Sökning: "INSTABILITY"

Visar resultat 1 - 5 av 853 avhandlingar innehållade ordet INSTABILITY.

  1. 1. Instability in Settling Fibres : A Numerical Study

    Författare :Feng Zhang; Anders A. Dahlkild; Fredrik Lundell; Mark Martinez; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; bre suspensions; sedimentation; instability; mixture model; point-particle mode;

    Sammanfattning : Sedimenting suspensions exist in a varity of natural phenomena and industrial applications. It is already observed in experiments that the dilute fibre suspensions experience a concentration instability under gravity at low Reynolds numbers. Initially well-mixed suspensions become inhomogeneous and anisotropic due to this instability. LÄS MER

  2. 2. Experimental study of the rotating-disk boundary-layer flow

    Författare :Shintaro Imayama; Henrik Alfredsson; Rebecca Lingwood; Benoît Pier; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fluid mechanics; boundary layer; rotating disk; laminar-turbulent transition; convective instability; absolute instability; secondary instability; crossflow instability; hot-wire anemometry.;

    Sammanfattning : Rotating-disk flow has been investigated not only as a simple model of cross flow instability to compare with swept-wing flow but also for industrial flow applications with rotating configurations. However the exact nature of laminar-turbulent transi- tion on the rotating-disk flow is still major problem and further research is required for it to be fully understood, in particular, the laminar-turbulent transition process with absolute instability. LÄS MER

  3. 3. Direct numerical simulations of the rotating-disk boundary-layer flow

    Författare :Ellinor Appelquist; Philipp Schlatter; Henrik Alfredsson; Rebecca Lingwood; Christopher Davies; KTH; []
    Nyckelord :Fluid mechanics; boundary layer; rotating disk; laminar-turbulent transition; convective instability; absolute instability; secondary instability; crossflow instability; direct numerical simulations; Teknisk mekanik; Engineering Mechanics;

    Sammanfattning : This thesis deals with the instabilities of the incompressible boundary-layer flow that is induced by a disk rotating in otherwise still fluid. The results presented are mostly limited to linear instabilities derived from direct numerical simulations (DNS) but with the objective that further work will focus on the nonlinear regime, providing greater insights into the transition route to turbulence. LÄS MER

  4. 4. Theory of economic development : nonlinearity, instability and non-equilibrium

    Författare :Wei-Bin Zhang; Umeå universitet; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; economic growth and development; instability; structural change; bifurcation; non-equilibrium; centralization and decentralization; business cycle; the standard neoclassical growth model; growth rate; interest rate; inflation rate; choice of techniques; endogenous technological change;

    Sammanfattning : The objective of this study is to propose an economic development theory within the framework of input-output systems and neoclassical economics. This study consists of nine chapters which are arranged in the following manner:In Chapter I, we discuss development problems, define some essential concepts, and provide a general historical sketch of economic growth theory. LÄS MER

  5. 5. Radar Signatures of Auroral Plasma Instability

    Författare :Nicola Schlatter; Nickolay Ivchenko; Anja Stromme; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ionosphere; Particle Precipitation; Instability; Plasma Turbulence; Fysik; Physics;

    Sammanfattning : Incoherent scatter radars are powerful ground based instruments for ionospheric measurements. By analysis of the Doppler shifted backscatter spectrum, containing the signature of electrostatic plasma waves, plasma bulk properties are estimated. LÄS MER