Near-wall turbulence & porous walls
This part contains documents related to my work on near-wall
turbulence, its structure(s) and possible control, initiated during
the years 1998-1999 while being at Universidad Politécnica de Madrid
under supervision of Javier Jimenez.
- "The instability of streaks in near-wall turbulence". This CTR
Research
Brief
from 1998 (pp. 155-170) by G. Kawahara, J. Jiménez,
M. Uhlmann and A. Pinelli describes a simple linear model for the
initial phase of streak break-up.
- "Fully developed laminar flow in a plane channel with constant
cross flow". Simple analytical expression for the variation of the
friction coefficient as a function of blowing/suction is derived
here.
- "Estimation of the Persistence of the Effect of a Porous
Surface on the Adjacent Turbulent Flow". We describe the transient
after an initially porous wall in plane channel flow is suddenly
made impermeable in this compressed postscript
document.
- "A modified plane channel code for flow with a spatially varying
pressure gradient". In this
report
we (A. Pinelli & M. Uhlmann) describe how a streamwise variation of
the mean pressure can be simulated in the setting of a "classical"
spectral code [16].
- "Plane channel flow simulation over porous walls" by J.
Jiménez, A. Pinelli, M. Uhlmann (Technical Note ETSIA
MF-9809, U. Politecnica Madrid) as of 1998. This
document
describes the numerical method, physical parameters and results of
our simulation of flow over Darcy-porous boundaries in
detail. Contained is the write-up of our new Fourier/B-spline
method.
- "Linear stability analysis of turbulent channel flow including
porous walls" by J. Jiménez, G. Kawahara, A. Pinelli, M.
Uhlmann (Technical Note ETSIA MF-9811, U. Politecnica Madrid) as of
1998. The
report
contains an account of the numerical
method - based upon a B-spline Galerkin approach - and the results
of our stability analysis of a simple model for buffer-layer streaks
in plane channel flow. This complementary
report
documents the way by which turbulent background fluctuations are
incorporated, similar as proposed in [17].
- Animated visualizations of coherent structures in turbulent
channel flow over a porous wall are available in MPEG format (in
arguably low quality).
- "The Influence Of Wall-Porosity Upon The Near-Wall Turbulence
Dynamics" by M. Uhlmann, A. Pinelli, J. Jiménez and G. Kawahara
(Proc. 8th ETC, Barcelona, 2000, pp. 463-466). This conference
contribution
sums up our findings regarding the flow over porous walls. There is
even a snapshot from the
conference reception.
- "Turbulent shear flow over active and passive porous
surfaces" by J. Jiménez, M. Uhlmann, A. Pinelli and G. Kawahara
has appeared in J. Fluid Mech., 442:89-117, 2001.
markus.uhlmann AT kit.edu
