Search for dissertations about: "transient instability"

Showing result 6 - 10 of 41 swedish dissertations containing the words transient instability.

  2. 6. Time-domain modelling of high-frequency wheel/rail interaction

    Author : Astrid Pieringer; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wheel rail interaction; railway noise; roughness; time domain; frictional instability; discrete irregularities; transient contact; non-Hertzian contact;

    Abstract : The interaction between wheel and rail is the predominant source of noise emission from railway operations in a wide range of conventional speeds. On the one hand, this wheel/rail noise concerns rolling noise and impact noise caused by the vertical interaction excited by roughness and discrete irregularities of the wheel/rail running surfaces, respectively. READ MORE

  4. 7. Numerical studies on flows with secondary motion

    Author : Jacopo Canton; Philipp Schlatter; David Moxey; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nonlinear dynamical systems; instability; bifurcation; flow control; skin-friction reduction; Engineering Mechanics; Teknisk mekanik;

    Abstract : This work is concerned with the study of flow stability and turbulence control - two old but still open problems of fluid mechanics. The topics are distinct and are (currently) approached from different directions and with different strategies. READ MORE

  5. 8. Optimal Control of Boundary Layer Transition

    Author : Markus Högberg; KTH; []
    Keywords : laminar-turbulent transition; transition control; turbulence control; flow control; boundary layer flow; channel flow; optimal control; adjoint equations; Riccati equations; Orr--Sommerfeld--Squire equations; secondary instability; transient gro;

    Abstract : .... READ MORE

  6. 9. Numerical simulation of thermomechanically coupled transient rolling contact - An arbitrary Lagrangian-Eulerian approach

    Author : Andreas Draganis; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; thermomechanical coupling; finite element method; transient analysis; arbitrary Lagrangian--Eulerian; rolling contact; frictional contact;

    Abstract : Numerical simulation of rolling contact serves as an important complement to laboratory and full-scale testing in the endeavour to further the understanding of related physical mechanisms, e.g. the influence of friction on the rolling motion, the thermomechanical interaction, damage phenomena and related modes of failure. READ MORE

  7. 10. Secondary Electromagnetic Radiation Generated by HF Pumping of the Ionosphere

    Author : Lars Norin; Bo Thidé; Savely M. Grach; Bengt Gustafsson; James W. LaBelle; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; space physics; ionospheric modification experiments; plasma turbulence; stimulated electromagnetic emission; ionospheric irregularities; radio waves; parametric processes; thermal parametric instability; transient dynamics; wave-wave interactions; Physics; Fysik;

    Abstract : Electromagnetic waves can be used to transmit information over long distances and are therefore often employed for communication purposes. The electromagnetic waves are reflected off material objects on their paths and interact with the medium through which they propagate. READ MORE