Sökning: "mistuning"

Hittade 5 avhandlingar innehållade ordet mistuning.

1. 1. Numerical investigation of the sensitivity of forced response characteristics of bladed disks to mistuning

   Författare :Mikkel Myhre; KTH; []
   Nyckelord :aircraft engines; gas turbines; bladed disk assemblies; vibrations; high cycle fatigue; forced response; mistuning;

   Sammanfattning : Two state of the art finite element reduction techniquespreviously validated against the direct finite element method,one based on classical modal analysis and another based oncomponent mode synthesis, are applied for efficient mistunedfree vibration and forced response analysis of several bladeddisk geometries. The methods are first applied to two testcases in order to demonstrate the differences in computationalefficiency as well as to validate the methods againstexperimental data. LÄS MER

3. 2. Development of Accurate Reduced Order Models in a Simulation Tool for Turbomachinery Aeromechanical Phenomena

   Författare :Mauricio Gutierrez Salas; Björn Laumert; Paul Petrie-Repar; Damian Vogt; Carlos Martel; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; flutter; forced response; high cycle fatigue; reduced order models; ROM; craig-bampton; mistuning; tuned; mistuned; cyclic; noncyclic; craig-chang; free-interface. fixed-interface; subset nominal mode; SNM; CBMS; CCMS; CCC; CBC; FEM; CMS; modal; eigen; modeshapes; aeroelasticity; aeromechanical; tool; turbomachinery; turbine; compressor; AROMA; Energy Technology; Energiteknik;

   Sammanfattning : Modern gas turbines are still vulnerable to vibrations when operated at certain speeds. This unstable environment can lead to high cycle fatigue (HCF) and damage several of the components inside the turbine. LÄS MER

4. 3. Development and Validation of a Numerical Tool for the Aeromechanical Design of Turbomachinery

   Författare :María Angélica Mayorca; Torsten Fransson; Damian Vogt; Eric Seinturier; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; aeromechanical design; turbomachinery; numerical tool; reduced order modeling; mistuning; ROM; aero-structure coupling; CFD; FEM; methods; Mechanical energy engineering; Mekanisk energiteknik;

   Sammanfattning : In aeromechanical design one of the major rules is to operate under High Cyclic Fatigue (HCF) margins and away from flutter. The level of dynamic excitations and risk of HCF can be estimated by performing forced response analyses from blade row interaction forces or Low Engine Order (LEO) excitation mechanisms. LÄS MER

5. 4. Numerical Methods for Turbomachinery Aeromechanical Predictions

   Författare :Maria Angelica Mayorca; Damian Vogt; Torsten Fransson; Robert Kielb; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Aeromechanics; numerical tools; methods; turbomachinery; aeroelasticity; gas turbines; vibrations;

   Sammanfattning : In both aviation and power generation, gas turbines are used as key components. An important driver of technological advance in gas turbines is the race towards environmentally friendly machines, decreasing the fuel burn, community noise and NOx emissions. LÄS MER

7. 5. Sensitivity of Aeroelastic Properties of an Oscillating LPT Cascade

   Författare :Nenad Glodic; Damian Vogt; Matthew Montgomery; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; flutter; aeroelastic response; combined modes; bending-torsion flutter; mode superposition; aerodynamic asymmetries; ROM; probabilistic analysis;

   Sammanfattning : Modern turbomachinery design is characterized by a tendency towards thinner, lighter and highly loaded blades, which in turn gives rise to increased sensitivity to flow induced vibration such as flutter. Flutter is a self-excited and self-sustained instability phenomenon that may lead to structural failure due to High Cycle Fatigue (HCF) or material overload. LÄS MER