CFD Online Discussion Forums

CFD Online Discussion Forums (
-   Main CFD Forum (
-   -   dripping (

Alexander Tong December 30, 1998 12:34

Hi! My name is Alex. I'm studying architecture in London. At the moment, I'm doing a project on dripping. My project based on a repetitive movement and I chose to study dripping of water from the tap in my kitchen. I am making an apparatus consisting a frame and a tank. This apparatus will be thrown on the ground. The frame looks like the feet of a spider that it will set up a particular pose depending the way it lands. The frame will determine the height of the tank from the ground and its deviation from the normal. It will set the tank in vibration after the impact with the ground. I am stuck with the design the tank. The tank should drip and it should provide several ways of dripping. My first model was a cubic tank with holes on the bottom. It was a failure since it drips only in one way. Perhaps I am very confusing. My question is very simple. What does dripping depend on? Would a vibration of the whole system change the way it dripped? Would anyone kindly give me some advices? Thank you.

John C. Chien December 30, 1998 13:23

Re: dripping
I am not sure what you are trying to do. But for the water to flow out of the tank, it's better to have one hole on the bottom and another hole on the top. Otherwise, the vacuum created inside the tank will stop the water flow.Once that is established, the vertical level( height measured from the bottom hole to the water surface inside the tank in the vertical direction) H will determine the pressure at the hole location as rho * g * H. This pressure is just like the water pressure at the kitchen faucet which determine the flow rate when the faucet is open. If you have the hole at the bottom of the tank positioned at the edge of the bottom, then the water level measured from the hole to the water surface will be more sensitive to the ground slope and this will change the water flow rate. If the water surface moves because of the transient motion of the tank, it will also affect the height of the water surface just above the hole. By the way, is there a real world application of this "dripping" experiment ?

Robin Bornoff January 4, 1999 13:14

Re: dripping
I saw an intersting paper once where a chaotic attractor was plotted as dT vs. dT-1 (i.e. time between drips compared the previous time between drips). It showed some inherent structure in an otherwise stochastic system.

Suffice to say even an apparently 'simple' system such as a dripping tap is a function of a number of non-linear coupled equations.

Good luck but why are you studying such a flow?


All times are GMT -4. The time now is 22:46.