What is the Difference Between Ramjet and Scramjet?

The main difference between ramjets and scramjets lies in their combustion processes and the speed at which they operate. Both ramjets and scramjets are experimental jet engines designed for hypersonic speeds, and they rely on the immense pressure created by supersonic airflow to compress the incoming air before combustion. However, they differ in how they handle and compress the incoming air.

• Ramjet: In a ramjet engine, the air is slowed down to subsonic velocities before combustion using shock cones or an expansion chamber. The air is compressed at the combustion point, where it is mixed with fuel and ignited. Ramjets require a starting speed of around Mach 3 and can sustain effective propulsion up to speeds of around Mach 6.
• Scramjet: In a scramjet engine, the air does not need to be slowed down to subsonic velocities before combustion. Instead, the combustion chamber is designed to handle supersonic air velocities. Scramjets achieve combustion with the intake still happening at supersonic speeds, allowing for even higher speeds. They can operate at speeds of around Mach 6 and above.

In summary, the key difference between ramjets and scramjets is that scramjets can operate at higher speeds due to their ability to handle supersonic air velocities during the combustion process, while ramjets must slow the air down to subsonic velocities before combustion.

Comparative Table: Ramjet vs Scramjet

Here is a table comparing the differences between ramjets and scramjets:

Both ramjets and scramjets are types of air-breathing jet engines designed for hypersonic speeds. They have no moving parts and rely on the pressures created by supersonic airflow into the engine to ignite fuel. The main difference between them is the speed of the airflow in their combustion chambers, with ramjets having subsonic airflow and scramjets having supersonic airflow. This difference results in varying levels of efficiency, temperatures, and operational speeds for each engine type.