Begell House Inc.
TsAGI Science Journal
TSAGI
1948-2590
40
2
2009
NUMERICAL SIMULATION OF AERODYNAMICS OF WINGED RE-ENTRY SPACE VEHICLE
131-149
10.1615/TsAGISciJ.v40.i2.10
A. V.
Vaganov
Central Aerohydrodynamic Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, 140180, Moscow region, Russia
Sergei Mikhailovich
Drozdov
Central Aerohydrodynamic Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, 140180, Moscow region, Russia
Alexander Petrovich
Kosykh
Central Aerohydrodynamic Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, 140180, Moscow region, Russia
Garry Grantovich
Nersesov
Central Aerohydrodynamic Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, 140180, Moscow region, Russia
Iraida Fedorovna
Chelysheva
Central Aerohydrodynamic Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, 140180, Moscow region, Russia
Vladimir L'vovich
Yumashev
Central Aerohydrodynamic Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, 140180, Moscow region, Russia
aerospace vehicle
numerical simulation
aerodynamic characteristics
real air thermophysical properties
Investigated numerically are the flow pattern and the aerodynamic characteristics of a new generation of winged re-entry space vehicles (RSVs) of comparably small size. Examined is the RSV — TsAGI [1, 2] layout, which has a complicated configuration: strongly blunt fuselage, wing with variable-swept leading edge and with two tips, elevons, fuselage trim panel, and a vertical fin with a rudder and air brake installed on it. Calculations were performed for inviscid and thermally nonconductive gas within the range of Mach numbers M∞ = 1.1−16.5 and within the range of angle of attack α = 0−45°. The main aerodynamic characteristics of RSVs, i.e., their flow field topology features, are defined by means of numerical simulation, and the influence of real air thermophysical properties at hypersonic velocities was investigated by means of numerical simulation.
OPTIMIZATION OF THE WING SHAPE IN THE WING-BODY SYSTEM AT HYPERSONIC FLOW
151-165
10.1615/TsAGISciJ.v40.i2.20
Sergey Dmitrievich
Zhivotov
Moscow Institute of Physics and Technology, Department of Aeromechanics and Flying Technics, 16, Gagarin str., Zhukovsky, 140180, Moscow region, Russia
Vladimir Stepanovich
Nikolaev
Moscow Institute of Physics and Technology, Department of Aeromechanics and Flying Technics, 16, Gagarin str., Zhukovsky, 140180, Moscow region, Russia
hypersonic flows
optimization
boundary layer
The problems of drag minimum and of the lift-to-drag ratio maximum of a wing-body system at hypersonic flow are considered. The shape of the middle surface of the trapezoidal wing and the distribution of the wing thicknesses at a given volume are varied. The influence of the viscosity effects on the aerodynamic characteristics of the optimal shapes is considered.
KINEMATIC FOUNDATIONS OF THE RANQUE EFFECT MECHANISM—HEAT SEPARATION OF FLUID AND GAS FLOW IN A VORTEX TUBE
167-190
10.1615/TsAGISciJ.v40.i2.30
A. P.
Byrkin
Central Aerohydrodynamic Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, 140180, Moscow region, Russia
V. V.
Shchennikov
Central Aerohydrodynamic Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, 140180, Moscow region, Russia
Ranque effect mechanism
automodel whirled liquid and gas flow in the channel
The known effect of gas flow heat separation discovered by Ranque [1] is still not properly explained by science. The experimental fact of such separation is also known for fluid in nominal Ranque tubes [2]. Flow heat separation was numerically simulated on the example of laminar self-similar whirled flows in expanding cone-like channels, channels had an injection vector oriented along the porous wall. The mechanism of the process, which has a kinematic basis, is brought to light. The kinematic factor that is exhibited by intense flow swirl conditions stipulates higher inner supply of viscous dissipation heat of fluid kinetic energy compared to its absence (by means of an increased radial speed gradient near the wall in its essence). The implemented mathematical model allowed reconstructing qualitatively the non-monotonic character of excess temperature t − tw alteration in the cross section of the channel with cooled walls and heat outflow of the channel, and also its negative values near the real Ranque tube axis [2]. The realized t − tw values are conditioned by the recurrent character of transition lines (via convection and thermal conductivity) of heat in the meridional section of the cone channel, those lines coincide at a specific point r = 0 from where they start. The results of the self-similar heat task solution also prove the non-monotonic profile of excess temperature and recurrence of transition lines in the case of flat cone-type fluid flow (Hamel flow in flat extending channels). The specific case of stagnation temperature stratification along the channel section in a cone-like whirled flow of viscous gas is discussed.
FINITE SYMMETRIC DISTURBANCES PROPAGATION IN A VORTEX CORD
191-205
10.1615/TsAGISciJ.v40.i2.40
Viktor Fedorovich
Molchanov
Central Aerohydrodynamic Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, 140180, Moscow region, Russia
vortex cord
disturbance propagation velocity
characteristics
The process of disturbances propagation along a vortex cord is considered under the assumption of inviscid fluid. It is shown that the cord tends to have a stepped form. The velocity of propagation for this form is calculated.
PARAMETRIC INVESTIGATIONS OF THE EFFECT OF ICING ON THE AERODYNAMIC CHARACTERISTICS OF A WING AIRFOIL
207-216
10.1615/TsAGISciJ.v40.i2.50
Olga Viktorovna
Pavlenko
Central Aerohydrodynamic Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, 140180, Moscow region, Russia
icing
wing
airfoil
CFD methods
parametric investigations
Presented in this article are the results of computational investigations of the influence of shape and thickness of ice at the leading edge of a straight wing airfoil on the flow of viscous uncompressible liquid over the wing. The influence of airfoil shape on the aerodynamic characteristics in the presence of ice growth at the leading edge is considered. The computation is fulfilled using the solution program of Navier-Stokes equations averaged by Reynolds numbers.
EXPERIMENTAL INVESTIGATION OF AERODYNAMIC LOADS IN THE TIP SECTIONS OF A RIGID BLADE OF AN INCLINED MODEL ROTOR
217-239
10.1615/TsAGISciJ.v40.i2.60
Valentina Michailovna
Scheglova
Central Aerohydrodynamic Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, 140180, Moscow region, Russia
rotor
pressure difference
slip angle
This work investigates the character and the degree of influence of a slip in the tip sections of the blade on the basis of multiple pressure measuring points. The number of drain holes in each section increases along with the increase of the number of sections where the loads are measured. Measurement of the dynamic pressure in the tip part of the blade is accomplished. The results of the pressure measurements in the tip sections at relative radii varying from 0.8 to 0.99 are given. Special attention is paid to the pressure distribution in the area immediately adjacent to the blade tip and directly at the blade tip. The flow maps of the blade tips are considered in order to accumulate experimental information. The results are presented in terms of the figures of pressure change along the radius and the chord, and information about the loads acting on the blade tip of a given configuration is given. This information can be used for design and for the calculations of loads on the blades.
DEVELOPMENT OF A MEASURING TECHNIQUE FOR THE LOW-WAVENUMBER COMPONENTS OF THE WAVENUMBER-FREQUENCY SPECTRUM OF TURBULENT WALL PRESSURE FLUCTUATIONS
241-253
10.1615/TsAGISciJ.v40.i2.70
A. N.
Kotov
Central Aerohydrodynamic Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, 140180, Moscow region, Russia
wavenumber-frequency spectrum
turbulent fluctuations
structural acoustics
The main sources of errors impeding measurement of the wavenumber-frequency spectrum of wall pressure fluctuations of turbulent boundary layers in low-wavenumber regions are analyzed. Such measurements are necessary for the calculation of fuselage skin vibrations related to its inertial excitation, and for the evaluation of noise levels in the cabin caused by these vibrations. The evaluations and the dependencies of flow parameters and the measuring system are obtained for each source of error. Based on models of the wavenumber-frequency spectrum, the author validates the applicability range of different antennas and develops an optimization method of arranging the pressure sensors which enables accurate measurements using the minimum number of transducers both for one- and two-dimensional cases.
INVESTIGATION OF THE FLOW PATTERN NEAR THE PROPELLER IN THE SHAPED RING AND WITHOUT IT AT THRUST REVERSAL
255-263
10.1615/TsAGISciJ.v40.i2.80
S. P.
Ostroukhov
Central Aerohydrodynamic Institute (TsAGI), 1, Zhukovsky str., Zhukovsky, 140180, Moscow region
propeller
shaped ring
thrust reversal
wool-tuft technique
flow pattern
Presented in this work are the results of tuft tests of the flow pattern near the propeller, operating in the shaped ring and without it, under the regime of thrust reversal in the T-104 wind tunnel with the use of a VP-107 propeller test rig. A comparison of the flow field schemes with the results of balance measurements of aerodynamic forces on the propeller and on the shaped ring is given.
THE PRINCIPAL REGULARITIES IN ELASTIC SYSTEM VIBRATIONS AT NONUNIFORM AEROACOUSTIC EXCITATION
265-278
10.1615/TsAGISciJ.v40.i2.90
Boris Maksimovich
Efimtsov
Central Aerohydrodynamic Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, 140180 Moscow region
Aleksander Yakovlevich
Zverev
Central Aerohydrodynamic Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, 140180 Moscow region
acoustics
acoustic power
turbulent pressure fluctuations
nonuniform field
elastic system
The key physical phenomena and principles defining thin-walled elastic system vibrations at nonuniform random dynamic excitation are studied. The relations between spatial nonuniformity scales, correlation scales, and phase velocity of the exciting field spectral components, wavelengths in elastic systems, and the expansion velocity of the waves in which these physical phenomena are revealed are defined. We also discuss the nature of the revealed effects of the vibration amplification. The analytical expressions are obtained for estimation of the spectral density of the elastic system vibration.