turboramjet

A turboramjet is a type of jet engine designed to operate efficiently across a wider range of flight speeds than a standard ramjet. A ramjet is efficient at high supersonic speeds but struggles at lower speeds.1

The turboramjet addresses this by incorporating a turbofan engine within the ramjet's inlet. This turbofan provides a pressurized air supply at subsonic speeds, where ram pressure is insufficient for effective ramjet operation. During supersonic flight, the turbofan's blades can be adjusted to minimize interference with airflow, and its air intake can be sealed to protect the machinery from hot ram air.1

Alternatively, some turboramjets omit the core compressor and carry an oxidizer, like liquid oxygen, to fuel the turbine that drives the fan. This allows for additional fuel to be burned in the exhaust, increasing jet temperatures beyond what turbine blades can withstand.2