Flow analysis from PIV in engraved champagne tasting glasses: flute versus coupe

Abstract

Glass shape, and especially its open aperture, is suspected to play an important role as concerns the kinetics of CO₂ and flavor release during champagne tasting. In recent years, much interest has been devoted to depict each and every parameter involved in the release of gaseous CO₂ from glasses poured with champagne. One cannot understand the bubbling and aromatic exhalation events in champagne tasting, however, without studying the flow-mixing mechanisms inside the glass. Indeed, a key assumption is that a causal link may exist between flow structures created in the wine due to bubble motion and the process of CO₂ release and flavor exhalation. In the present work, two quite emblematic types of champagne drinking vessels are studied. The particle image velocimetry technique has been used in order to reveal the velocity field of the liquid due to the ascending bubble-driven flow for both glasses poured with champagne. The contribution of glass shape on the flow patterns and CO₂ release in both glasses are discussed by the use of experimental results. The results show that the continuous flow of ascending bubbles strongly modifies the mixing and convection conditions of the surrounding liquid medium whose behavior is strongly glass shape dependent.