"Jets are stupidly simple" Haha :D I don't know where that comes from. Jet engines are fiendishly complicated.
If they are so simple can you explain to me how interlaced rows of stator and rotor blades turn pressure into gas speed? That one always stumped me. Or how do I make monocrystalline blades, and how can I QA them? Or what exactly a FADEC do during startup, and how do the controlled parameters change depending on atmospheric conditions? Also I heard that the injectors and the air flow in the combustion chambers is designed such that there is an outside layer of incomplete combustion creating a colder laminar gasflow to protect the chamber wall itself. How do I go about designing that? How do I cool the bearings? How does one get the rotational energy out from the centre shaft to drive an oil pump on the side of the engine?
I mean these are just the first questions which pop up in my mind when I think about jet engines. And I'm not even a jet mechanic. If you truly think that jet engines are simple, then I envy your intellect.
I was referring to the operational complexity of the final product, not in the design or manufacturing. They have two main moving parts - the jet turbine, and the turbine connected to the fan (or prop). This is in comparison to the hundreds of moving parts your average ICE has for the drive train alone, not including the electrical system that lives alongside it to facilitate timed fuel ignition.
Jet engines are used on some older oil pumps because they can run for decades with minimal maintenance.
The initial comparison was turboprops vs. turbojets, so switching the comparison to the undoubted complexities of internal combustion piston engines is beside the point.
The 'jet' engines used on oil pumps etc. are actually not jet engines: they are gas turbines in which an additional turbine or turbine stage is used to extract rotational power - in other words, they are more like turboprop engines than jet engines.
Nevertheless, I do disagree with the suggestion that turboprops are much less safe than turbojets, and I suspect that the author of that comment was confusing them with piston engines, which also (almost always) use propellers (increasingly, we are seeing turboprop singles replacing piston twins.) Finally, piston engines themselves have become much more reliable since the days when they were the only option.
If they are so simple can you explain to me how interlaced rows of stator and rotor blades turn pressure into gas speed? That one always stumped me. Or how do I make monocrystalline blades, and how can I QA them? Or what exactly a FADEC do during startup, and how do the controlled parameters change depending on atmospheric conditions? Also I heard that the injectors and the air flow in the combustion chambers is designed such that there is an outside layer of incomplete combustion creating a colder laminar gasflow to protect the chamber wall itself. How do I go about designing that? How do I cool the bearings? How does one get the rotational energy out from the centre shaft to drive an oil pump on the side of the engine?
I mean these are just the first questions which pop up in my mind when I think about jet engines. And I'm not even a jet mechanic. If you truly think that jet engines are simple, then I envy your intellect.