I found this from junk. Can you tell me what this is?
Turbocharger? One impeller compresses air, the other impeller expands it.
Yes, it is part of a turbocharger. Called the "core" it sits inside a housing that ducts the air.
thanks for your help. I am willing to use impeller and compressor in a jet engine out of it. Is it possible to use this existing design?
I mean a small one.
Possibly yes, turbochargers are used to make amateur turbojets. There are many out there. Search the web for sites.
The problems you will have is the quality of the shaft bushing and the provision of forced lubrication. The shape of the outer case of the rotor balances the forces on the centre bearing. You will have to design for that axial pressure.
The material used for the turbines is often different for a diesel or a gasoline engine. You will need to keep your exhaust temperature cool enough, and with the right oxygen level to prevent corrosion or melting of the turbine.
There are plenty of jet engine designs on the web that use a turbocharger as the compressor. But if you don't have the outer casing of the turbo as well as the rotor you showed in the pictures, that rather defeats the reason for using it, which is that building a small efficient compressor needs a "Swiss watchmaking" level engineering tolerances to be successful, otherwise air leakages between the rotor and casing will make it liable to stall and/or surge, or mechanically self-destruct if the rotor touches the casing at high RPM.
Making a turbine that is "good enough" for a working engine is much less critical. Unlike compressors, the performance of a badly designed or inefficient turbine usually degrades in a "stable" manner, rather than catastrophically.
Here's a cut-away "real world" engine from the 1950s with twin radial compressors. Note, most of the structure "in front of" the compressors (at the left of the picture) is the reduction gearbox to drive the aircraft propeller, not part of the engine itself.
That's a very good picture! Thanks for sharing!
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