Here's the next video in our quest to understand jet engine and rocket nozzles (among other things). We will be talking about the sonic state, which is also called the critical state or the star state.

These values are useful for determining whether flow through a nozzle is choked. If the nozzle is indeed choked, then the sonic state values (P*, rho*, T*, etc.) are the actual static quantities at the throat of the nozzle.

===== RELEVANT VIDEOS =====
→ Stagnation Relations
https://goo.gl/FMFUBA

→ AreaMach Number Relation
https://goo.gl/Hp6uGQ

===== REFERENCES =====

► Notes by Matt MacLean
► Modern Compressible Flow, Anderson
► Elements of Gasdynamics, Liepmann and Roshko
► Gas Dynamics, Zucrow and Hoffman

===== THUMBNAIL =====
By Ad Meskens (Own work) [Attribution, GFDL (http://www.gnu.org/copyleft/fdl.html) or CC BYSA 4.03.02.52.01.0 (http://creativecommons.org/licenses/b...)], via Wikimedia Commons