Fluids travel in two ways, either gently like honey out of a pot, these flows are 'laminar', or erratically changing direction in seemingly incoherent and unpredictable way, like a mountain stream, these are 'turbulent'.
What is fascinating is that even in simple flows such as those inside the plumbing pipes of our houses, fluids can spontaneously switch between these two behaviours. They can even behave in both ways at the same time!
Yet laminar and turbulent flows are everywhere. When in one or the other state, the drag on planes, boats, cars, how much power is needed to pump fluid through a pipe etc can be very small for laminar flows or enormous for turbulent flow. So what makes flows turbulent or laminar?
Can we control flows into one or the other states to suit our needs? To glimpse into these questions, you will run a fluid flow down our 12m long transparent pipe where ultra-fast cameras and LASERS will reveal the detail of how the flows choose to be either turbulent or laminar...