# @stem_antics on Instagram

- **Type:** Video
- **Original URL:** https://www.instagram.com/p/DUdg6WaEXzk
- **Gondola URL:** https://gondola.cc/posts/61936065-stem-antics-instagram
- **Thumbnail:** https://img.gondola.cc/tr:w-,h-,fo-auto/postThumbnails/9d8c64e730.jpg
- **Posted:** 2026-02-07T15:08:42.000+00:00
- **Account Owner:** Stem Antics (@stem_antics) — https://gondola.cc/stem_antics

## Caption

Jet engines all do the same job—turn fuel into thrust—but how they do it depends heavily on speed. Turbojets, ramjets, and scramjets each occupy a different slice of the velocity spectrum, and the physics inside them changes dramatically as airflow transitions from subsonic to hypersonic.

A turbojet uses rotating machinery to do the hard work. Incoming air is compressed mechanically by axial or centrifugal compressors, mixed with fuel, ignited, and expanded through a turbine and exhaust nozzle. The turbine steals some energy to keep the compressor spinning, and the remaining momentum produces thrust. Turbojets are efficient at low to high subsonic speeds and were common in early jet aircraft, but their moving parts limit efficiency and survivability at extreme Mach numbers.

A ramjet removes the compressor and turbine entirely. Instead, it relies on the aircraft’s forward speed to compress incoming air through shock waves in the inlet. Fuel is injected into this compressed air and burned, then expanded out the nozzle. Fewer parts means lighter weight and higher temperature tolerance—but ramjets cannot operate from rest. They only work once the vehicle is already moving fast, typically above Mach 2.

A scramjet (supersonic combustion ramjet) pushes this concept even further. In a scramjet, airflow remains supersonic throughout the engine, including during combustion. This avoids massive pressure losses caused by slowing air to subsonic speeds at hypersonic velocities. The tradeoff is extreme complexity: fuel must ignite and burn in milliseconds while moving faster than a rifle bullet. Scramjets are experimental, but they represent one of the few viable paths to sustained hypersonic flight.

Same goal. Very different physics. Speed changes everything.

#STEMeducation #AerospaceEngineering #JetEngines #Hypersonics #EngineeringExplained

## Stats

- **Views:** 7,563
- **Likes:** 218
- **Shares:** 0
- **Comments:** 2

## Tags

jetengines, stemeducation, hypersonics, engineeringexplained, aerospaceengineering

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