TARDIS to those first seen in 1963, with multiple roundels illuminated from behind. The fourth major redesign of the TARDIS in the revived series appeared in the eleventh series. New production designer Arwel Wyn Jones said that the inspiration for the Thirteenth Doctor's TARDIS was based on the 2005-10 model, which he had worked on. The console room is the "safest place on the ship," and so when its occupants are in danger the TARDIS will reinvent its architecture so as to allow them to enter the console room. This can also result in the TARDIS materialising itself within its own
Working fluid Working fluid A working fluid is a pressurized gas or liquid that actuates a machine or heat engine. Examples include steam in a steam engine, air in a hot air engine and hydraulic fluid in a hydraulic motor or hydraulic cylinder. More generally, in a thermodynamic system, the working fluid is a liquid or gas that absorbs or transmits energy. The working fluid properties are essential for the full description of thermodynamic systems. Although working fluids have a very large number of physical properties which can be defined, the thermodynamic properties which are often required in engineering design and analysis