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Showing result 1 - 5 of 11 swedish dissertations matching the above criteria.

2. 1. Flutter in sectored turbine vanes

   Author : Olga V. Chernysheva; KTH; []
   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

4. 2. Numerical simulation of viscous compressible flows applied to turbomachinery blade flutter

   Author : L. D. Gunnar Sidén; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; unsteady; flutter; turbine; aeroengine; turbomachinery; numerical method; oscillating; Navier-Stokes; finite volume; viscious; finite element; turbulent; fan; aeroelastic; vibration; compressor; stall;

   Abstract : .... READ MORE

5. 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

   Author : Hakim Ferria; Pascal Ferrand; Torsten Fransson; François Moyroud; France Ecole Centrale de Lyon Laboratoire de Mécanique des Fluides et d'Acoustique; []
   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

6. 4. Improved Flutter Prediction for Turbomachinery Blades with Tip Clearance Flows

   Author : Tianrui Sun; Andrew R. Martin; Paul Petrie-Repar; Mihai Mihaescu; KTH; []
   Keywords : 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

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

   Author : Mauricio Gutierrez Salas; Björn Laumert; Paul Petrie-Repar; Damian Vogt; Carlos Martel; KTH; []
   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; Energy Technology; Energiteknik;

   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