What type of engine requires a high-speed airflow in order to operate effectively?

The ramjet and scramjet are types of air-breathing engines that operate on the principle of utilizing high-speed airflow to compress incoming air before combustion. For a ramjet, the engine lacks moving parts and relies on the forward speed of the aircraft to compress the air. As the aircraft moves at supersonic speeds, the air enters the engine, gets compressed by the shape of the inlet, mixes with fuel, and is ignited. The expansion of the heated gases generates thrust.

In a scramjet, which operates at hypersonic speeds, the airflow remains supersonic throughout the engine. Similar to the ramjet, it also uses high-speed airflow for compression and combustion, but it is designed to handle much higher speeds, making it even more dependent on that fast incoming air stream.

This contrasts significantly with the turbofan, turboprop, and reciprocating engines, which generate thrust by mechanically compressing air using fans or turbines rather than relying solely on the speed of the aircraft. These engines usually function effectively across a range of speeds but do not require the high-speed airflow necessary for ramjets or scramjets to operate. Thus, understanding the unique operating principles of each engine type shows why the ramjet and scr