# [TECH] Jet Engine
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**The Jet Engine** (gas turbine) replaced piston engines for aircraft propulsion (1940s), enabling supersonic flight, mass air travel, and cargo transport.
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## Overview
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Frank Whittle (UK) and Hans von Ohain (Germany) independently developed jet engines (1939–1941). The turbojet compresses air, combusts fuel, and expands hot gases through a turbine to generate thrust. The turbofan (1960s) added a large fan for efficiency; high-bypass turbofans power all modern airliners. Gas turbines also generate ~25% of global electricity. The Rolls-Royce Merlin's success and the subsequent jet development programme created the modern aerospace industry.
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## Key Actors
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- **Companies**: Rolls-Royce (UK), Pratt & Whitney (US), GE Aviation (US), CFM International (US/FR joint)
- **Inventors**: Frank Whittle (1907–1996), Hans von Ohain (1911–1998)
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## Key Patents
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- Whittle, F. UK Patent 347,206 (1930) — jet propulsion (application)
- von Ohain, H. DE Patent 317/38 (1936) — jet propulsion
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## Economic Value
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Global aircraft engine market: **$95 billion/year** (2023, Roland Berger). Aviation enabled by jet engines: ~$900B/year airline revenue; global air transport enables $3.5T in trade and tourism.
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## Notes
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Roland Berger *Aerospace & Defense* 2023. IATA *World Air Transport Statistics* 2023.
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# Parents
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* [SCI] Aerodynamics⏎