02 November 2009

Stopping a teapot from dribbling?

It took a lot of research but a team of fluid dynamics experts at the University of Lyons in France have worked out why a teapot dribbles (a phenomenon known as the "hydro-capillary effect").

Better still they also have the solution! And the answer is to deploy a "superhydrophobic" material (such as butter) down the spout.

According to the Telegraph they worked out that that at low pouring speeds tea starts to stick to the inside of the spout, causing the flow to momentarily stop and then start again. However, by reducing the friction between the spout and the fluid, the dribble can be all but be eradicated.

They recommend using the thinnest material possible for the lip of the spout, preferably metal, and applying an "hydrophobic" or water repelling substance to the inside. This will mean the tea literally glides off the surface and into your cup.
The findings demonstrated in the paper "Beating the teapot effect" were published in arXiv, the online science journal.

So there you have it (yet again). Butter? So that’s why Tibetans have their tea with Yak butter?

18 comments:

CherryPie said...

And there was me thinking it was down to the design of the spout!!

Sean Jeating said...

Watch out, Jams! One day it will be discovered that teapots can dribble like Georgie Best, and that they do even have the Matthews-trick in their repertoire.

Claude said...

I don't know the people Sean is talking about. I was wondering if a touch of butter in the mouth would stop old people from dribbling? Important for me to find a way...:)))))))

Claude said...

Jams, I read the whole article. Butter will not work on skin. Just on teapot ceramic. Do people get paid to solve teapot dribblings?

jams o donnell said...

Me too Cherie but now we know!

Ah now there's some dribbling we all would like to see Sean.. but perhaps not from the teapot!

Oh come, come Claudia! I'm sure that's the last thing you need!... As for the scientists, I am sure this is just a light hearted sideline to other research

SnoopyTheGoon said...

Methinks a light spraying by WD-40 will do it. Anytime.

jams o donnell said...

Ach but what of the tea taste Snoopy.. you are clearly a coffee drinker!

Stephanie, Mama Dramatist said...

Again, ARE FOLKS GETTING FUNDING FOR THIS??!!

I really can't tell my husband about this one...

And I will NEVER put butter in my tea!' Hrmph!

Stephanie, Mama Dramatist said...

Sorry for the outburst. We're writing a grant right now... little stressed... forgive me...

jams o donnell said...

I'm sure it was just a minor spin off from other more pressing work Stephanie. Good luck with the grant application. What is your husband's area of research?

Stephanie, Mama Dramatist said...

blood clotting disorders

jams o donnell said...

Very important research Stephanie

Stephanie, Mama Dramatist said...

Thank you. We think so.

James Higham said...

A question of laminar flow.

Stephanie, Mama Dramatist said...

Yes, James, or turbulent depending on the flow geometry ie whether or not particulate matter (ie leaves) are present.

But, then again, you can get into the whole concept of the "terrain" of the teapot, so to speak, and the idea of friction and flow dynamics...

We do that with blood. NOT TEA! We just drink the blasted tea!

Sorry. Retreating back to the hospital now...

jams o donnell said...

I'll duck oput of this one. Physics was a subject I never got on with.. or biophysics.. The noradrenergic innervation of the mucosa of the rat colon and then we're talking!

Stephanie, Mama Dramatist said...

Hee! I know a few rat colons.

jams o donnell said...

That is how I spent a lot of my final uni year - looking at sections of rat colons down a microscope . Did my degree in Physiology and Biochemistry but that was in the early 80s so I've forgotten most of it now!