Begell House Inc.
TsAGI Science Journal
TSAGI
1948-2590
43
2
2012
NUMERICAL SIMULATION OF A SPANWISE JET BLOWING EFFECT ON A FLOW AROUND A WING AIRFOIL
137-145
10.1615/TsAGISciJ.2012005502
Vladimir Valeryevich
Bogatyrev
Central Aerohydrodynamic Institute, 1, Zhukovsky Str., Zhukovsky, Moscow Region, 140180 Russia
Albert Vasilievich
Petrov
Central Aerohydrodynamic Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, 140180, Moscow region
spanwise blowing
airfoil
flap
unsteady flow
An approximate method for numerical simulation of an unsteady separated flow over an arbitrary shaped airfoil with a flap and spoiler in the presence of a cross-section jet blowing over the airfoil or deflected flap is developed. The method is based on the usage of vortex-type singularities for the simulation of the ideal incompressible flow with a fixed separation point on the airfoil surface and the ejection properties of the jet by a specified intensity sink located above the airfoil surface. Examples are presented for the flow calculations and aerodynamic characteristics of the wing airfoil with the simulated blowing effect at high angles of attack and for the airfoil with the flap deflected at an angle of δf = 50°. The method applicability is shown for determining an optimal chordwise nozzle position. A comparison of the numerical results with the experimental data is presented.
ASYMMETRY AND NON-UNIQUENESS OF THE SOLUTION TO THE PROBLEM OF A SEPARATED FLOW ABOUT A SLENDER WING/LOW-ASPECT-RATIO BODY CONFIGURATION WITH SIDESLIP
147-154
10.1615/TsAGISciJ.2012005494
Aleksandr Vladimirovich
Voevodin
Central Aerohydrodynamic Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, 140180, Moscow region, Russia
asymmetry
non-uniqueness
separated flow
cone-delta wing
low aspect ratio
computations with allowance for viscosity
vortex breakdown
Earlier investigations into the problem of a separated flow about a slender wing/low-aspect-ratio body configuration with zero sideslip show that the flow becomes asymmetrical at angles of attack greater than 13 °, and a considerable side force appears. It is obvious that two mirror-symmetrical solutions with the side force having identical absolute values with opposite signs have to exist. The present paper is devoted to obtaining such solutions and to investigating the flow about the configuration with non-zero sideslip angles β. The computations show that the side force is an essentially nonlinear function of the sideslip angle at sufficiently high angles of attack. The cz (β) curves acquire the form of a loop, and the problem at | β | < 4−5° has two solutions. The derivatives of the side force coefficient cz with respect to the sideslip angle at β = 0 become negative. At angles of attack greater than 35°, the flow is accompanied by an asymmetrical breakdown of the vortex shed from one of the wing edges, which affects the aerodynamic forces acting on the configuration. Computed flow patterns in a cross section of the conical part of the model are presented to illustrate specific features of the flow.
ON AN APPROXIMATE SIMULATION METHOD OF BULK VISCOSITY AND RELAXATION PRESSURE
155-174
10.1615/TsAGISciJ.2012005505
Vladlen Sergeevich
Galkin
Central Aerohydrodynamic Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, 140180, Moscow region, Russia
balance population system
bulk viscosity
relaxation pressure
generalized Chapman-Enskog method
A general system of equations of nonequilibrium (relaxational) gas dynamics is presented for laminar flows of a polyatomic reacting gas mixture, involving the system of population balance for all exited quantum energy levels of particles. The approximate simulation method of bulk viscosity and relaxation pressure is demonstrated with the help of a series of expansion of solutions of the equations for the population balance in a small parameter for a particular important example. The resulting relations are compared with the solution of the corresponding system of kinetic equations in the frame of the generalized Chapman-Enskog method for estimation of the accuracy of the simulation method.
EFFECT OF GAS CIRCULATION IN CYLINDRICAL SOURCES ON THE THERMAL CRISIS
175-191
10.1615/TsAGISciJ.2012005495
Arkadii Nikolaevich
Kucherov
Central Aerohydrodynamic Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, 140180, Moscow region, Russia
source
vortex source
heat addition
Mach number
crisis
similarity parameters
Publications dealing with the estimation and determination of the fraction of energy absorbed by gas molecules, which is transformed to the kinetic energy of translational motion by means of measuring the pressure distributions on the side walls parallel to the flow, are briefly reviewed. The influence of circulation in the mass source (sink) on the thermal crisis is studied; new effects and possibilities of flow control are described. Basic trends of changes in the vortex source (vortex sink) parameters at a given heat addition in the layer are considered as functions of the gas type (ratio of specific heats), heat release region location and length, distribution function of the heat release intensity, gas flow circulation, and boundary conditions. The possibility of controlling the flow transition through a Mach number equal to unity is demonstrated.
AERODYNAMIC EXPERIMENTAL PLANTS FOR AIR-JET ENGINES
193-209
10.1615/TsAGISciJ.2012005496
Oleg Vasilyevich
Voloschenko
Central Aerohydrodynamic Institute (TsAGI), Zhukovsky Str. 1, Zhukovsky, Moscow Region, 140180 Russia
Sergey Anatolyevich
Zosimov
Central Aerohydrodynamic Institute (TsAGI), Zhukovsky Str. 1, Zhukovsky, Moscow Region, 140180 Russia
Aleksey Anatolyevich
Nikolaev
Central Aerohydrodynamic Institute (TsAGI), Zhukovsky Str. 1, Zhukovsky, Moscow Region, 140180 Russia
Vladimir Nikitovich
Ostras
Central Aerohydrodynamic Institute (TsAGI), Zhukovsky Str. 1, Zhukovsky, Moscow Region, 140180 Russia
Valeriy Nikolaevich
Sermanov
Central Aerohydrodynamic Institute (TsAGI), Zhukovsky Str. 1, Zhukovsky, Moscow Region, 140180 Russia
Aleksandr Fedorovich
Chevagin
Central Aerohydrodynamic Institute (TsAGI), Zhukovsky Str. 1, Zhukovsky, Moscow Region, 140180 Russia
wind tunnel
parallel-flow air-jet engine for high flight speeds
fuel combustion in the supersonic flow
simulation of the flight conditions
experimental investigations in aerodynamics
The peculiarities of simulating the flight conditions necessary to fulfill the ground tests of air-jet engines at fuel combustion, as well as the possible tests and their constraints, are considered. Ways to design the gasdynamic channels of plants with two-stage diffusers in engine testing is discussed.
THE AREA OF VERTICAL MANEUVER OF A ROPE-TOWED VEHICLE
211-225
10.1615/TsAGISciJ.2012005508
Lev Vladimirovich
Morozov
Samara State Aerospace University, Moskovskoye Shosse 34, 443086, Samara, Russia
rope system
towed vehicle
tubular rope
aerodynamic drag
vertical and horizontal motion
maneuver area
This article deals with the motion of a small-sized flying vehicle, towed with a flexible rope by a forward-flying carrier aircraft. Due to drag alteration, the flying vehicle can move horizontally and vertically when towed with a variable-mass rope. The maneuver area limits are determined for vehicles towed with tubular and solid-section ropes in the range of all altitudes and subsonic speeds of the carrier aircraft.
PARAMETRICAL INVESTIGATIONS OF THE REGULARITIES OF THE NATURAL VIBRATION MODE CHARACTERISTICS OF AIRPLANE STRUCTURES
227-245
10.1615/TsAGISciJ.2012005503
Andrey Vyacheslavovich
Gubernatenko
Central Aerohydrodynamic Institute (TsAGI), Zhukovsky Str. 1, Zhukovsky, Moscow Region, 140180 Russia
Vyacheslav Vladimirovich
Lyschinsky
Central Aerohydrodynamic Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, 140180, Moscow region, Russia
Valeriy Arkadievich
Mosunov
Central Aerohydrodynamic Institute (TsAGI), Zhukovsky str. 1, Zhukovsky, 140180, Russia
Anatoliy Alekseevich
Rybakov
Central Aerohydrodynamic Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, 140180, Moscow region, Russia
theory of similarity
mechanical systems
airframes
dynamically similar models
parametrical investigations
regularities
ground vibration tests
The natural vibration modes of mechanical systems with different numbers of degrees of freedom are considered. The common vibration features of two- and multi-degree systems are compared. The similarities and differences between the parametrical dependencies and the possibility of change in vibration phases at varying parameters is considered.
RATIONAL DESIGN OF STRUCTURES IN ACCORDANCE WITH STRENGTH CRITERIA USING COMPUTING SYSTEMS
247-256
10.1615/TsAGISciJ.2012005504
Vyacheslav Ivanovich
Grishin
Central Aerohydrodynamic Institute (TsAGI), Zhukovsky Str. 1, Zhukovsky, Moscow Region, 140180 Russia
Maksim Nikolaevich
Koledov
OAO IRKUT Corporation, Bldg. 1,13, Novoalekseevskaya St., Moscow, 129626 Russia
optimization
computing programs
finite-element method
The procedure of estimation of rational load-bearing units of aviation parts in accordance with strength criteria using the MSC Patran−Nastran and MATLAB computing systems is proposed. In the specified design domain with a uniform thickness and modulus distribution the procedure iteratively analyzes the stress condition and defines the reinforcement of the structure elements in the direction of principal loads by adding the material thickness or modulus. Examples of the solution of the applied problems are presented.