Search for dissertations about: "rotor blade"

Showing result 11 - 15 of 45 swedish dissertations containing the words rotor blade.

2. 11. Modelling Microslip Friction Damping and its Influence on Turbine Blade Vibrations

   Author : Gabor Csaba; A. V. Srinivasan; Linköpings universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Abstract : A common failure mode for turbomachinery is high-cycle fatigue of compressor and turbine blades, due to high dynamic stresses caused by blade vibration resonance within the operating range of the machinery. A large number of engine shut-downs can be explained by blade failure caused by resonance vibration or flutter. READ MORE

4. 12. Turbomachinery Aeroacoustic Calculations using Nonlinear Methods

   Author : Martin Olausson; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Nonlinear; CFD; Time Spectral; CAA; Ffowcs-Williams Hawkings; Broadband; Time lag; Computational Aeroacoustics; Fan-Noise; Rotor-Stator interaction; Buffer layer; Oscillating sphere; Newton-GMRES; Computational Fluid Dynamics; Acoustic analogies; Sponge; Counter-Rotating Propfan; Harmonic Balance Technique; Tone; FWH; Chorochronic periodicity; Hybrid RANS LES;

   Abstract : Noise regulations for aircraft that fly over populated areas are becoming continuously stricter. This in combination with increasing computational capabilities has boosted interest in aeroacoustic computations in the aerospace industry. READ MORE

5. 13. Numerical Investigation of the Aerodynamic Vibration Excitation of High-Pressure Turbine Rotors

   Author : Markus Jöcker; KTH; []
   Keywords : Aeroelasticity; Aerodynamics; Stator-Rotor Interaction; Excitation Mechanism; Unsteady Flow Computation; Forced Response; High Cycle Fatigue; Turbomachinery; Gas-Turbine; High-Pressure Turbine; Turbopump; CFD; Design;

   Abstract : The design parameters axial gap and stator count of highpressure turbine stages are evaluated numerically towards theirinfluence on the unsteady aerodynamic excitation of rotorblades. Of particular interest is if and how unsteadyaerodynamic considerations in the design could reduce the riskofhigh cycle fatigue (HCF) failures of the turbine rotor. READ MORE

6. 14. Calibration and Reduction of Large-Scale Dynamic Models - Application to Wind Turbine Blades

   Author : Majid Khorsand Vakilzadeh; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; maximum likelihood estimator; model reduction; finite element model calibration; Bayesian model calibration; Verification and validation; wind turbine blade; logarithmic least square estimator; large-scale dynamics model; SWPTC;

   Abstract : This thesis investigates the validity of structural dynamics models of wind turbine blades. An outlook on methods for model calibration to make models valid for their intended use is presented in the thesis. The intention is to make the models valid for robust predictions. The model validity is here assessed to be of hierarchical dual level. READ MORE

7. 15. Preliminary Design Investigations for the Selection of Optimum Reaction Degree for 1st Stage of a High Pressure Gas Turbine

   Author : Hina Noor; Torsten Fransson; Konstantinos G. Kyprianidis; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 1D design; aerodynamic design parameters; flow kinematic; thermodynamics; rotor inlet temperature; cooled turbine; reaction degree; flow coefficient; stage loading;

   Abstract : One-dimensional (1D) turbine design calculation phase requires a handful of input data and choice of design parameters to provide the blade flow path geometry along with the flow kinematics and thermodynamics properties at the blade mid-span. The choice of important aerodynamics design parameters namely reaction degree, nozzle guide vane NGV exit flow angle or flow coefficient and stage loading defines the mid-span flow velocity triangles. READ MORE