Sökning: "plane Couette flow"

Hittade 5 avhandlingar innehållade orden plane Couette flow.

1. 1. Stability of plane Couette flow and pipe Poiseuille flow

   Författare :Per-Olov Åsén; Gunilla Kreiss; Jonathan Goodman; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hydrodynamic stability; plane Couette flow; pipe Poiseuille flow; direct numerical simulations; resolvent; Fluid mechanics; Strömningsmekanik;

   Sammanfattning : This thesis concerns the stability of plane Couette flow and pipe Poiseuille flow in three space dimensions. The mathematical model for both flows is the incompressible Navier--Stokes equations. Both analytical and numerical techniques are used. We present new results for the resolvent corresponding to both flows. LÄS MER

3. 2. Stability results for viscous shock waves and plane Couette flow

   Författare :Mattias Liefvendahl; KTH; []
   Nyckelord :nonlinear stability; shock waves; Couette flow; Chebyshev spectral method; resolvent estimates; threshold amplitudes;

   Sammanfattning : .... LÄS MER

4. 3. Direct numerical simulation of turbulent flow in plane and cylindrical geometries

   Författare :Jukka Komminaho; KTH; []
   Nyckelord :turbulence; plane Couette flow; pipe flow; laminar-turbulent transition; direct numerical simulation; spectral methods;

   Sammanfattning : This thesis deals with numerical simulation of turbulentflows in geometrically simple cases. Both plane and cylindricalgeometries are used. The simplicity of the geometry allows theuse of spectral methods which yield a very high accuracy usingrelatively few grid points. A spectral method for planegeometries is implemented on a parallel computer. LÄS MER

5. 4. A proof of a resolvent estimate for plane flow by new analytical and numerical techniques

   Författare :Per-Olov Åsén; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Datalogi; Datalogi; Computer science; Datalogi;

   Sammanfattning : This thesis concerns stability of plane Couette flow in three space dimensions for the incompressible Navier-Stokes equations. We present new results for the resolvent corresponding to this flow. Previously, analytical bounds of the resolvent have been derived in parts of the unstable half-plane. LÄS MER

7. 5. Optimisation and control of shear flows

   Författare :Antonios Monokrousos; Dan S. Henningson; Laurette Tuckerman; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; shear flows; flow control; optimal disturbances; Lagrange method; transition to turbulence; non-linear dynamics; Engineering mechanics; Teknisk mekanik;

   Sammanfattning : Transition to turbulence and flow control are studied by means of numerical simulations for different simple shear flows. Linear and non-linear optimisation methods using the Lagrange multiplier technique are employed. LÄS MER