Caltech* experiments confirm the theoretical conceptâ of hypersonic laminar flow control black squares - solid wall open circles - porous wall arrowed circles ...
AIAA 2003-4147
Stability of Hypersonic Boundary Layer on Porous Wall with Regular Microstructure A. Fedorov and V. Kozlov Moscow Institute of Physics and Technology, Zhukovski, 140180, Russia A. Shiplyuk, A. Maslov, A. Sidorenko and E. Burov Institute of Theoretical and Applied Mechanics, Novosibirsk, 630090, Russia N. Malmuth Rockwell Scientific Company, Thousand Oaks, California 91360, USA
Speaker Could Not Present due to Visa Problems. Paper is Available. Here, a Brief Summary by the Session Chair This effort was supported by the European Office of Aerospace Research and Development under the International Science and Technology Center (ISTC) partner grant No. 1863. The authors are grateful to Dr. John Schmisseur and Dr. Steven Walker for support of this research project.
Caltech* experiments confirm the theoretical concept† of hypersonic laminar flow control Ultrasonically absorptive coating with equally-spaced cylindrical blind micro-holes was able to increase laminar run on a sharp hypersonic cone more than twice Sharp cone model with porous surface 6
5x10
Perforated sheet with blind cylindrical holes: • hole diameter 60 microns • hole depth 500 microns • spacing 100 microns
6
4x10
6
Retr
3x10
6
2x10
6
1x10
0
3
~100 holes per 1 mm2
black squares - solid wall open circles - porous wall arrowed circles - flow is totally laminar
4
5
6
7
8
9
10
11
12
H0, MJ/kg
Summary of Caltech data (H0 is total enthalpy) *Rasheed,
A., Hornung, H.G., Fedorov, A.V., and Malmuth, N.D., AIAA J., 40, No. 3, 2002. †Fedorov & Malmuth et al., AIAA J., 39, No. 4, 2001
1 mm
ITAM stability experiments on felt-metal coating agree well with LST* For Fornatural naturaldisturbances disturbances UAC stabilizes UAC stabilizesthe thesecond second mode and destabilizes fow1 mode and destabilizes fow2 frequency frequencydisturbances disturbances(first (first mode?) mode?)
2.5
A
2.0
second mode
first mode
1.5
1.0
0.5
Felt-metal Felt-metalcoating coating ofof0.75 mm 0.75 mm thickness thickness
0.0
0
100
200
300
f, kHz 700 600 500 400 300
theory, porous theory, solid exp., porous exp., solid
Theory
id sol
200
ous por
A
Amplitudes Amplitudesofof artificially artificiallyexcited excited wave wavepacket packetofof280 280 kHz agree well with kHz agree well with LST LST
100 90 80 70 60 50
Experiment
40 30
200
240
280
X, mm *Fedorov
A., Shiplyuk, A., Maslov, A., Burov, E., and Malmuth, N., AIAA Paper No. 2003-1270, 2003; JFM, Vol. 479, 2003, pp. 99-124.
320
Objectives • Perform theoretical and experimental studies of porous coating of regular microstructure • Include gas rarefaction effect in theoretical model of acoustic absorption • Conduct stability measurements of natural and artificially excited disturbances • Compare LST predictions with experiment
Porous coating is similar to UAC of Caltech experiments* 2r0
s perforated sheet
s Top view
holes
s h Side view
solid backing
Stainless Stainlesssteel steelsheet sheetperforated perforatedwith with equally equallyspaced spacedcylindrical cylindricalholes: holes: ••Diameter Diameter50 50µm µmon onface faceside side ••Spacing Spacing100 100µm µm Face side, d= 50 µm
Back side, d= 64 µm
Pores are conical, taper angle~0.9° *Rasheed,
••Depth Depth450 450µm µm ••Porosity Porosity20% 20%
A., Hornung, H.G., Fedorov, A.V., and Malmuth, N.D., AIAA J., 40, No. 3, 2002.
Sharp-cone model tested in the T-326 wind tunnel of ITAM UAC
Perforated sheet was tensed onto the model to avoid cavities Base part with the porous coating
Spectra of Natural Disturbances on Solid and Porous Sides (M=5.95, T0=390K, Tw/T0=0.80-0.84) Low-frequency fist mode
High-frequency second mode ReeX *10- 6
Re eX *10- 6
Amplitude
100
2.22 2.50 2.78 3.06 3.34 3.62 3.90 4.27 4.55 4.80 5.06
Stabilization effect
100
Amplitude
2.28 2.55 2.84 2.96 3.24 3.52 3.79 4.28 4.54 4.78 4.99
10
10
0
100
200
f, kHz
300
Solid side
400
500
0
100
200
f, kHz
300
400
Porous side
Porous Porouscoating coatingstabilizes stabilizesthe the second secondmode modeand andweakly weaklyaffects affects the thefirst firstmode mode
500
Artificially Excited Wave Packets in Boundary Layer on Porous Walls
frequency 275 kHz 50
1000 Ree X *10-6
40
30
20
10
2.22 2.77 3.35 3.91 4.47 5.05
800
Amplitude
Amplitude
ReeX *10 -6
2.22 2.77 3.35 3.91 4.47 5.05
600
400
200
0 -20
-10
0 θ, deg
10
20
Amplitude vs. circumferential angle
0 -4
0 β, rad/deg
β-spectra
Dominant Dominantcomponent componentof ofartificially artificiallyexcited excitedwave wave packet packetis istwo-dimensional two-dimensionalwave waveof ofβ=0 β=0
4
Phase Speeds and Amplitudes of Natural and Artificial Disturbances frequency 275 kHz
Solid side, artificial
100
1
0.96
A00 A/A
1 2 3
4 0.92 C x /U e
10
Porous side, natural
0.88
1 Porous side, 2 artificial 3
0.84
0.8 120
160
200
X, mm
240
280
Phase speeds of artificially excited wave packets
320
2
3
4 ReeX*10-6
5
6
Amplitude growth of artificial and natural disturbances
Natural Naturaldisturbances disturbancesof ofhigh highfrequency frequencyare arepredominantly predominantly 2-D 2-Dwaves wavesof ofthe thesecond secondmode. mode.
For Kn
