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I'm toying with turbojet engine ideas, and over the course of my research it occurred to me that the combustion chamber could be more power-efficient and space-efficient if it was aligned in the desired direction of airflow.

That said, if the combustion chamber is 1-2 feet long, and both the intake and exhaust turbo manifolds need to connect directly to opposite ends of the combustion chamber, then the intake and exhaust portions of the turbo would need to be separated from each other and the shaft extended to allow room for the combustion chamber.

Basically something like the picture below, but with the combustion chamber rotated 90 degrees counter-clockwise-ish to eliminate the long intake tube.

If the shaft were extended, and the compressor further distanced from the turbine, how would this affect the central bits of the turbocharger, and the oil circulation?

(Source for the photo, and here's what it looks like when operating.)

colinfurze turbojet

Giffyguy
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1 Answers1

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A few things to consider if you end up doing this:

  • A longer shaft will reduce the speed that you can safely spin the turbos up to

    It's got to do with something engineers call rotordynamics, although I highly doubt you would need to spin something up to 125,000 RPM for a turbojet application :)

    You may also find that the existing journal bearings are not adequate for the requirements for the purposes of rotordynamic stability, so choose your turbo wisely

  • Consider modifying the oil supply system

    The shaft on an automotive turbo is relatively short, so both turbine-side and compressor-side bearings can be fed by a common oil supply. As you want to do away with the turbo housing, you will probably have to make it the oil supply system external to it.

    Turbo Cutaway

Zaid
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