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Turbine Blades Terry Andersen Nathan Stastny ME 372 Brigham Young University Fall 2001

Turbine Blades

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Turbine Blades

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  • Turbine Blades

    Terry AndersenNathan Stastny

    ME 372Brigham Young UniversityFall 2001

  • OverviewApplicationsDesign ConsiderationsMaterial ConsiderationsManufacturing ProcessesReviewQuestions

  • ApplicationsGas Turbine GeneratorsJet Engines

  • Rolls RoyceRolls Royce Trent Turbine Blades

  • Design ConsiderationsGeometryCooling VanesAttachment InterfaceSafety Factors

  • GeometryStrength / Fatigue LifeEach row will be differentAir Flow (CFD Package)MachineabilityGeneral Turbine Blade Shape

  • Cooling VanesBlades must be kept coolOften operate near the metal melting pointAn increase of only 17 C can decrease the engine life by halfCool (300 C ) air is run out of the blades through small holes (vanes), keeping the blades from melting.

  • Pic

  • AttachmentKeep Stress Concentrations LowFir Tree AttachmentReduced stress concentrationsEasy replacementAlso known as the Christmas Tree

  • Safety FactorsHigher S.F. is usually the best.But what if the engine runs out of control at speeds higher than intended?The energy of the rotating blades goes up with 2What happens if the blades brake at 10% overload? 20%, 30%, 40%, 50% ?Too much energy and the blades might break through the engine shroud and into the fuselage.

  • Quick Video

    Boeing 777Engine Test

  • Material ConsiderationsEnvironmentCreepCurrent Materials UsedMaterials In Research

  • EnvironmentAir Temperature: Between 850 and 1600C Melting Temperature:Steel:1400C Nickel Alloy: 1200C Titanium:1650C Turbine RPM: Appx. 20,000 rpm

  • CreepTurbine blades elongate during their lifeTip clearanceResult of environment and grain structureSoft abradable liningDirectional solidification (cooling)Single crystal structure

  • Current Materials UsedInitially SteelNickel AlloysMost common material is TitaniumLaser peeningCeramic Coatings

  • Material In ResearchCeramic blades

    Carbon composite bladesNoise reductionLight weight

  • Manufacturing ProcessesMachining (not too common)Investment CastingSecondary machiningElectro-Chemical MachiningSingle operation

  • Design Siteswww.pccsmp.com (manufacturing)www.turboblades.com (manufacturing)www.giverin.demon.co.uk/NewFiles/HTWTurbines.html (information)www.gas-turbines.com/begin (information)www.pratt-whitney.com (engine manufacturer)

  • ReviewApplications: Jet EnginesGas Turbine GeneratorsDesign Factors: Geometry S.F.Materials:Very high temperaturesTitaniumManufacturing:

  • Questions

  • TerryNathanDr. ChaseSquadron CommanderSpecial thanks to all those who didnt believe in us, but whom weve proved wrong.