Search for dissertations about: "Q3D"

Found 3 swedish dissertations containing the word Q3D.

  2. 1. Multi-objective CFD-based design method for axial compressors

    Author : Lars R Ellbrant; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Q3D; Turbomachinery; Design; Meta-modeling; Optimization; CFD; Validation; Compressor; Transonic;

    Abstract : Economic aspects such as reducing specific fuel consumption and ever growing environmental requirements on emissions and perceived noise levels are the major incentives in the pursuit to improve aircraft engines. The overall efficiency of the engine is a combination of propulsive efficiency and thermal efficiency. READ MORE

  4. 2. 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

  5. 3. EMI from Switched Converters – Simulation Methods and Reduction Techniques

    Author : Andreas Henriksson; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; state space methods; EMI; semiconductor device modeling; diode reverse recovery; diode modeling; conducted emissions; Semiconductor device measurements; DC DC converters;

    Abstract : In this thesis, the conducted EMI from switched power converters has been analyzed using various existing models, own-derived models as well as measurements. The ingoing passive components in a switching converter have been modeled with respect to their high frequency behavior and the static and dynamic behavior of the active semiconductors has been analyzed. READ MORE