共查询到20条相似文献,搜索用时 15 毫秒
1.
V. A. Levin V. G. Gromov N. E. Afonina 《Journal of Applied Mechanics and Technical Physics》2000,41(5):915-922
The effect of local source of energy in a supersonic flow on the aerodynamic drag and heat transfer of a spherically blunted
body is studied numerically. Calculations are performed on the basis of the Navier-Stokes equations for a thermally equilibrium
model of air. Data on the effect of the intensity and size of the energy source on the wave drag, friction, and heat transfer
are obtained. Particular attention is given to studying the effect of drag reduction by means of a focused heat source. The
gas-dynamic nature of this effect is studied. The limits of drag reduction are estimated, and optimal conditions of heat supply
are determined.
Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 41, No. 5, pp. 171–179, September–October, 2000. 相似文献
2.
S. M. Aulchenko V. P. Zamuraev A. P. Kalinina 《Journal of Applied Mechanics and Technical Physics》2007,48(6):834-839
The possibility of controlling the aerodynamic characteristics of airfoils in transonic flight regimes by means of local pulsed
periodic energy supply is considered. The numerical solution of two-dimensional unsteady equations of gas dynamics allowed
determining the changes in the flow structure near a symmetric airfoil and its aerodynamic characteristics depending on the
magnitude of energy in the case of its asymmetric (with respect to the airfoil) supply. The results obtained are compared
with the calculated data for the flow around the airfoil at different angles of attack without energy supply. With the use
of energy supply, a prescribed lift force can be obtained with a substantially lower wave drag of the airfoil, as compared
with the flow around the airfoil at an angle of attack.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 48, No. 6, pp. 70–76, November–December, 2007. 相似文献
3.
S. M. Aulchenko V. P. Zamuraev A. P. Kalinina 《Journal of Applied Mechanics and Technical Physics》2008,49(6):957-961
The possibility of controlling the aerodynamic characteristics of airfoils in transonic flight regimes by means of one-sided
pulsed-periodic energy supply is studied. Based on the numerical solution of two-dimensional unsteady gas-dynamic equations,
the change in the flow structure in the vicinity of a symmetric airfoil at different angles of attack and the aerodynamic
characteristics of the airfoil as functions of the amount of energy supplied asymmetrically (with respect to the airfoil)
are determined. The results obtained are compared with the data calculated for the flow past the airfoil at different angles
of attack without energy supply. It is found that a given lift force can be obtained with the use of energy supply at a much
better lift-to-drag ratio of the airfoil, as compared to the case of the flow past the airfoil at an angle of attack. The
moment characteristics of the airfoil are found.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 6, pp. 82–87, November–December, 2008. 相似文献
4.
G. N. Dudin 《Fluid Dynamics》1998,33(4):512-518
The influence of intense surface cooling on the parameters of a laminar boundary layer flow on a thin delta wing in a hypersonic
viscous perfect-gas stream is studied for the strong viscous-inviscid interaction regime. The effect of the power-law shape
of the wing cross-section and the wing thickness to boundary-layer displacement thickness ratio on the local and total aerodynamic
characteristics is numerically investigated.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 4, pp. 57–64, July–August, 1998. 相似文献
5.
Transformation of energy and composition of gas mixtures in a collision of rarefied supersonic flows
Transformation of energy and composition of gas mixtures in a convergent flow from a strip source on a cylindrical surface
toward the axis is systematically studied with the use of the direct simulation Monte Carlo method. Information on the influence
of gas-flow rarefaction and system geometry on the temperature and concentration of the heavy gas in a dense cloud formed
on the axis is obtained. The use of convergent supersonic flows is demonstrated to offer new possibilities for research in
the field of physical gas dynamics.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 50, No. 2, pp. 198–204, March–April, 2009 相似文献
6.
N. I. Sidnyaev 《Journal of Applied Mechanics and Technical Physics》2007,48(2):159-165
Results of experimental investigations of aerodynamic characteristics of models of high-velocity flying vehicles consisting
of a combination of a blunt cone, a cylinder, and a conical tail fin are presented. The model forebody is cooled by porous
blowing. The choice of such a configuration is determined by the necessity of optimizing the arrangement of high-velocity
flying vehicles on the launcher and their aerodynamic characteristics under conditions of intense surface mass transfer (decrease
in drag and heat transfer and increase in static and dynamic stability).
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 48, No. 2, pp. 19–26, March–April, 2007. 相似文献
7.
A. V. Kazakov 《Fluid Dynamics》1998,33(6):850-855
The results of a numerical investigation of the effect of thermal energy supply on a swirling viscous heat-conducting gas
flow in a subsonic cocurrent stream are presented. The initial stage of development of the swirling flow in the neighborhood
of the vortex axis with constant circulation in the outer flow region is considered for two different distributions of the
streamwise velocity vector component which simulate a swirling jet-type flow and a wake flow with a streamwise velocity deficit.
The effect of local volume energy supply in the neighborhood of the vortex axis, the circulation of the azimuthal velocity
component, and the longitudinal pressure gradient in the inviscid stream on the development of the swirling flow and the process
of breakdown of cocurrent vortex flows is investigated.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 6, pp. 47–53, November–December,
1998.
The work was carried out with financial support from the Russian Foundation for Basic Research (project No. 96-01-00586). 相似文献
8.
S. I. Arafailov 《Fluid Dynamics》1990,25(4):615-623
The problem of supersonic flow past an elongated axisymmetric body in the presence of an energy release zone between the surface of the body and the shock wave is considered. By means of such zones it is possible to modify the aerodynamic characteristics of the body and influence its flight by decreasing or increasing the drag coefficient (see, for example, [1, 2]) or by creating an additional lift force or aerodynamic moment [3]. A simple model of steady-state flow past a body with an energy source is used to determine what parameters the source should have to permit the maximization of the controlling force (in the present case the lift) for a given energy consumption per unit time.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 4, pp. 142–151, July–August, 1990.In conclusion, the author wishes to thank V. P. Stulov for his interest in the work. 相似文献
9.
V. A. Annenkov V. A. Levin E. V. Trifonov 《Journal of Applied Mechanics and Technical Physics》2006,47(2):153-156
Numerical analysis is performed of the interaction of a shock wave with a local energy source and the wake behind it. It is
shown that for specified shock-wave intensity and flow parameters there is a threshold value of the energy release starting
with which the shock wave collapses.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 47, No. 2, pp. 3–7, March–April, 2006. 相似文献
10.
S. I. Arafailov 《Fluid Dynamics》1987,22(4):645-648
The presence of an energy release zone in a supersonic stream leads to the formation of perturbations propagated from the source of energy release [1, 2]. The action of such a stream on a body past which it flows is determined by the strength of the source and the configuration and location of the energy release zone. The dependence of the aerodynamic characteristics of a blunt cone on the parameters of the source of energy release is analyzed on the basis of the results of a numerical integration of the equations of motion of the gas.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 4, pp. 178–182, July–August, 1987.The author wishes to thank V. P. Stulov for his interest in the work and useful suggestions. 相似文献
11.
The results of calculating a supersonic turbulent boundary layer on a flat plate in the presence of thermal energy supply
to the boundary layer are presented. Two methods of energy supply are considered: heating a local interval of the surface,
which is otherwise thermally insulated and using a local volume heat source. It is shown that for the same amount of heat
supplied to the gas volume heating leads, under certain conditions, to greater friction reduction than the surface heating.
Localization of the energy supply zone leads to the intensification of the viscous drag reduction effect and to a greater
decrease in the local friction coefficient, which extends a considerable distance downstream.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, pp. 48–56, January–February,
1997.
The work was carried out with financial support from the Russian Foundation for Fundamental Research (project No. 93-013-17600). 相似文献
12.
13.
The problem of determining the integral aerodynamic characteristics of aircraft as a whole in the transonic velocity range
is considered. An approximate method of their calculation is developed using the nonlinear transonic theory of small perturbations
for three-dimensional flow over a body. The method of investigation consists in separating the flow region into two subregions
(outer and inner), applying numerical methods of integrating the equations in those regions, and joining the solutions. The
Murman-Cole method of calculating the pressure drag of an isolated wing is generalized to the case of a combination of wing
and fuselage.
Central Aerohydrodynamics Institute, Zhukovskii 140160. Translated from Prikladnaya Mekhanika i Tekhnicheskaya fizika, Vol.
39, No. 4, pp. 91–101, July–August, 1998. 相似文献
14.
G. B. Filimonikhin V. V. Pirogov I. I. Filimonikhina 《International Applied Mechanics》2007,43(10):1167-1173
The paper addresses attitude stabilization of the rotational axis of an asymmetric carrying body by pendulum dampers. Steady
motions in which the kinetic energy of the system takes stationary values are identified. Whether these motions are stable
is established
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Translated from Prikladnaya Mekhanika, Vol. 43, No. 10, pp. 120–128, October 2007. 相似文献
15.
V. S. Khlebnikov 《Fluid Dynamics》1998,33(2):284-288
Transonic and supersonic flows past a pair of bodies have been experimentally investigated. The leading bodies were spheres,
cylinders, and cones, while the trailing bodies were flat-ended circular cylinders. The leading and trailing bodies were joined
by cylindrical rods of various lengths, aligned with the axis of symmetry. For these models, the pattern of flow between the
bodies and the Mach number dependence of the drag coefficientC
x were determined in the acceleration and deceleration flow regimes in a wind tunnel. The experimental results are used to
analyze the properties of the flow between the bodies and the variation of the aerodynamic coefficients of the models. The
reasons for the hysteresis in the behavior of the coefficients in the acceleration and deceleration stages are discussed.
The influence of the shape and dimensions of the leading body on the modelC
x is evaluated.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 2, pp. 158–164, March–April, 1998. 相似文献
16.
The dynamics of a rigid cylindrical body subjected to high-frequency rotational vibration about its own axis in a liquid-filled
sector of a horizontal cylindrical layer are investigated experimentally and theoretically. It is found that the vibrations
generate an average force on the body which in the case of a body denser than the fluid is directed toward the axis of rotation.
Under certain conditions this force exceeds the gravity force, causing the body to float. This effect is analyzed theoretically
in the high-frequency low-amplitude vibration approximation. It is shown that the force detected acts on the body over the
entire fluid volume.
Perm’. Paris. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 4, pp. 29–39, July–August,
1998.
The work partially supported by the Russian Foundation for Basic Research (project No. 96-01-00932) and Grant No. 920-5208/95
of the US National Aviation and Space Administration (US NASA). 相似文献
17.
Vertical motion of a rotational body in an air environment as a mechanical model of a rotochute is considered. It is assumed that, in the process of motion, the symmetry axis of the rotational body remains vertical and the rotational body itself rotates relative to this axis. The aerodynamic impact model is based on a quasistatic approach. Steady regimes of motion are identified, their stability is analyzed, and certain features of transition regimes are explored, including those related to the exchange between the energy of rotational motion and the energy of translational motion. 相似文献
18.
The present paper reports an experimental investigation on atomizing liquid flows produced by simplified cavity nozzles. The Weber number being kept low, the sprays produced by these injectors depend on the liquid flow characteristics only, and more precisely, on the non-axial kinetic energy and of the turbulent kinetic energy at the nozzle exit. The investigation reported here concentrates on the characterization of liquid flows during atomization by measuring the spatial variation of the local interface length and of the local interface fractal dimension. Both parameters were found representative of the physics of atomization process: they depend on the characteristics of the flow issuing from the nozzle and they are related to the subsequent drop size distribution. The local interface length is representative of the amount of liquid–gas interface surface area, and is a function of both the non-axial and the turbulent kinetic energies at the nozzle exit. The fractal dimension is representative of the tortuosity of the liquid–gas interface and, as expected, is mainly related to the turbulent kinetic energy at the nozzle exit. As far as the drop size distribution is concerned, it is found that the local interface length at the instant of break-up determines a representative drop diameter of some kind, whereas the fractal dimension at the same instant controls the dispersion of the distribution. 相似文献
19.
Despite their lack of appendages, flying snakes (genus Chrysopelea) exhibit aerodynamic performance that compares favorably to other animal gliders. We wished to determine which aspects of
Chrysopelea’s unique shape contributed to its aerodynamic performance by testing physical models of Chrysopelea in a wind tunnel. We varied the relative body volume, edge sharpness, and backbone protrusion of the models. Chrysopelea’s gliding performance was surprisingly robust to most shape changes; the presence of a trailing-edge lip was the most significant
factor in producing high lift forces. Lift to drag ratios of 2.7–2.9 were seen at angles of attack (α) from 10–30°. Stall
did not occur until α > 30° and was gradual, with lift falling off slowly as drag increased. Chrysopelea actively undulates in an S-shape when gliding, such that posterior portions of the snake’s body lie in the wake of the more
anterior portions. When two Chrysopelea body segment models were tested in tandem to produce a two dimensional approximation to this situation, the downstream model
exhibited an increased lift-to-drag ratio (as much as 50% increase over a solitary model) at all horizontal gaps tested (3–7
chords) when located slightly below the upstream model and at all vertical staggers tested (±2 chords) at a gap of 7 chords. 相似文献
20.
The problem of the axisymmetric potential flow past a body of revolution with a channel along the axis in the presence of
a recirculation flow zone near the body, first proposed by G. Yu. Stepanov, is solved.
Kazan’. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, pp. 14–21, January–February,
2000.
The study was carried out with the support of the Russian Foundation for Basic Research (project No. 96-01-00123). 相似文献