Ram effect on turbocharged engines?

Discussion in 'Engines' started by tomo pauk, Oct 9, 2011.

  1. tomo pauk

    tomo pauk Creator of Interesting Threads

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    Or, was it producing any substantial effects on engines powering planes at high speed ?
     
  2. Shortround6

    Shortround6 Well-Known Member

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    ram was always useful. Say for instance you are flying at 25,000ft where the air has a pressure of 11.10lbs/sq in (from old chart) if your forward speed can raise the pressure in the intake duct just before the supercharger or carburetor by just ONE lb/square in ch the plane will think it is flying at 23,000ft. If you can raise it by just over two lbs/sq in the plane will think it is flying at 21,000ft. It doesn't matter what kind of supercharger system is being used.
     
  3. vanir

    vanir Banned

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    That's it exactly. It's an altitude thing, not really a horsepower thing. Like series blowers, even overboost involves an altitude/output equation moreso than turning a docile creature into a monster.

    These things behave differently in an aero engine to an auto engine. On aero engines everything performance related is to do with altitude. Even take the power charts. On an auto engine power charts are by rpm. On an aero engine they're by altitude. This is the central crux of precisely how and why they're very different.
     
  4. tomo pauk

    tomo pauk Creator of Interesting Threads

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    Thanks, people :)
     
  5. herman1rg

    herman1rg Well-Known Member

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    Temperature of the air also has an effect. Air is densest at 4deg C and a combustion engine will burn most efficiently with air at that temperature. I formerly worked running RR jet engine based power stations and a 50MW station would be lucky to generate c42MW at 28deg C also the exhaust emissions would be dirtier. At 4deg C 50MW no problem and very clean emissions.
     
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