Sökning: "nonlinear perturbation"
Visar resultat 21 - 25 av 35 avhandlingar innehållade orden nonlinear perturbation.
21. Steady waves in local and nonlocal models for water waves
Sammanfattning : We study the steady Euler equations for inviscid, incompressible, and irrotational water waves of constant density. The thesis consists of three papers. The first paper approaches the Euler equations through a famous nonlocal model equation for gravity waves, namely the Whitham equation. LÄS MER
22. An experimental investigation of disturbance growth in boundary layer flows
Sammanfattning : This thesis deals with the early stages of transition to turbulence in two different baseflows, namely the Falkner-Skan-Cooke boundary layer (FSC) and the asymptotic suction boundary layer (ASBL). Grid-generated turbulence is studied in order to characterise the isotropy levels, free-stream turbulence levels and characteristic length scales that will be present in the receptivity study. LÄS MER
23. A Linearized Euler Method for Unsteady Flow in Axial-Flow Turbomachines
Sammanfattning : A linear Euler method for analysing unsteady inviscid compressible quasi three- dimensional flows in oscillating cascades is developed. It is applicable to both blade flutter and forced response problems. LÄS MER
24. Spectra and Dynamics of Excitations in Long-Range Correlated Structures
Sammanfattning : Vad karaktäriserar en kristall? Svaret på denna till synes enkla fråga blir kanske att det är en anordning av atomer uppradade i periodiska mönster. Så ordnade strukturer kan studeras genom att det uppträder så kallade Braggtoppar i röntgendiffraktionsmönstret. LÄS MER
25. Sawteeth and other Transport Phenomena Induced by Ex-drifts in Tokamaks
Sammanfattning : Electric fields and the concomitant ExB-drift play a prominent role in many plasma physics phenomena in Tokamaks. Several issues relevant for fusion research and related to the ExB-driven transport, are addressed in the present thesis. LÄS MER