Begell House Inc.
TsAGI Science Journal
TSAGI
1948-2590
41
1
2010
TO THE READERS
1-2
10.1615/TsAGISciJ.v41.i1.10
Sergei Leonidovich
Chernyshev
Central Aerohydrodynamic Institute (TsAGI), Zhukovsky, Moscow region, Russia
We offer you two special issues of TsAGI Science Journal for 2010 (No. 1 and No. 2)
which contain papers prepared from presentations at The 2nd Open All-Russian Conference,
Computational Experiments in Aeroacoustics (24−27 September 2008). The Computational
Experiments in Aeroacoustics conferences have taken place since 2006 in the
second half of September in the Svetlogorsk, Kaliningrad, region once every 2 years,
alternating with traditional conferences on aviation acoustics carried out by TsAGI in
Zvenigorod. The Institute of Mathematical Modeling of RAS is the initiator of the Computational
Experiments in Aeroacoustics conferences, and the corresponding member of
RAS, B. N. Chetverushkin, is the convener.
AZIMUTHAL COMPONENTS OF TURBULENT JET SOUND FIELD:MEASUREMENT RESULTS AND THEIR IMPLEMENTATION FOR VALIDATION OFMODERN NOISE COMPUTATION TECHNIQUES
3-13
10.1615/TsAGISciJ.v41.i1.20
M. L.
Shur
Central Aerohydrodynamic Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, 140180,Moscow region; and Russian Scientific Center “Applied Chemistry”, St. Petersburg, Russia
Victor F.
Kopiev
Central Aerohydrodynamic Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, 140180,Moscow region, Russia
jet noise
azimuthal decomposition technique (ADT)
large eddy simulations (LES)
validation
This paper presents a brief description of an experimental technique developed at TsAGI for measurement of the amplitudes of the azimuthal components of the aerodynamic sound field, the azimuthal decomposition technique (ADT), and the results of the first attempt to validate numerical approaches to jet noise prediction based on comparison with ADT data. In this sense, ADT ensures a fundamentally new possibility since the directivity of the azimuthal noise components is a much more subtle characteristic than the total noise measured in conventional aeroacoustic experiments. A numerical system being analyzed is developed at St. Petersburg State Polytechnical University and is aimed at jet noise prediction on the basis of large eddy simulations for turbulence and of the surface integral
method of FfowcsWilliams and Hawkings for the far-field noise computation. The measurements and the computations are performed for a subsonic unheated jet with velocity V = 137 m/s. The analysis of comparison of the predictions with the experimental data evinces the usefulness of the detailed information provided by ADT not only with respect to validation, but also for enhancement of the accuracy of aeroacoustic simulations.
METHOD OF ENGINEERING CALCULATIONS OF ACOUSTIC AND THRUST CHARACTERISTICS OF NOISE-SUPPRESSING NOZZLES
15-33
10.1615/TsAGISciJ.v41.i1.30
Sergey Mikhailovich
Bosnyakov
Central Aerohydrodynamic Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, 140180, Moscow region, Russia
Vladimir Viktorovich
Vlasenko
Central Aerohydrodynamic Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, 140180, Moscow region, Russia
A. V.
Lysenkov
Central Aerohydrodynamic Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, 140180, Moscow region, Russia
Sergey Vladimirovich
Mikhaylov
Central Aerohydrodynamic Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, 140180, Moscow region, Russia
Morozov
Alexander
TsAGI
computational aeroacoustics
noise-suppressing nozzle
thrust coefficient
turbulent jet noise
method of instability waves
Kirchhoff formula
noise spectrum
The numerical methodology of approximate calculations of thrust and acoustic characteristics of nozzles
with complex geometry is described. It includes (i) calculation of the time-averaged flow field
around the nozzle based on Reynolds-averaged Navier-Stokes equations, (ii) simulation of acoustic
perturbations propagation over the time-averaged flow field in the nozzle near field, and (iii) estimation
of the far sound field and third-octave spectra of sound radiation in several directions. The results
of the time-averaged flow field and thrust coefficient calculation for the sector nozzle are presented.
Methodical calculations of the nozzle sound field are considered.
THE TECHNIQUE OF ACCURACY INCREASE WHILE SIMULATING ACOUSTIC DISTURBANCE TRANSFER ON UNSTRUCTURED GRIDS
35-45
10.1615/TsAGISciJ.v41.i1.40
I. V.
Abalakin
Central Aerohydrodynamic Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, 140180, Moscow region, Russia
H.
Uvrard
Central Aerohydrodynamic Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, 140180, Moscow region, Russia
A.
Dervieux
Central Aerohydrodynamic Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, 140180, Moscow region, Russia
T. K.
Kozubskaya
Central Aerohydrodynamic Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, 140180, Moscow region, Russia
computational aeroacoustics
higher-order vertex-centered methods
unstructured grids
This paper considers two ways of accuracy increase while simulating numerically the acoustic disturbance transfer on unstructured grids, using the vertex-centered algorithms. Numerical estimation of the accuracy of both techniques is carried out for the example of the numerical solution of the model
problem.
NUMERICAL INVESTIGATION OF THE INTERACTION OF ACOUSTIC DISTURBANCES WITH A SHOCK WAVE
47-57
10.1615/TsAGISciJ.v41.i1.50
A. Yu.
Ovsyannikov
Novosibirsk State University, 2, Pirogova str., Novosibirsk, 630090, Russia and Ecole Centrale de Lyon, 36, av. Guy-de-Collongue, 69134, Ecully Cedex, France
A. N.
Kudryavtsev
Khristianovich Institute of Theoretical and Applied Mechanics, Russian Academy of Sciences, Siberian Division 4/1, Institutskaya str., Novosibirsk, 630090, Russia
sound reflection and refraction
supersonic flows
shock waves
high order compact-difference scheme
The interaction of acoustic waves with a shock wave is simulated numerically. Both sound reflection
and refraction are investigated. Numerical simulations are performed with resolving the interior viscous
structure of shock transition. A high-order compact-difference scheme is used to solve the compressible
Navier-Stokes equations (NS). It is shown that in the limiting case when the wavelength
of incident disturbances is much greater than the shock thickness, the results of simulations within
a wide range of Mach numbers and angles of incidence of disturbances correspond very accurately
to the predictions of the classical linear inviscid theory. The results obtained enable an unambiguous
conclusion on the incorrectness of the recently proposed alternative theory of interaction of shock
waves with small disturbances to be made.
GENERALIZATION OF THE GODUNOV METHOD TO THE PROBLEMS OF COMPUTATIONAL AEROACOUSTICS
59-70
10.1615/TsAGISciJ.v41.i1.60
Igor Stanislavovich
Menshov
Keldysh Institute of Applied Mathematics of the Russian Academy of Sciences, 4, Miusskaya Square, Moscow 125047, Russia
linearized Euler equations
numerical methods
Godunov scheme
The generalization of the numerical Godunov method to aeroacoustics problems associated with the
calculation of sound waves generation and propagation in a compressible fluid is considered. Stated
in the present paper is the problem of the variation of the exact solution of the Riemann problem (the
problem about the decay of an arbitrary discontinuity in gas) at small perturbations of the initial
data.We show that this problem has a unique solution, which can be obtained in an explicit, analytic,
and rather compact form for arbitrary values of the initial data perturbations. The obtained solution
specifies the resultant acoustic flux, which arises during the interaction of the uniform fields of small
perturbations on the background of the decay of an arbitrary discontinuity. This allows us to construct
an analogue to the Godunov method for the system of linearized Euler equations describing
the evolution of the acoustic field on the background of the nonuniform main flow. The calculation
results, which show the efficiency of the proposed method, are given.
APPROACH TO THE SOLUTION OF THE INVERSE PROBLEMS OF TURBO-MACHINE ACOUSTICS
71-78
10.1615/TsAGISciJ.v41.i1.70
Sergei Vladimirovich
Rusakov
Perm State University, Bukireva St. 15, 614990, Perm, Russia
Mikhail Vladimirovich
Usanin
OJSC "Aviadvigatel", 93 Komsomolski prospect, Perm, GSP, Russia, 614990
Aleksandr Aleksandrovich
Siner
OJSC "Aviadvigatel", 93 Komsomolski prospect, Perm, GSP, Russia, 614990
Aleksey Matveevich
Sipatov
OJSC "Aviadvigatel", 93 Komsomolski prospect, Perm, GSP, Russia, 614990
mode structure
acoustic mode
linearized Euler equations
A method for analysis of sound fields generated by turbomachinery is presented. This method is
based on the presentation of pressure as a sum of simple acoustic modes. The method allows us to
determine the participation of each mode to the overall sound field by means of pressure measurement
on the stationary microphone grid. Unsteady linearized Euler equations are used to link the modal
amplitude and the pressure measured by the microphones. These Euler equations are solved by the
time-marching method. Analysis of the proposed method is carried out. Developed in this work are
the ideas of several foreign authors about the turbo-machine sound mode structure. The technique
allowing the definition of relative contributions of single modes to the total acoustic field is worked
out on the basis of these ideas. Some mathematical features of this technique are investigated in this
work.
USE OF ACOUSTIC ANALOGY WITH LARGE EDDY SIMULATION FOR TURBULENT JET NOISE MODELING
79-95
10.1615/TsAGISciJ.v41.i1.80
A. P.
Dowling
Whittle Laboratory University of Cambridge Department of Engineering, 1 JJ Thompson Avenue, Cambridge, CB3 0DY, United Kingdom
Sergey Aleksandrovich
Karabasov
University of Cambridge, The Old Schools, Trinity Lane, Cambridge CB2 1TN, United Kingdom
T. P.
Hynes
Whittle Laboratory University of Cambridge Department of Engineering, 1 JJ Thompson Avenue, Cambridge, CB3 0DY, United Kingdom
turbulent jet noise
acoustic analogy
Goldstein’s formulation
large eddy simulation
linearized Euler equations
adjoint Green function
finite-difference methods
A novel acoustic analogy approach is considered for jet noise modeling within the generalized acoustic analogy framework. The approach is based on large eddy simulation and is empirical-parameter free. Numerical predictions are provided for a subsonic isothermal axisymmetric jet case (JEAN ex-
periment).
CORONA DISCHARGE MICROJETS AS POSSIBLE ACTUATORS FOR JET NOISE CONTROL
97-107
10.1615/TsAGISciJ.v41.i1.90
N. N.
Ostrikov
Central Aerohydrodynamic Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, 140180,Moscow region, Russia
Victor F.
Kopiev
Central Aerohydrodynamic Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, 140180,Moscow region, Russia
jet noise control
vortex rings
corona discharge
plasma actuators
The objective of this study is to find instruments for active turbulent jet noise control that are based
on the resonant breakdown of large-scale power-intensive vortices. For resonant excitation of largescale
vortex rings in turbulent jets, it is for the first time suggested to use the microjets generated by
pulsating corona discharge. A system of actuators with six anode needles is proposed for resonant excitation
of Bessel oscillation modes of the ring vortex core. The presence of the effect of the destruction
of the vortex rings is demonstrated in the jet velocity range 12−30 m/s. It is shown that this effect
is sensitive to the configuration of the whole system of actuators, including the mutual position of
each pair of anode and cathode needles as well as the positioning of anode needle relative to the flow
direction. The main conclusion consists of the fact that the effect of the destruction of vortex rings
is of a resonant nature, since it is achieved only by the action of pulsating microjets, and not by the
action of steady microjets generated by dc corona discharge.
VIBROACOUSTIC PROCESSES MODELING IN THE TURBOJET ENGINE AND OTHER POWER PLANT UNITS BASED ON FREQUENCY CHARACTERISTICS INVESTIGATION OF THE “ENGINE-MOUNTING-AIRFRAME” SYSTEM
109-118
10.1615/TsAGISciJ.v41.i1.100
V. S.
Baklanov
Tupolev Design Bureau (Tupolev) 17, Tupolev Embankment, Moscow, 105005, Russia
turbo-jet engine
by-pass ratio
frequency spectrum
fan
shock waves
vibration
dynamic forces
structure noise
dynamic compliance
transfer function
Vibroacoustic processes investigations in an air-gas duct and in several units of GTE and their comparison to vibration loading of the engine body show significant interplay between these two processes. This paper presents a calculation model of a multicoupled system, namely, an "engine-mounting-airframe" system. This model is developed on the basis of experimental investigations of the frequency characteristics of dynamic compliances and vibroacoustic conductivities of the engine body and of the airframe in attachment points. This model allows us to work out a set of algorithms for estimation of acoustic processes in a gas-air duct, of vibration characterictics of the power plant
units (for example, plunger pumps), and of dynamic loading of the engine attachment points.