Inside a Jet Engine: Follow the Air

How does a jet engine work? Follow the air through a transparent turbofan: the huge fan, compressor, combustor, turbines and two concentric shafts. See why most airflow can bypass the fire, and how hollow turbine blades use cooling air to survive the hot gas. 00:00 Air that misses the fire 00:51 The giant front fan 01:19 The 10:1 airflow split 02:51 Pressure, stage by stage 04:27 Inside the annular burner 05:32 Gas becomes shaft power 06:02 A shaft inside a shaft 07:07 Hot gas, cooler metal 07:38 Inside a hollow blade 08:44 Layers of thermal protection 09:53 Two streams, two exits 10:55 Follow air and power 11:25 The elevator safety brake This is an original animated teaching model of a two-spool high-bypass turbofan, inspired by published GE9X specifications. Geometry is simplified, rotation is slowed, and airflow paths are illustrated. It is not an OEM CAD model or a CFD simulation. The 10:1 bypass ratio describes bypass/core mass flow. About 91% is the arithmetic result of 10/11 at that ratio; it is not a universal flight-condition value or a thrust percentage. The 1700°C gas temperature is a general modern-turbine example described by Rolls-Royce, not a measurement of this modeled engine or its metal temperature. Cooling passages, holes and coating thickness are enlarged for visibility. Primary sources: NASA, turbofan arrangement and mass-flow ratio: https://www.grc.nasa.gov/www/k-12/BGP/turb... GE Aerospace, GE9X specifications: https://www.geaerospace.com/commercial/air... NASA, axial compressors: https://www.grc.nasa.gov/www/k-12/airplane... NASA, compressor thermodynamics: https://www.grc.nasa.gov/www/k-12/airplane... GE Aerospace, eleven-stage high-pressure compressor: https://www.geaerospace.com/news/articles/... NASA, annular burners: https://www.grc.nasa.gov/www/k-12/airplane... NASA, thrust: https://www1.grc.nasa.gov/beginners-guide-... NASA, film cooling: https://technology.nasa.gov/patent/LEW-TOP... NASA, turbine cooling: https://www.nasa.gov/special-projects-labo... NASA, thermal barrier coatings: https://www.nasa.gov/special-projects-labo... Rolls-Royce, turbine temperatures and cooling passages: https://www.rolls-royce.com/media/our-stor... NASA, nozzles: https://www.grc.nasa.gov/www/k-12/airplane... See every part move. Glassbox Engineering. Original code animation and synthetic sound/music. Narration generated with Kokoro; additional concept and thumbnail artwork generated with ChatGPT Images. Third-party cue sounds credited under the Pixabay license in the production source.