Sökning: "modeshapes"

Hittade 4 avhandlingar innehållade ordet modeshapes.

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

    Detta är en avhandling från Stockholm : KTH Royal Institute of Technology

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

    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

  2. 2. Concepts for Power System Small Signal Stability Analysis and Feedback Control Design Considering Synchrophasor Measurements

    Detta är en avhandling från Stockholm : KTH Royal Institute of Technology

    Författare :Yuwa Chompoobutrgool; KTH.; [2012]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wide-area damping control; inter-area oscillations; power system stabilizers; PMU; Järnvägsgruppen - Elsystem; Järnvägsgruppen - Elsystem;

    Sammanfattning : In the Nordic power network, the existence of poorly damped low-frequency inter-area oscillations (LFIOs) has long affected stability constraints, and thereby, limited power transfer capacity. Adequate damping of inter-area modes is, thus, necessary to secure system operation and ensure system reliability while increasing power transfers. LÄS MER

  3. 3. 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

    Detta är en avhandling från ECL

    Författare :Hakim Ferria; [2011]
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

  4. 4. Flutter in sectored turbine vanes

    Detta är en avhandling från Stockholm : Energiteknik

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

    Sammanfattning : 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. LÄS MER