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Ramjets and Scramjets


Ramjet basics
Selected engines


A ramjet uses the ram effect, compression in an inlet, for all of the compression in an engine. Hence, it has no rotor or blades; the air is compressed by the inlet (using a series of internal/external shocks), ignited, and shot out the back by the nozzle. Because of the flow energy need to accomplish this, ramjets must be operated at high speeds. They are incapable of drawing in air at a standstill.

A normal ramjet uses oblique shocks to slow the flow with low pressure loss, and a final normal shock to drive the flow subsonic. For much higher speeds, it is proposed to keep the flow supersonic throughout the engine. This is called a supersonic combustion ramjet, or scramjet. Such an engine was envisioned for the X-30 National Aerospace Plane, as well as for future aerospace planes. Russia has tested a scramjet by strapping it to a rocket to get it up to speed; data on these tests are spotty at best.


We have little data for you at the moment. Enjoy these pretty pictures of the Talos, a formerly used naval surface to surface / surface to air missile reactivated to serve as a target drone simulating an anti-ship missile.

The Talos is launched by a first stage solid rocket motor which pushes it up to ramjet speed. When the missile reaches speed the first stage is discarded and the ramjet takes over.

The ramjet starts with the internal/external compression inlet and ends at the black bands by the middle set of fins.


A Talos is launched.


The ramjet portion of the Talos.