China tests a new engine that accelerates jet aircraft and missiles to speeds exceeding Mach 6. The thing that makes this engine remarkable is that it’s air-breathing. Air-breathing hypersonic engines enable the creation of lighter systems with longer flight times. The air-breathing hypersonic aircraft or missile can fly at high altitudes. Those systems fly higher than regular aircraft but lower than satellites. And the thing that makes hypersonic systems have that ability is that they fly so fast. The high-speed flight squeezes air into the air inlet.
And. That makes it possible. To create a system that flies at very high altitudes. A big problem. With hypersonic engines, there are their compressors. Will not work at hypersonic speeds. The centripetal force destroys the compressor. So, the system needs an engine. That doesn’t need moving parts. The answer to that problem is the ramjet engine. The ramjet engine doesn’t use moving parts. The engine itself is the tube, where the airflow creates the pressure that starts the combustion. Normally, ramjet-driven systems are launched by using rockets. Or they are dropped from aircraft. And the rocket accelerates them to a speed that allows the ramjet or scramjet engine to start.
The scramjet engine is the engine that starts at Mach 6-8. And that hypersonic amjet is made for the speed. Those are beyond the ramjet operational top speed. There is a possibility that scramjet-driven systems. Like Boeing X-51 Waverider. It can be shot to a ballistic trajectory. Then the system dives back. Into the atmosphere, and the scramjet breathes air. This allows. For making Mach 12-capable hypersonic cruise missiles. The hypersonic aircraft can also send satellites. To an Earth orbiter. They can make the ballistic jump out of the atmosphere. And then they can launch satellite carriers. Those systems can also act as space fighters.
Boeing X-51 Waverider under B-52 Stratofortress.
“Schematic diagram showing the operation of a centrifugal flow turbojet engine. The compressor is driven by the turbine stage and throws the air outwards, requiring it to be redirected parallel to the axis of thrust.” (Wikipedia, Turbojet)
“Diagram of a valved pulsejet. 1 - Air enters through the valve and is mixed with fuel. 2 - The mixture is ignited, expands, closes the valve, and exits through the tailpipe, creating thrust. 3 - Low pressure in the engine opens the valve and draws in air.” (Wikipedia, Pulsejet)
“Simple ramjet operation, with Mach numbers of flow shown” (Wikipedia, Ramjet)
“Diagram of principle of operation of a scramjet engine.” (Wikipedia, Scramjet)
Ramjets have been used for a long time in air-defense missiles. The problem is that the ramjet cannot be started. Before the aircraft flies at a speed of Mach 1. The answer to the problem . It can be the system that uses the regular turbojets for lift-off and acceleration. When an aircraft reaches Mach 1, the fuel injection to the ramjet starts. And then the aircraft can fly at a speed. That is about Mach 6. Another version could be the pulsejet. The pulsejet or flap engine was developed for Germany’s V-1 “Flying bomb” during WW2. The system closes the flap in the front of the engine. Then the fuel. It will be injected into the combustion chamber. And then the system injects the fuel. When the pulsejet needs air, it opens the front valve.
And then the fuel injection starts in the combustion chamber. And then that system ignites the fuel-air mixture. The pulse-ramjet is a pulsejet that is formulated. As a ramjet engine. The system can use a compressor. That is the side of the engine. The compressor. It puts air. In the ramjet. The compressor system can transfer air to the ramjet. Before it reaches a speed of Mach 1. Then the system opens the front hatch. And let the air come into the combustion chamber. In rocket pulse-ramjets, the system can accelerate the aircrat to a speed of Mach 6.
That is the limit for the ramject engine. Then the system closes the front hatch and uses internal oxygen. That turns the pulse ramjet into a rocket engine. That allows the system to fly outside the atmosphere. Or it can accelerate. It into. Speed about Mach 8. That is the limit for the scramjet engine start. The scramjet engine makes it possible. To create aircraft and missiles that can travel over Mach 8. The high-speed flight must be done. In extremely high altitudes. Friction in the air is extreme. So the aircraft must fly almost in space.
https://www.afmc.af.mil/News/Article-Display/Article/153475/x-51a-waverider-achieves-history-in-final-flight/
https://www.eurasiantimes.com/invisible-to-radars-is-us-air-force-set/
https://interestingengineering.com/military/china-engine-mach-6-speeds
https://en.wikipedia.org/wiki/Boeing_X-51_Waverider
https://en.wikipedia.org/wiki/Lockheed_Martin_SR-72
https://en.wikipedia.org/wiki/Pulsejet
https://en.wikipedia.org/wiki/Ramjet
https://en.wikipedia.org/wiki/Scramjet
https://en.wikipedia.org/wiki/Turbojet
