Fluids Demonstrations II: Bubbles in Mondrian Painting, Eruption-Like Flow, Rotational Instability, and Wake Vortices

The purpose of this paper is to present five new devices that demonstrate a variety of flow phenomena in liquids and granular materials that exhibit fluid-like behavior. These devices complement and add on to a recent collection of demonstrations that was published in this journal. The devices are self-contained and portable, and can be utilized repeatedly without waiting or cleanup between uses. Furthermore, since the demonstrations result in visually engaging patterns, they are accessible to everyone regardless of age or science background. Descriptions are provided to enable replication by others. Significance of each demonstration is outlined and background information on the relevant physics can be found in the cited references. Pedagogical directions for specific use are left to the discretion of readers (depending on the scope of local interests and constraints). However, they can be used in classroom lecture demonstrations, outreach activities, or other student-based projects.