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Some progress on Prandtl's system. / CUHK electronic theses & dissertations collectionJanuary 2003 (has links)
Chu Shun Yin. / "August 2003." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (p. 55-60). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.
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An experimental study of turbulent natural convection in water and mercuryJain, Ashok January 2011 (has links)
Digitized by Kansas Correctional Industries
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Convex optimization-based resource scheduling for multi-user wireless systemsZarakovitis, Charilaos C. January 2011 (has links)
No description available.
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Surface and liquid crystal interlayer interactions : characterizations and applications /Murauski, Anatoli. January 2007 (has links)
Thesis (Ph.D.)--Hong Kong University of Science and Technology, 2007. / Includes bibliographical references (leaves 128-132). Also available in electronic version.
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Turbulence structure within an inclined laboratory convection tankNance, Jon D. 09 February 1989 (has links)
A baroclinic, convective mixed-layer was modeled, using
water, in a laboratory convection tank identical to that
used in the free convection study of Deardorff and Willis
(1985). Baroclinicity and mean-flow shearing were achieved
by tilting the tank by an angle of 1O⁰. The resulting
mechanical-production rate of turbulence kinetic energy was
comparable in magnitude to the buoyancy-production rate at
mid-levels within the mixed-layer.
Velocities were obtained by taking time-lapse
photographs of neutrally-buoyant oil droplets suspended in
the mixed-layer fluid. Variances and other statistical
descriptors of the turbulence obtained from these
velocities are presented in comparison to the free
convection results of Deardorff and Willis (1985). The
deviation of the present results from those of Deardorff
and Willis (1985) are assumed to be related to the effects
of mean-flow shearing and are explained wherever possible
with the aid of an appropriate kinetic energy budget
(kinetic energy, here, refers to the kinetic energy of the
turbulence and is not to be confused with the kinetic
energy of the mean-flow).
The results indicate that a maximum in downstream
horizontal kinetic energy at mid-levels within the mixed layer
was generated by shear-production and, also, by
conversion from vertical kinetic energy. In the lower
mixed-layer, vertical kinetic energy was amplified by a
mechanical-production term associated with the divergence
of the mean vertical velocity. Total turbulence kinetic
energy, normalized by the square of the convective velocity
scale, was much larger at mid-levels than in Deardorff and
Willis (1985) due to mechanical-production which is not
accounted for by simple mixed-layer scaling. Horizontal
turbulence structure was predominately controlled by
convection while vertical turbulence structure was
significantly altered by mean-flow shearing. / Graduation date: 1989
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A nonlocal mixing formulation for the atmospheric boundary layerFrech, Michael C. 17 December 1993 (has links)
A two-scale approach for the turbulent mixing of momentum in an unstable
stratified boundary layer is proposed in an attempt to eliminate existing inconsistencies
between parameterized mixing of heat and momentum. The parameterization
of the large eddy stress is suitable for simple boundary layer models where computational
efficiency is important. We test the proposed formulation in a simple
boundary layer model and compare predicted momentum profiles with Lidar mean
momentum profiles from FIFE 1989. We examine the sensitivity of the proposed
mixing scheme to baroclinicity. While the proposed two-scale approach is able to
better predict observed conditions of well mixed momentum profiles, the complexity
of momentum transport in baroclinic conditions is not well approximated. / Graduation date: 1994
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Turbulent structure in the bora and stable boundary layerFrank, Helmut P. 03 April 1986 (has links)
An eigenvector analysis of the velocity-temperature correlation
matrix is applied to clear-air turbulence measured by aircraft in the
Bora. The eigenvectors are identified with the main eddies of the
turbulence. This study attempts to infer the three-dimensional
structure of these eddies. The results are compared with turbulent
structures in the stable boundary layer. The turbulence in the
strongly stratified boundary layer appears to be dominated by double
roller eddies with their axes of rotation tilted in the shear direction.
The clear-air turbulence shows a larger variety of motion
types. / Graduation date: 1986
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Parameterization of shallow convection in the boundary layerChu, Cheng-tsong 23 September 1986 (has links)
A shallow convection scheme is derived from several data sets
(BOMEX, GATE, AMTEX, BLX83) and developed for the OSU 1-D boundary
layer model. Results of the model structure and characteristics of
the saturation point (SP) profile are compared against the constant
cloud diffusivity scheme of Tiedtke (1983) and the ECMWF boundary
layer parameterization scheme.
The results indicate that the primary mechanism that transports
moisture away from the lower boundary layer is the boundary layer
turbulent flux and that the boundary turbulent mixing alone is
capable of maintaining an apparent moisture source near the
inversion. While the sensible heat flux over ocean becomes quite
small after a few hours of model simulation, the virtual heat flux
remains positive and the boundary layer remains in the unstable
regime. / Graduation date: 1987
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Numerical simulation of planetary boundary-layer evolution and mesoscale flow over irregular terrain under daytime heating conditionsUeyoshi, Kyozo 01 March 1985 (has links)
The influence of irregular terrain on the evolution of the daytime
planetary boundary layer (PBL) and meso-β scale dry circulations is
studied using two three-dimensional hydrostatic σ-coordinate models
with different approaches for the PBL parameterizations; the 4-layer
model uses the mixed-layer (bulk-layer) approach, while the 7-layer
model adopts the eddy-diffusivity (multi-layer) approach. Numerical
experiments are carried out under the conditions of a dry, sunny summer
day with moderate prevailing westerly winds blowing over gently sloping
idealized hills in a domain of 150 km on a side. The results from the
two models are compared and their performances are evaluated.
The behaviors of the mean PBL depth and inversion strength are
analytically described using a simple one-point mixed-layer model.
Counterclockwise rotation of the mean PBL winds with time observed in
both model results can be explained only when the non-zero momentum
flux at the PBL top is taken into account. However, stresses
associated with entrainment at the PBL top are not sufficient to pull
the cold air out of the valleys so as to result in breakup of the
early morning stable layer, as is suggested in a previous study.
The regions of weak winds that persist in the morning PBL are
attributed largely to the baroclinic effect of horizontal variations of
potential temperature θ in the PBL, while the effect of surface drag is
quite small in these areas. Significant differences in the flow
patterns near the surface in two results suggest the importance of the
local pressure gradient force associated with terrain irregularities.
The effect of horizontal θ advection is also significant in helping
reduce the PBL θ anomalies and promote breakup of the stable layer.
The well-mixed assumption generally applies quite well to the
development of the θ profiles, while for momentum it seems valid only
during the peak of convective mixing and the eddy-diffusivity approach
is probably preferable for a better description of the low-level flows.
The fields of the PBL top height obtained using different procedures
in the two models are found to correspond fairly well to each other.
Mass-flux convergence associated with terrain irregularities and
resulting changes in the wind fields are shown to play a key role in
the midday PBL height patterns. The development of the PBL structure
as revealed by the θ cross sections obtained from either model corresponds
favorably to that indicated by idealized cross sections previously
constructed from observed data. The formation of a region of
mass-flux convergence and accompanying updrafts near the surface on the
leeward side of a mountain, processes which are likely to be important
in terrain-induced cloud initiations, seem to be simulated. / Graduation date: 1985
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Development of a novel balloon-borne optical sonde for the measurement of ozone and other stratopheric trace gases = Entwicklung einer ballongestützten optischen Sonde zur Messung von Ozon und anderen stratosphärischen Spurengasen /Wolff, Mareile. January 2007 (has links)
Thesis (doctoral)--Universität Bremen, 2005. / Includes bibliographical references.137-144).
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