drip drop drip drop

It's been a busy week with +1/2 away but we've muddled through to the end: the children are intact, the house is intact, the car is intact. Win! +1/2 is back late this evening and the children are super excited.

Stop reading now if you're not interested in physics...

While doing the dishes I started thinking about fluid flow. Fluid Dynamics is full of non-dimensional numbers such as the Froude number; this describes different flow regimes in open-channel or free surface flow; if Fr < 1 the flow is slow, Fr > 1 is fast. To go from one to the other the fluid has to make a hydraulic jump which is characterized by a rise in the surface level of the fluid. This is what you see when you run water into a sink.