vi
developed only in
a
local statement. i.e.
or
within
a
rath
r
small
time interval
[I811
or
at
rnther limited initial data
L1791.
A
glob-
al
behaviour of the solution ha.a been investigated only for the case
of one-dimensional motion. The results for one-dimensional lJavier-
Stokes equations being of
a
global character represent
a
main con-
tent
of
Chapter
2.
The third chapter considers the model of
a
nonhomogeneous vis-
cous incompressible liquid. Different Aspects of the theory of equa-
tions of homogeneous viscous incompressible liquid have been pre-
sented in the book by 0.A.Ladyzhenskaya
L88J.
Interest to the model
of inhomogeneous liquid
is
conditioned by
its
si,mificance for ap-
plied fields of hydrodynamics, such
as
oceanology and hydrology.
It
should be noted that
teking
into account heterogeneity brings
some peculierities to
a
theoretical analysis, which are connected
with
an
additional nonlinearity of equations. Besides generalization
of the well-known theorems from
88
to
the case of nonhomogeneous
liquid, the pew statements
of
boundary value problems with one-side
restrictions are analyzed. In addition, the results
of
studying the
model of inbomogeneous two-component liquid taking into account dif-
fusion
and
the models
of
a
medium having internal
degrees of freedon
Eire considered.
an ideal incompressible liquid.
It
is
necessary
to
note that the
problem of correctness of boundary vc?lue problems for u%ler equa-
tions
is
nontrivial even the studies in local statement. The funda-
mental results.in the theory of equations of ideal liquid belong
to N.M.Gunter
1421
and
L.Lichtenstein
11771.
In these works the
CRBCS
have been considered when the
flow
region boundaries are
ab-
sent
or
are characteristic surfaces for Euler equations, i.e. vhen
the liquid occupies the whole space
or
when the vessel has imperme-
able
walln.
Nore general boundarj-valae problems which a2pear when
considering the liquid motion in
a
given region are cliffwent in
principle: in that section of the
flow
regior? boundary where the
liquid flow-in takes place,
it
is
necessary
to
prescribe
the addi-
tional boundary conditions. 'I'he problem of flowine through
a
given
region
'FIBS
first considered by N.E.:Cochin
30
in
a
model statement
when the values of velocity vortex were prescribed
as
additional
boundary conditions in th.e section
of
flowing-in. The problem for
which the whole velocity vector
is
prescribcd in the floming-in sec-
tion
is
nore natural. from the standpoint of physics. However, the
attempts to justify the correctness
of
such
n
statement have been
unsuccessful
for
a
long
time. The main result of Chapter
IV
consists
in proovinz the solvability
of
the problem
of
flowing-in
jvst
in
the above-xentioned physical statement. Eesides, other variants of
correct statements of the flowing-through problem are presented.
In particular,
it
has been shown that in the problem studied
by
B.E.Kochin the whole velocity vortex vector ccvlnot be arbitrarily
prescribed,
it
can be done
for
only
its
tangential components.
tions for two unmixing incompressible liquids in
a
porous medium.
The appearance of this model and the interest to be genernted
anions
matheme.tici,uls In
it
are conditioned by elaborating tine method of
oil forcing out
by
pumping water
or
special solutions into tlie oil
layer. The main mathematica,l peculiarity
of
the above
model
is
that
it
is
reduced to the system of
two
second-order equations, one being
elliptic and the second being parabolic. The lat,ler may degenerata
to
the first-order e uation at definite values of the required
30-
lution. The correctness of
bounda;y
value problems for equations of
of multi-phase liquid filtration has been analyzed recently,
and
the
most
complete results in this area have been obta.ined by V.N.Xona-
The fourth chapter investigates the classical Ihler model for
Chapter
V
is
devoted
to
the investigation of filtration equa-