To spill or not: Short-time pouring dynamics of a toppled liquid bottle

A typical culinary setting involves liquid condiments with different constitutive behaviors stored in jars, bottles, pitchers, or spouts. In the dynamic kitchen environment, handling these condiments might require pouring, drizzling, squeezing, or tapping, demonstrating the interplay of the container geometry, the fluid properties, and the culinary expertise. There is, of course, the occasional accidental toppling. We investigate the combined effects of surface properties, fluid properties, and confinement dimensions on the short-time spilling or pouring dynamics of a toppled cuvette. While attesting to the fact that smaller cuvettes (which can be termed as capillaries as well) do not spontaneously spill, larger cuvettes exhibit spilling dynamics that are dependent on the surface property, fluid viscosity, and flow rheology. For Newtonian liquids, it is observed that the spilling dynamics are determined largely by the coupling of viscous and gravity forces with surface properties, inducing non-intuitive behavior at higher conduit dimensions. The inclusion of rheology for non-Newtonian liquids in the soup makes the spilling dynamics not only an interplay surface and fluid properties but also a function of meniscus retraction demarcating a “splatter” of three regimes “not spilling,” “on the verge of spilling,” and “spontaneous spilling.” We not only delineate the interactions leading to meniscus motion but also provide a mapping on whether or not a container would spill if it is momentarily toppled and then immediately returned to upright position. This study aids in understanding the fascinating physics of fluid pouring dynamics and could lead to new kitchen, biomedical, and industrial technologies.