Editing Turbofan (section)

=== Aerodynamic modelling ===
[[Aerodynamics]] is a mix of [[Speed of sound|subsonic]], [[transonic]] and [[supersonic]] airflow on a single fan/[[gas compressor]] blade in a modern turbofan. The airflow past the blades must be maintained within close angular limits to keep the air flowing against an increasing pressure. Otherwise air will be rejected back out of the intake.<ref name=LN161021>{{cite web |url= https://leehamnews.com/2016/10/21/bjorns-corner-engine-challenge/ |title= Bjorn's Corner: The Engine challenge |author= Bjorn Fehrm |date= October 21, 2016 |work= Leeham News}}</ref>

The [[FADEC|Full Authority Digital Engine Control]] (FADEC) needs accurate data for controlling the engine. The critical [[turbine]] inlet temperature (TIT) is too harsh an environment, at {{cvt|1700|°C|°F|sigfig=2}} and {{cvt|17|bar|psi}}, for reliable [[temperature sensor|sensor]]s. Therefore, during development of a new engine type a relation is established between a more easily measured temperature like [[exhaust gas]] temperature and the TIT. Monitoring the exhaust gas temperature is then used to make sure the engine does not run too hot.<ref name=LN161021/>