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Turbochargers - clearance between turbine wheel and housing. Is it important?

  1. Dec 6, 2011 #1
    I am trying to find authority that the gap between the turbine wheel and the housing is important to the performance the turbocharger will be able to add to a diesel engine.
  2. jcsd
  3. Dec 8, 2011 #2


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    My guess is that is a very important parameter. The turbine is pressurizing air and a gap betwen the turbine and the housing would provide a path for pressurized air to escape, reducing the efficiency of the turbine.
  4. Dec 12, 2011 #3


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    Yes, it's a very important parameter. Not just from a performance point of view, but to avoid interference under extreme operating conditions (when the housing axis moves away from the shaft axis, overspeed, high temperatures, low oil pressure etc).
  5. Dec 12, 2011 #4
    Yep. An experimental supercharger I was working on had too little clearance. Worked fine until about 30,000 RPM, then the blade tips all but welded themselves to the casing. After running FEA, we found that the rotors were growing about 0.015" (radius) at full speed, instead of the 0.007"-0.010" of our other models.
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