Search for dissertations about: "flutter turbine blade"

Showing result 1 - 5 of 9 swedish dissertations containing the words flutter turbine blade.

  1. 1. Flutter in sectored turbine vanes

    University dissertation from Stockholm : Energiteknik

    Author : Olga V. Chernysheva; KTH.; [2004]
    Keywords : turbomachinery; aerodynamics; unsteady CFD; design; flutter;

    Abstract : In order to eliminate or reduce vibration problems inturbomachines without a high increase in the complexity of thevibratory behavior, the adjacent airfoils around the wheel areoften mechanically connected together with lacing wires, tip orpart-span shrouds in a number of identical sectors. Although anaerodynamic stabilizing effect of tying airfoils together ingroups on the whole cascade is indicated by numerical andexperimental studies, for some operating conditions suchsectored vane cascade can still remain unstable. READ MORE

  2. 2. Contribution to Numerical and Experimental Studies of Flutter in Space Turbines. Aerodynamic Analysis of Subsonic or Supersonic Flows in Response to a Prescribed Vibratory Mode of the Structure

    University dissertation from ECL

    Author : Hakim Ferria; [2011]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; flutter; space turbine; LRANS computation; flutter measurement; shock wave boundary layer interaction; blisk; cut-on cut-off condition; interblade phase angle; combined modes;

    Abstract : Modern turbomachines are designed towards thinner, lighter and highly loaded blades. This gives rise to increased sensitivity to flow induced vibrations such as flutter, which leads to structure failure in a short period of time if not sufficiently damped. READ MORE

  3. 3. Improved Flutter Prediction for Turbomachinery Blades with Tip Clearance Flows

    University dissertation from Stockholm, Sweden : KTH Royal Institute of Technology

    Author : Tianrui Sun; KTH.; [2018]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Steam turbine; Flutter; Aeroelastic stability; Tip clearance flow; Detached-Eddy Simulation; Energiteknik; Energy Technology;

    Abstract : Recent design trends in steam turbines strive for high aerodynamic loading and high aspect ratio to meet the demand of higher efficiency. These design trends together with the low structural frequency in last stage steam turbines increase the susceptibility of the turbine blades to flutter. READ MORE

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

    University dissertation from Stockholm : KTH Royal Institute of Technology

    Author : Mauricio Gutierrez Salas; KTH.; [2018]
    Keywords : 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; Energiteknik; Energy Technology;

    Abstract : 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. READ MORE

  5. 5. Experimental Investigation of Three-Dimensional Mechanisms in Low-Pressure Turbine Flutter

    University dissertation from Stockholm : KTH Royal Institute of Technology

    Author : Damian Vogt; KTH.; [2005]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Life sciences and physical sciences; turbomachinery; flutter; aeroelastic instability; aeroelastic testing; CFD; linearized unsteady numerical method; 3D aerodynamic effects; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP;

    Abstract : The continuous trend in gas turbine design towards lighter, more powerful and more reliable engines on one side and use of alternative fuels on the other side renders flutter problems as one of the paramount challenges in engine design. Flutter denotes a self-excited and self-sustained aeroelastic instability phenomenon that can lead to material fatigue and eventually damage of structure in a short period of time unless properly damped. READ MORE