thinking womanIf you recall, we were shocked by the idea that a jet could be created that could go Mach 24 in the blog “Will a Mach 24 jet leave supersonic planes in their dust?” But that was only a theoretical design that had the potential to work. A new engine called the HIFiRE 5b has not only been designed, but has been created and tested. It doesn’t go Mach 24, but it still leaves supersonic planes in the Fifty Shades Darker 2017 movie

How is the HIFiRE 5b able to reach such speeds?

First you must understand how a plane is pushed forward and how that movement has evolved to get us where we are today.

  • propellerFirst was a propeller. These looked like fan blades moving very fast on the front of the wing. They moved air past the plane to move it forward.
  • Next was the turbine engine, what is being used by jets today. Several fans inside a tube pull air into a compressed area, fuel is put into the compressed air and lit on fire. When the compressed air and the ignition of the fuel come together, it pushes the jet faster than a propeller ever could, but only so fast. At some point, the speed can become so fast that the parts of a turbine fly apart.
  • Now we have what is called a “ramjet” and just as the name implies, air outside the engine must be rammed into the engine at high speeds. In this engine, the fans were taken out and instead the engine simply allowed the air already passing by the ramjetplane to be pushed into a compressed area with a different type of fuel. This fuel was not simply put into the compressed air, the fuel was compressed and heated first. Then put into the compressed air and ignited causing even more speed. This engine needs a small assist to get it up to a speed where the air can be compressed around it to light the engine, but once lit, it can go Mach 5 easily, but at Mach 5 the shock wave became a barrier pushing back against it, keeping it from going any faster.
  • The new engine is called a “scramjet” simply because it is built off of the idea of the ramjet. The compressed air, from traveling even faster, combines with even more compressed and heated fuel but like the ramjet, if the parts are not smooth, with fewer edges, then they will limit how fast the engine can move the jet. Also, like the ramjet, the scramjet requires an assist to get started, but it needs a big one. The scramjet has to be moving at Mach 3 before it will ignite because nothing within the engine moves, at all. That means the air has to be moving into it at Mach 3 for it to become compressed enough to work, but once it is and the highly pressed and heated fuel ignites, it can easily go almost Mach 8!

Where are we going with scramjets?

speed light effectsJets with scramjet engines have already been built, test flown, and even have a few variations of jet that they can work with. The final hurdle that designers are conquering before they turn these engines toward commercial planes is the Mach 3 assist speed. Their solution is a convertible engine! They have created an engine that begins as a turbine engine, folds down its fans to become supersonic, and then flattens out its edges to become hypersonic. The engine has been created, the only question is, how soon will we have the opportunity to buy a plane ticket to get us from New York to Los Angeles in 45 minutes? I wouldn’t ask how much it costs though, no matter how fuel efficient it is.