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Criteria for evaluating the energy
efficiency of heat addition upstream of
the body in a supersonic gas flow are
obtained. Based on the functional
objectives of flying vehicles and the
thermodynamic model of the process,
estimates are obtained for missile- and
aircraft-type vehicles. The minimum Mach
numbers at which heat addition upstream
of the body is reasonable are evaluated.
The increase in the flight range in the
cruising regime for an aircraft-type
vehicle and on the active trajectory for
a missile-type vehicle is evaluated.
Estimates for fuel economy in launching
an aerospace plane into an Earth orbit
are given. It is shown that a
significant part of the fuel should be
spent on producing energy for gas
heating in order to obtain a noticeable
effect. The minimum necessary
"efficiency" of conversion of the fuel
energy into the gas-heating energy is
evaluated.

The problem is solved using parabolized
equations of stability for three-
dimensional perturbations of a
compressible boundary layer on a flat
plate. Nonlinearity is taken into
account by quadratic terms that are most
significant in estimates of the viscous
critical layer of the stability theory.
These terms are determined by the total
field of two acoustic perturbations, and
the equations become linear and
inhomogeneous. The calculations are
performed for one acoustic wave being
stationary in the reference system
fitted to the plate for Mach numbers
M=2;5. Solutions are presented, which
are identified very accurately with
Tollmien-Schlichting waves at a rather
large distance from the plate edge.

Based on the laws of conservation of
mass, momentum, and energy, equations of
dynamics of multiphase systems, which
are gas mixtures with hollow
microspheres with selectively permeable
shells, are obtained under the
assumption of quasi<!dash!>steadiness of
the process offilling the microspheres
by the gas. Acoustic characteristics of
the system composed of a uniform gas and
hollow permeable microspheres are
studied using a simplified (one-velocity
and one-temperature)model. The frequency
dependences of velocity and damping
coefficient of sound are determined with
regard for gas density
(pressure)relaxation inside the
microspheres. P. 69-75

Results of experimental studies are presented on relaminarization of a supersonic turbulent boundary layer behind an expansion fan for a free- stream Mach number M_∞=4 within a range of Reynolds numbers Re₁ = 8

Disturbances produced by external flow
vorticity in a supersonic boundary layer
are studied. It is shown that both
vortical and nonvortical waves play an
important role. The calculations are
performed for subsonic and supersonic
flows for a Mach number M=2. P. 83-89

Calculation results and an approximate
description of the mean velocity of
vibrational motion in a medium with drag
proportional to velocity are presented
as a function of various parameters
characterizing the system. P. 90-92

Thermal and hydrodynamic processes that
occur during impingement of a liquid
metal drop onto a multilayered substrate
are numerically studied. The
mathematical model is based on the
Navier-Stokes equations for an
incompressible liquid and on substrate
and drop heat-transfer equations that
take into account the surface-tension
forces and metal solidification. The
effect of the impact velocity, initial
drop diameter, metal overheating, and
temperature and thermophysical
characteristics of the substrate on the
morphology of the solid drop, its
height, contact-spot diameter, and total
solidification time was examined
numerically. The simulation results are
found to be in satisfactory agreement
with experimental data. P. 93-102

A model of spontaneous crystallization
of a thin melted metal layer brought
into contact with a massive substrate is
proposed. With invoking the Kolmogorov
composite crystallization theory, the
model allows one to predict the size
distribution of crystallites across the
layer, which provides a possibility of
controlling the microstructure of the
solidifying layer through a proper
choice of substrates. P. 103-108

The paper describes an experimental
study of thermal fluctuations during
transition from bubble to film boiling
of water on a wire heater and
fluctuations of the shape of a
superheated liquid jet discharged from a
high-pressure vessel. It is found that
for a heat-transfer crisis on the wire
heater and for intense volume boiling of
the superheated liquid jet, the
fluctuation power spectrum has a low-
frequency component (flicker noise)that
diverges under the law 1/f. This effect
is due to nonequilibrium phase
transitions in the system<!colon!> the
heat<!dash!>transfer crisis during
transition from bubble to film boiling
and a flow crisis during boiling of the
superheated liquid jet. P. 109-113

A study was performed of methods for
controlling thermal regimes in a spatial
supersonic flow around a blunt body with
the simultaneous use of gas injection
from the surface of the porous bluntness
and heat flow in the shell material. The
effect of the nonisothermicity of the
shell wall on the heat-and mass-transfer
characteristics in the boundary layer
was taken into account by solution of
the problem in a conjugate formulation.
It is shown that heat conducting
materials can be used to advantage to
reduce the maximum temperatures in the
screen zone. P. 114-119