Fluid mechanics of tea poured from a teapot

• Main Author: Ahsan, Eatsham
• Other Authors: Chiew Yee Meng
• Format: Final Year Project
• Language: English
• Published: 2018
• Subjects: DRNTU::Engineering::Civil engineering::Water resources
• Online Access: http://hdl.handle.net/10356/75239
• Institution: Nanyang Technological University

When tea is poured from a teapot, we often find some tea travels down the underside of the spout and eventually detaches and drips. This phenomenon has been termed “the teapot effect”. This is often the cause of frustration and conventional wisdom provides us with certain solutions to reduce the chances of dripping, from special pouring methods to applying butter on the underside of the spout. However, we didn’t know much about the reasons behind the phenomenon and physicists often attributed it to surface tension and capillary action. Unsatisfied by this reasoning, some scientists, in the 1950s, started to look into the phenomenon and since then many have proposed various theories for the mechanism involved and have identified a myriad of factors that may cause the teapot effect. Some of these theories and factors were analysed and tested in this study. The phenomenon is also not exclusive to teapots and has been observed during pouring from a wine bottle and when rain flows down window frames. Lessons from these instances helped identify some additional factors and possible to solutions to prevent the teapot effect from occurring.