Search for dissertations about: "linear eddy model"

Showing result 11 - 15 of 29 swedish dissertations containing the words linear eddy model.

  2. 11. Modelling the transient response of windings, laminated steel coresand electromagnetic power devices by means of lumped circuits : With special reference to windings with a coaxial insulation system

    Author : Pär Holmberg; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Physics; Transient response; frequency response; electromagnetic transient analysis; circuit modeling; eddy currents; skin effect; windings; coils; magnetic cores; cables; electric machines; rotating electric machines; transformers; Fysik; Physics; Fysik; Electricity; Esp The Study Of Transients and Discharges; elektricitetslära; ssk studiet av transienter och urladdning;

    Abstract : Electromagnetic transients impinging on electromagnetic power devices - such as electric machines, transformers and reactors - can stress the design severely. Thus the magnitudes of the transients are often decisive for the design of the devices. Further, the operation of a device can be transient in itself. READ MORE

  4. 12. Unsteady Numerical Simulations and Reduced-Order Modelling of Flows around Vehicles

    Author : Jan Östh; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Reduced-Order Modelling; Numerical Simulations; Large Eddy Simulation; Vehicle Aerodynamics;

    Abstract : In this thesis several simulations have been carried out aimed at improving the knowledge of vehicle aerodynamics and improving the flow around vehicles with respect to theaerodynamic drag. Five flows around different simplified vehicle models have been considered in five appended publications. READ MORE

  5. 13. Numerical methods for load and response prediction for use in acoustic fatigue

    Author : Johan Nilsson; Byggnadsmekanik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Acoustic fatigue; Sonic fatigue; Computational Fluid Dynamics; Large Eddy Simulation; Finite Element Method; Random response analysis; Separated flow; High Re; Backward-facing step; Fence flow; Aircraft; Proper Orthogonal Decomposition; Acoustic fatigue; Sonic fatigue; Computational Fluid Dynamics; Large Eddy Simulation; Finite Element Method; Random response analysis; Separated flow; High Re; Backward-facing step; Fence flow; Aircraft; Proper Orthogonal Decomposition;

    Abstract : Acoustic fatigue can occur in structural elements of an aircraft exposed to very high sound pressures. To deal with acoustic fatigue, mainly empirical methods have been applied and often late in the design phase. Current design guidelines have three main limitations. First, they do not say anything about the load intensities. READ MORE

  6. 14. CFD of Duct Acoustics for Turbocharger Applications

    Author : Emma Alenius; Mats Åbom; Laszlo Fuchs; Federico Piscaglia; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Aero acoustics; Large Eddy Simulation; IC-engines; 1D models; turbocharger; orifice plate; Acoustics; Akustik; Fluid mechanics; Strömningsmekanik;

    Abstract : The search for quieter internal combustion engines drives the quest for a better understanding of the acoustic properties of engine duct components. In this work the main focus is the turbocharger compressor and a discussion of turbocharger acoustics and earlier work within the area is presented, giving an insight into its sound generating mechanisms and the damping effect it has on pressure pulses, i. READ MORE

  7. 15. 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