Control of a dlphasic assited atomization flow with physical and droplet size measurements

Abstract

A high-e ective combustion in the thrust chamber of a rocket engine is strongly dependant of the spray quality. Thus, in order to maximize the e ciency is important to understand and control the phenomena responsible for the atomization. In the case of assisted atomization, studied in this project and widely used in combustion chambers of jet and rocket engines , the break-up of a liquid jet by a parallel fast gas stream occurs due to the successive instabilities appearing on the interface of the two uids, triggered by the velocity di erences between them. In the present project, a study of the apping instability has been carried out, this instability is a large-scale phenomenon in which the liquid jet su ers a marked oscillation far downstream the injector. Large liquid injection diameters have been investigated concerning this instability, noting that, in this case, the shear instability does not bring about the apparition of the apping for variable gas velocities. A possible potential dependency on the liquid jet velocities has been examined. In addition, a study of the in uence of the apping instability in the spray droplet size has been performed, nding a clear impact of the instability on them. v