (1) , Denis Lisiecki (1) , Yves Wanner (1)

1 CORIA - Complexe de recherche interprofessionnel en aérothermochimie

The experimental work presented in this paper investigates the influence of the injector internal geometry on the primary atomization process in sub-atmospheric back pressure condition. A series of four injectors is studied. High-rate shadowgraph films of the liquid flow issuing from the nozzle are performed (66 667 fr/s). In order to have exploitable images, the injection pressure is maintained low (less than 1 MPa). On each image, the interface length per unit liquid surface area, e 2 (0), is measured. The examination of this parameter and of the images reveals that under atmospheric pressure, the primary atomization process is rather independent of the injectors. However, as the ambient pressure decreases, the injectors show different behaviour and the atomization process becomes intermittent. This behaviour is attributed to the apparition of cavitation in the injector. The characteristics of this intermittency are evaluated. Among other results, we observed that atomization process produced by cavitating flows are more sensitive to the injector internal geometry, the intermittency is due to the production of vortex cavitation, and, contrary to what is usually reported in the literature, cavitation does not enhance atomization in the present case. These results, as well as others, are presented and discussed in this paper.

Domaines: Sciences de l'ingénieur [physics]

Nicolas Leboucher, Christophe Dumouchel, Denis Lisiecki, Yves Wanner. Injector Internal Geometry and Sub-Atmospheric Back Pressure Influence on Low Weber Number Liquid Flow. International Conference on Liquid Atomization and Spray Systems, Sep 2012, Heidelberg (Germany), Germany. ⟨hal-03989925⟩