Cool though their turbofan isn't going to work very well with the compressor being much larger than the turbine - the gas would find it easier to flow the wrong way. The Wikipedia animation has more promising dimensions https://en.wikipedia.org/wiki/Turbofan
After remarking on how boring jet engines are, the page gets vague and states that the turbofan increases "fuel efficiency", without explaining why or how. I've seen it assumed elsewhere that the efficiency of turbofans is due to thermodynamic effects. In this case, what the author wrote is vague about the mechanics of it, at best.
This has baffled me since I was two years old. The burning fuel should push in all directions equally. What makes it go more out the back than the front?
It's easier if you imagine identical fans for the compressor and turbine but gearing so the turbine can spin faster. Of course the gasses will take the easy way out the turbine. At some speed, air stops going out the compressor and comes in instead. Burning fuel keeps the gas expanding so there's still a lot more volume to go through the turbine. Then adjust blade angles and turbine diameters to get rid of the gearing.
Or another way. If the thing was symmetrical the pressure would push both ways and it wouldn't move so the designers have to make it asymmetrical so it's easier to get out the exhaust. I think in practice the compressor blades are closer to perpendicular to the flow than the exhaust turbine ones.
It's also important that there is a larger volume of gas leaving the engine than going in as it expands when the fuel heats it. So while the pressure is the same the energy is greater on the turbine side due to the greater volume so it has power to run the compressor as well as fly the plane.
That's what all the compressor stages are for. There's a pressure differential so the combustion pushes against that and exits in one direction, turning the lower pressure discs on its way out.
