Single & Two-Phase Supersonic Ejectors for Refrigeration Applications

At a first glance, the nature of this thesis may be considered somehow “sui generis”. By the author’s choice, its structure is not conceived as a report of the doctoral activities, but rather as a guide that can help the reader to appreciate the phenomena and critical points arising in the context of supersonic ejector research. The rationale for this choice has progressively appeared clear in the course of the doctoral period. During the last two decades, the literature on ejector refrigeration has become mostly self-referential. However, deep understanding of the physics governing both single- and two-phase high-speed phenomena requires a strong effort in terms of “broadening the research horizons”. Work of high relevance to supersonic ejectors can be found in the fields of aerospace propulsion, wind tunnel, steam turbines and turbomachinery cavitation research areas. Consequently, the character of this dissertation is shaped by the firm belief that major advancements may only come by joining together the knowledge from all these different disciplines. Under this perspective, the main results of this three-year doctoral research should not only be considered the achievements in ejector chiller performances or the developments of analytical and numerical tools, but also the opening-up to different research fields and the elaboration of a logical structure where all the themes are rationally presented.