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Showing result 1 - 5 of 15 swedish dissertations matching the above criteria.

  2. 1. 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

  4. 2. Turbomachinery Aeroacoustic Calculations using a Time Domain Chorochronic Method

    Author : Martin Olausson; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Rotor Stator interaction; Fan-Noise; Time lag; Chorochronic; Nonlinear; Computational Aeroacoustics;

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

  5. 3. 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

  6. 4. Modeling of Unsteady Flow Effects in Throughflow Calculations

    Author : Magnus Stridh; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; rotor-stator interaction; mixing-plane; linear Navier-Stokes; cascade; turbomachinery; transport equation; Linear harmonic; compressor; throughflow; turbine; Deterministic stress terms;

    Abstract : In this work an evaluation of a deterministic stress transport model and a linearized Navier-Stokes harmonic approach for including unsteady effects in the steady mixing-plane computations of a multistage transonic compressor has been performed. The results of these two models are compared with those of time-average time-accurate solutions. READ MORE

  7. 5. Modeling Unsteady flow Effects in 3D Throughflow Calculations

    Author : Magnus Stridh; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; throughflow; turbomachinery; mixing-plane; rotor-stator interaction; cascade; Deterministic stress terms; Linear harmonic; compressor; preconditioned GMRES; Unsteady; linear Navier-Stokes; turbine;

    Abstract : The flow field in a transonic multistage compressor is compressible, three-dimensional and highly unsteady and can be predicted in principle by the exact time-accurate Navier-Stokes equations. The high Reynolds number encountered in multistage turbomachinery together with the wall-bounded nature of the flow environment however prevent the use of DNS to solve the exact N-S equations. READ MORE