The NATO Advanced Study Institute "Flow and Transport Processes in
Complex - structed Geometries: from cities and vegetative canopies to
engineering problems" was held in Kyiv, Ukraine in the period of May 4 -
15, 2004. This book based on the papers presented there provides an
overview of this new area in ?uid mechanics and its app- cations that
have developed over the past three decades. The subject, whose origins
lie both in theory and in practice, is now rapidly developing in many
directions. The focus of applied ?uid mechanics research has steadily
been shifting from - gineering to environmental applications. In both
?elds there has been great interest in the study of ?ows around
obstacles; initially single isolated obstacles, and then groups,
together with the e?ects of nearby resistive surfaces, such as the walls
of a pipe, the ground or a free surface in hydraulics. Simpli?ed
theoretical analysis began with studies of axisymmetric and cylind- cal
free-mounted bodies. However other methods had to be used for
quantifying the complete ?ow ?elds past arbitrary blu? bodies, either by
using experiments or, when powerful computers became available, by
direct calculation and solution of the full equations of ?uid dynamics.
In most practical cases the Reynolds numbers are too large to compute
all the small scale eddy motions which therefore have to be described
statistically.