Time rotor

The Time Rotor is the component in the central column of the TARDIS console. When the Tardis is traveling the rotor rises up and down until it has reached a destination. It is associated with the 'whooshing' noise heard when the TARDIS is in flight. The aesthetic design, along with the rest of the TARDIS, has changed throughout the history of the Doctor Who franchise.

It is interesting to note that in the non-canon Dalek movie spin-offs, Doctor Who and the Daleks and Daleks - Invasion Earth 2150 AD, the Tardis lacked the time rotor or even a central console.