1 intelligent sensing of materials lab., department of nanomechanics effect of dissolve gas on...
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1Intelligent Sensing of Materials Lab., Department of Nanomechanics
Effect of Dissolve Gas on Luminescent Spots Induced by a Cavitating Jet
Hitoshi SOYAMA Department of Nanomechanics
Tohoku University
Flow
8th International Symposium on CavitationAugust 14 – 16, 2012, Singapore
Flow
2Intelligent Sensing of Materials Lab., Department of Nanomechanics
Erosion Surface Modification
Cavitation PeeningCP
Shot Peening
Impact at Cavitation Bubble CollapseImpact at Cavitation Bubble Collapse
Cavitation Peening
H.Soyama and Y.Sekine, International Journal of Sustainable Engineering, Vol. 3, No. 1 (2010), pp. 25-32.
H.Soyama et al., Surface & Coatings Technology, Vol. 205 (2011), pp. 3167-3174.
-600
-400
-200
0
200
0 100 200 300 400
Res
idua
l str
ess
R
MP
a
Distance from surface z m
Not-peened tp = 0.25 s/mm
0.5
1
2 5
10
20
Introduction of compressive residual stress
3Intelligent Sensing of Materials Lab., Department of Nanomechanics
Surface of solid Micro jet
NucleiCavitation bubble
Rebound
Shock wave
In water
Plastic deformationHigh speed /Low pressure Decrease of speed
L.A.Crum, J. Pys, C8-285 (1979).
100 374
1
218
Pre
ssu
re
p t
at
m
Temperature tw ℃
BoilingLiquid
Solid
Gas
Cavitatio
n
Hot SpotAdiabatic compression
Establishment of chemical reactor using a cavitating jet
ImpactCavitation peening
Schematic of cavitation bubblesSchematic of cavitation bubbles
4Intelligent Sensing of Materials Lab., Department of Nanomechanics
Hydrodynamic cavitation andUltrasonic cavitation (Sonochemistry)
11 1010 101033101022 1010440.10.1
101022
101033
101044
101055
101066
101077
1010
11
0.10.1
Non-dimensional electric power to generate cavitation Non-dimensional electric power to generate cavitation
No
n-d
ime
ns
ion
al c
av
itat
ion
imp
ac
t en
erg
yN
on
-dim
en
sio
nal
ca
vit
atio
n im
pa
ct
ene
rgy
Material testing
Impa
ct e
nerg
y =
×F
orce
Impa
ct e
nerg
y =
×F
orce
22 ×O
ccur
renc
e fr
eque
ncy
×O
ccur
renc
e fr
eque
ncy
×100×100
Ultrasonic cleaning
UltrasonicUltrasoniccavitationcavitation
Limit of aggressivity of ultrasonic
Chemical reactorChemical reactorusing cavitationusing cavitation
Original technologyOriginal technologyUS patent No. 6,855,208 B1Japan patent No. 4240972
FlowFlow
FlowFlow
Venturi tubeVenturi tube
Hydrodynamic cavitationHydrodynamic cavitationCavitating jetCavitating jet
ASTM G32
ASTM G134ILS 2010-2013
Material testing
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Severe erosive vortex cavitationRing vortex cavitation
Cloud cavitation
Vortex cavitation in shear layer
Impinging surface
Nozzle
High-speed water jet
Schematic diagram of cavitating jet Schematic diagram of cavitating jet
High speed photographHigh speed photographof cavitating jet of cavitating jet taken by Soyamataken by Soyama
WATER
Cavitating JetCavitating Jet H.Soyama , J. Soc. Mater. Sci., Japan , 47 (1998), pp. 381-387.
6Intelligent Sensing of Materials Lab., Department of Nanomechanics
Residual bubbles
Erosion
specimen Cavitation cloud
Nozzle
outlet
View of the cavitation cloud and residual bubbles
0
0.01
0.02
0.03
0.04
8 8.5 9 9.5 10
Retention time t min
Inte
nsit
y V
mV
Room air
CO2
Residual cavitation bubbles
Magnified view of methane CH4 peak
p1= 200 MPa p2 = 0.2 MPa d = 0.35mm
Reduction of carbon dioxideReduction of carbon dioxide H.Soyama and T.Muraoka, Proc.20th Inter. Conf. Water Jetting, (2010), 259-267
7Intelligent Sensing of Materials Lab., Department of Nanomechanics
H2O → H ・ + OH ・
H ・ + OH ・ → H2O
2 H ・ → H2
2 OH ・ → H2O2
2 OH ・ → O ・ + H2O
2 O ・ → O2
½ O ・ + 2 H ・ → H2O
O ・ + H2O → H2O2
0
0.01
0.02
0.03
0.04
8 8.5 9 9.5 10
Retention time t min
Inte
nsity
Vm
V
Room air
CO2
Residual cavitation bubbles
0
0.01
0.02
0.03
0.04
8 8.5 9 9.5 10
Retention time t min
Inte
nsity
Vm
V
Room air
CO2
Residual cavitation bubbles
0
0.1
0.2
0.3
0.4
1 1.5 2 2.5 3
Retention time t min
Inte
nsity
Vm
V
Room air
CO2
Residual cavitation bubbles
0
0.1
0.2
0.3
0.4
1 1.5 2 2.5 3
Retention time t min
Inte
nsity
Vm
V
Room air
CO2
Residual cavitation bubbles
CH4
H2
CO2
CO2+4H2→CH4+2H2O
Reduction of carbon dioxideReduction of carbon dioxide
CH4 peak
H2 peak
Effect of Dissolve Gas on Luminescent Spots Induced by a Cavitating Jet
Purpose
Purpose
8Intelligent Sensing of Materials Lab., Department of Nanomechanics
Pressurized water
Aspect of cavitating jet
Luminescent spots observed by EM-CCD camera
H. Soyama, Luminescent Spots Induced by a Cavitating Jet, Proc. ASME-JSME-KSME Joint Fluids Eng. Conf., (2011), AJK2011-33018.
Cavitation clouds observed by CCD camera with flash lamp
Luminescent Spots Induced by Cavitating JetLuminescent Spots Induced by Cavitating Jet
9Intelligent Sensing of Materials Lab., Department of Nanomechanics
Experimental Apparatus and Procedures Experimental Apparatus and Procedures
Acoustic noise : Hydrophone (20 kHz ~ 1 00 kHz)
High speed video camera
Electron Multiplication Cooled Charged-Coupled Device camera (EM-CCD camera)
Luminescence Analyzer (Photomultiplier Tube) 50 - 108 photons/cm2/s (1 count = 50 photons)
Figure 1: Test loop of cavitating jet
Nozzle
Flow
Flow
Target
ChamberNozzleholder
Specimen holder
Figure 2: Test chamber of cavitating jet apparatus
10Intelligent Sensing of Materials Lab., Department of Nanomechanics
= 0.005
(a) Overall view (b) Magnified view
0 40 mm
= 0.014
= 0.020
= 0.005
(a) Overall view (b) Magnified view
0 40 mm
= 0.014
= 0.020
Flow
Luminescent Spots Induced by Cavitating JetLuminescent Spots Induced by Cavitating Jet
Figure 4: Luminescent spots of cavitating jet
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(a) Original images (b) Bth8 = 10 (c) Bth8 = 100 (d) Bth8 = 200Figure 5: Luminescent spot induced by cavitating jet as a function of cavitation number and threshold level (p1 = 30 MPa, Oxygen)
1.E-02
1.E-01
1.E+00
1.E+01
1.E+02
1.E+03
0 0.005 0.01 0.015 0.02 0.025
Cavitation number σ
Bth8 = 10
101
10-1
10-2
100
Area larger than threshold level Ath mm2/s
103
102
50
100
150 200
Figure 6: Effect of threshold level on area ofluminescence spot (p1 = 30 MPa, Oxygen)
1.E-02
1.E-01
1.E+00
1.E+01
1.E+02
1.E+03
0 50 100 150 200 250
Threshold level Bth8
Figure 7: Effect of cavitation number ondistribution of area of luminescence spot (p1 = 30 MPa, Oxygen)
0.016101
Area larger than threshold level Ath mm2/s
102
100
103
= 0.012
0.02
0.008
10-1
10-2
0.005
12Intelligent Sensing of Materials Lab., Department of Nanomechanics
1.E-01
1.E+00
1.E+01
1.E+02
1.E+03
0 50 100 150 200 250
Ar
101
10-1
10-2
Area larger than threshold level Ath mm2/s
102
100
O2
Air
N2
Threshold level Bth8
Figure 8: Effect of dissolved gas ondistribution of area of luminescence spot (p1 = 30 MPa, = 0.016)
Figure 9: Effect of dissolved gason area of luminescence spot (p1 = 30 MPa, Bth8 = 150)
1.E-02
1.E-01
1.E+00
1.E+01
0 0.005 0.01 0.015 0.02 0.025
Cavitation number σ
AirO2
N2
101
10-1
10-2
Area larger than threshold level Ath mm2/s
100 Ar
13Intelligent Sensing of Materials Lab., Department of Nanomechanics
0
2
4
6
8
10
0 0.005 0.01 0.015 0.02 0.025Intensity of luminescence CL count/s
Cavitation number σ
×105
Ar
O2Air
N2
Figure 10: Effect of dissolved gas on intensity of luminescence (p1 = 30 MPa)
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Figure 11: Effect of dissolved gas on spectrum of luminescence (p1 = 30 MPa)
0
5
10
15
20
25
300 400 500 600 700Wave length λ nm
Intensity of luminescence CL counts
×103
Ar
O2
Air
N2
16Intelligent Sensing of Materials Lab., Department of Nanomechanics
1.00E+01
1.00E+02
1.00E+03
1.00E+04
1.00E+05
1.00E+06
1.00E+07
0 5 10 15 20101
102
104
Threshold level Pth Pa
103
= 0.016
0.007
105
107
106
Acoustic energy EA Pa2/s
0.01
0.022
0.019 0.013
Figure 12 : Pulse height distribution of acoustic energy (p1 = 30 MPa, Air)
17Intelligent Sensing of Materials Lab., Department of Nanomechanics
1.00E+01
1.00E+02
1.00E+03
1.00E+04
1.00E+05
1.00E+06
1.00E+07
0 0.005 0.01 0.015 0.02 0.025101
102
104
Cavitation number
103
105
107
106
Acoustic energy EA Pa2/s
Figure 13 : Acoustic energy changing with cavitation number (p1 = 30 MPa, Air)
pth = 1 Pa
3
6
9
12
0
3
6
9
0 0.5 1 1.5 2 2.5
Acoustic energy EA Pa2/s
Area larger than threshold level Ath mm2/s
Figure 14 : Correlation between acoustic energy and area of luminescent spot (p1 = 30 MPa, Air)
Approximate line
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ConclusionsConclusions
The luminescent spots were observed in the cavitating jet by EM-CCD camera.
The intensity of the luminescence spots was changing with cavitation number, and it had a maximum at certain cavitation number. The optimum cavitation number was the same as that of acoustic energy.
The intensity was changing with the dissolved gas of the water.
21Intelligent Sensing of Materials Lab., Department of Nanomechanics
Energy of individual impactEnergy of individual impact EEii
EEii = = I Ii i τ τi i AAi i IIii : : Acoustic energyAcoustic energy
ττii : : Impact durationImpact duration
A A i i : : Affective area of each Affective area of each
impactimpactAcoustic energyAcoustic energy IIii
IIii = = P Pii 2 2 / 2 / 2 ρ ρ C C PPi i : : Amplitude of pulseAmplitude of pulse
ρρ : : DensityDensityC C : : Acoustic speedAcoustic speed
Individual impact forceIndividual impact force FFii
FFii = = P Pii A Ai i
UnknownUnknown ::PPii ,, ττii
[Assumption[Assumption ]] PPii ∝∝ FFii
ττii = = constantconstant
EEii== F Fii P Pii ττii / 2 / 2 ρ ρ CC
ΣΣEEii ∝∝ ΣΣFFii 2 2ΣΣEEii ∝∝ ΣΣFFii
2 2
Measured by Measured by PVDF sensorPVDF sensor
H.Soyama et al., H.Soyama et al., J. Fluids EngJ. Fluids Eng., ., Trans. ASMETrans. ASME, , 120 (1998), pp. 120 (1998), pp. 712-718.712-718.
H.Soyama and H.Kumano, H.Soyama and H.Kumano, J. J. Testing and Testing and EvaluationEvaluation, , 30 (2002), pp. 30 (2002), pp. 421-431.421-431.