Sökning: "Aeroelastic stability"

Visar resultat 1 - 5 av 12 avhandlingar innehållade orden Aeroelastic stability.

  1. 1. 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

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

    Författare :Tianrui Sun; Andrew R. Martin; Paul Petrie-Repar; Mihai Mihaescu; KTH; []
    Nyckelord :Steam turbine; Flutter; Aeroelastic stability; Tip clearance flow; Detached-Eddy Simulation; Energiteknik; Energy Technology;

    Sammanfattning : 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. LÄS MER

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

    Författare :Damian Vogt; Torsten Fransson; Robert Kielb; KTH; []
    Nyckelord :Life sciences and physical sciences; turbomachinery; flutter; aeroelastic instability; aeroelastic testing; CFD; linearized unsteady numerical method; 3D aerodynamic effects; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP;

    Sammanfattning : 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. LÄS MER

  5. 4. Stability and transition in pitching wings

    Författare :Prabal Negi; Dan Henningson; Ardeshir Hanifi; Philipp Schlatter; Olivier Marquet; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Flyg- och rymdteknik; Aerospace Engineering; Vehicle and Maritime Engineering; Farkostteknik;

    Sammanfattning : The aeroelastic stability of airplanes is one of the most important aspects of airplane design. Flutter or divergence instabilities arising out of the interaction of fluid forces and structural elasticity must be avoided by design or through the limitation of the flight envelope. LÄS MER

  7. 5. On Aerodynamic and Aeroelastic Modeling for Aircraft Design

    Författare :Mikaela Lokatt; Ulf Ringertz; David Eller; Holger Mai; KTH; []
    Nyckelord :viscous-inviscid interaction model; laminar flow wing; aerodynamics; aeroelasticity; aircraft design; Flyg- och rymdteknik; Aerospace Engineering;

    Sammanfattning : The work presented in this thesis was performed with the aim of developing improved prediction methods for aerodynamic and aeroelastic analysis to be used in aircraft design. The first part of the thesis concerns the development of a viscous-inviscid interaction model for steady aerodynamic predictions. LÄS MER