, 32, 1 (2008) 25 30

J. Inst. Electrostat. Jpn.

⺰ᢥㅦᐲᄌൻࠍ઻߁ᴤߩᵹࠇߦ↢ߓࠆᵹേᏪ㔚⃻⽎ߩ᷹ቯ㜞ᯅ ᥓ*,1, ␸ ቞ᣂ*,**㧘㣐የ⺈৻*, ↰㉿෹Ꮧ*
㧔2007 ᐕ 10 ᦬ 15 ᣣฃઃ㧘2008 ᐕ 2 ᦬ 1 ᣣฃℂ㧕Experimental Study of Electrification in Oil Flow through MetalChannels with Its Velocity Changing with Time
Satoshi TAKAHASHI*,1, Shouxin ZHU*,**, Seiichi WASHIO* and Yuki TAZATO*(Received October 15, 2007, Accepted February 1, 2008 )The present paper deals with a basic study of electrification phenomena between a mineral oil and a metal channel
when the oil flows through with a periodical and transient change. When the oil being kept still in a reservoir was
suddenly let flow, the current taken out from the metal rose to a peak value at the beginning of flow, then exponentially decreased until it leveled off with time, approaching a constant value. The smaller the time derivative of theflow rate was, the smaller the peak value of the current became. When the flow pulsated, the generated current varied
periodically with the same frequency as the flow pulsation and had a phase lag against the flow. Although this phaselag increased with the frequency, the time lag obtained by dividing the phase lag by the frequency turned out to be almost constant.

1.

⵾ᯏེߦ߅޿ߡ߽ᵹേᏪ㔚ߩ⊒↢߇໧㗴ߣߥࠆߎߣ߇ႎ๔ߪߓ߼ߦᵹേᏪ㔚ߪ㧘࿕૕ߣᶧ૕ߩ⋧ኻㆇേߦࠃߞߡਔ⠪߇ㅒᭂᕈߐࠇߡ޿ࠆ(3)ߎߣ߆ࠄ⠨߃ࠆߣ㧘࿕ᶧߩ⚵ߺวࠊߖ߿ᵹㅦߛߦᏪ㔚ߔࠆ⃻⽎ߢ޽ࠅ㧘࿕ᶧ⇇㕙ߩ㔚᳇⊛ਛ๺߇⎕ࠄࠇߡ㔚ߌߢߥߊ㧘ᵹࠇߩ᭴ㅧ߇ᵹേᏪ㔚ߦᄢ߈ߊᓇ㗀ߒߡ޿ࠆߩߢ

⩄߇ಽ㔌ߒߡᏪ㔚ߒ㧘ߘߩᓟ㔚⩄߇ౣಽ㈩ߐࠇ৻ㇱߪ✭๺ߔߪߥ޿߆ߣផ᷹ߐࠇࠆ㧚ᚒ‫ߪޘ‬⒳‫ߩޘ‬ᒻ⁁ߩ㊄ዻ⵾ᵹ〝ߦ⊒(1)ࠆࡊࡠ࠮ࠬߣߒߡℂ⸃ߐࠇࠆ 㧚․ߦᴤߥߤߩ⛘✼ᕈᵹ૕ߢ↢ߒߚ㔚⩄ࠍ᷹ቯߒߡ߈ߚ⚿ᨐ㧘ᵹㅦߩᕆỗߥᄌൻߦࠃߞߡߪ⊒↢ߒߚ㔚⩄߇ౝㇱߦ⫾Ⓧߒ߿ߔ޿ߚ߼㧘㔚૏߇਄᣹ߒߡᄙߊߩ㔚ᵹ߇⊒↢ߔࠆߎߣ߇ࠊ߆ߞߚ(4)㧚ߎࠇߪ㧘⇇㕙ߩ㔚⛘✼⎕უߦࠃࠆ᡼㔚ࠍᒁ߈⿠ߎߒ㧘੐᡿ߩේ࿃ߣ߽ߥࠆߎߣ᳇⊛ࡃ࡜ࡦࠬ߇ᵹㅦߩᄌൻߦࠃߞߡ፣ࠇ㧘ᣂߚߥဋⴧࠍ଻ߟ

(2)߇ႎ๔ߐࠇߡ޿ࠆ 㧚ᵹേᏪ㔚ߦࠃࠆ੐᡿ࠍ㒐ᱛߔࠆߚ߼ߦߦߪᤨ㑆ࠍⷐߔࠆߚ߼ߛߣ⠨߃ࠄࠇࠆ㧚ᵹ૕ᯏ᪾ߢߪ㧘⿠േߪ㧘㔚⩄ߩ⊒↢ࠍ㒐ߋߣߣ߽ߦ㧘㔚⩄ࠍㅦ߿߆ߦขࠅ㒰ߊߎ஗ᱛ߿ࡐࡦࡊߩ⣂േߥߤߦࠃࠅ㧘ᵹࠇߩ⁁ᘒߪᏱߦᄌൻߒߡߣ߇㊀ⷐߢ޽ࠆ㧚޿ࠆߣ⠨߃ࠄࠇࠆ㧚ߒߚ߇ߞߡ㧘ታᯏߦ߅ߌࠆᏪ㔚⃻⽎ࠍ⺞ዉ૕ߢ޽ࠆ㊄ዻ⵾ᵹ〝ߪ㧘ㆡಾߦࠣ࡜ࡦ࠼ߦធ࿾ߒ㧘චಽߥ✭๺ᤨ㑆ࠍ⸳ߌࠆߎߣߦࠃߞߡ㧘㔚⩄ߩ⫾Ⓧࠍ㒐ߋߎߣ߇ߢ߈ࠆ㧚ߒ߆ߒታ㓙ߦ㧘ࡈࠖ࡞࠲߿ࠝ࡝ࡈࠖࠬㇱߥߤߩ㊄ዻߴࠆ਄ߢߪ㧘ᵹㅦߩᄌൻߦࠃࠆᏪ㔚㊂ߩᄌൻߩᓇ㗀ࠍ⹦ߒߊ⺞ߴߡ߅ߊߎߣ߇㊀ⷐߣߥߞߡߊࠆ㧚ᧄ⎇ⓥߪᵹㅦߩᄌൻߦࠃߞߡ↢ߓࠆᏪ㔚㊂ࠍ᷹ቯߒ㧘ᵹㅦᄌൻ߇Ꮺ㔚㊂ߦਈ߃ࠆᓇ㗀ࠍ᣿ࠄ߆ߦߔࠆߎߣࠍ⋡⊛ߣߒࠠ࡯ࡢ࡯࠼㧦ᵹേᏪ㔚㧘ㅦᐲᄌൻ㧘㊄ዻ⵾ᵹ〝㧘⣂േ㧘✭๺* ጟጊᄢቇᄢቇ㒮⥄ὼ⑼ቇ⎇ⓥ⑼(700-8530 ጟጊᏒᵤፉਛ 3-1-1)
The Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Okayama, 700-8530,
Japan㧚
** ᄢㅪᎿᬺᄢቇᯏ᪾ቇ㒮 (116034 ㆯካ⋭ᄢㅪᏒ↞੗ሶ඙シᎿ⧞ 1 ภ)Dailian Polytechnic University, #1 Qinggongyuan Dalian
Liaoning, 116034, China
1
tsatoshi@mech.okayama-u.ac.jpߡ߅ࠅ㧘ታ㛎ߦࠃߞߡ⏕߆߼ߚ⚿ᨐߦߟ޿ߡႎ๔ߔࠆ㧚2.
2.1ᵹㅦ߇ㆊᷰ⊛ߦᄌൻߔࠆߣ߈ߩᵹേᏪ㔚ታ㛎ⵝ⟎࡮ታ㛎ᣇᴺታ㛎ߦ૶↪ߒߚⵝ⟎ߩ᭎ⷐࠍ࿑㧝ߦ␜ߔ㧚ࠣ࡜ࡦ࠼ߦធ࿾ߒߚࠬ࠹ࡦ࡟ࠬ⵾ߩ਄ㇱ࠲ࡦࠢ A (ౝᓘ 210mm㧘㜞ߐ 600mm)
ߦ⹜ᢱᶧ૕ࠍ౉ࠇߡ㔚⩄ࠍචಽ㒰෰ߔࠆߣߣ߽ߦ㧘ౝㇱߦขࠅߟߌߚ㌃ࡄࠗࡊߦᕡ᷷ⵝ⟎߆ࠄߩ᳓ࠍᓴⅣߐߖߡ᷷ᐲࠍ

26

1ua m/s

32

2008

0.50.4
0.3
0.2
0.1
0-0.1

I nA

02

a=0.030 m/s2
a=0.066 m/s
2
a=0.11 m/s-2-4

a=0.23 m/s22
a=0.52 m/s-605mesh
VG46
1015t s࿑ 3 ㅦᐲᄌൻߦ઻߁⊒↢㔚ᵹߩᄌൻFig.3 Profiles of generated current for gradual increaseof oil velocity through mesh.

࿑㧝 ᵹേᏪ㔚ታ㛎ⵝ⟎

Fig.1 Experimental apparatus for flow electrification
measurement.

࠹ࡦ࡟ࠬ⵾(SUS304)ߩ✂(㊎㊄ᓘ 0.11mm㧘㊎㊄㑆〒㔌 0.46mm㧘㐿ญ₸ 0.49)ࠍᵹࠇߦ⋥੤ߔࠆࠃ߁ߦ㧘ࠕࠢ࡝࡞᮸⢽(૕Ⓧ

I nAu a m /sᛶ᛫₸ 51014ǡm)ߦࠃߞߡ⛘✼଻ᜬߔࠆ㧚✂ࠍ᷹ቯㇱ౉ญ

0.5
0.4
0.3
0.2
0.1
0-0.1

ࠇࠆߎߣߦࠃߞߡ↢ߓࠆ㔚࿶ᄌൻࠍ㧘OP ࠕࡦࡊ(LF356㧘౉0ജࠗࡦࡇ࡯࠳ࡦࠬ 1012ǡ)ߩ㕖෻ォჇ᏷࿁〝ࠍ↪޿ߡ⚂ 100 ୚ߩᦨ߽਄ᵹ஥ߦขࠅઃߌࠆߎߣߦࠃߞߡ㧘᷹ቯㇱߦᵹ౉ߔࠆ
ᴤߣࠕࠢ࡝࡞᮸⢽ߣߩធ⸅㕙Ⓧ߇ዊߐߊߥࠆࠃ߁ߦߒߡ߅
ࠅ㧘ᴤߣࠕࠢ࡝࡞ო㕙ߩធ⸅ߪ᷹ቯ⚿ᨐߦ޽߹ࠅᓇ㗀ߒߥ޿ߎߣࠍ੍߼⏕⹺ߒߡ޿ࠆ㧚⊒↢ߒߚ㔚⩄߇ 10Mǡߩᛶ᛫ࠍᵹ

ߦჇ᏷ߒ㧘1ms ߏߣߦ AD ᄌ឵ེࠍ↪޿ߡ᷹ቯߒߚ⚿ᨐ߆ࠄ-2㔚ᵹߩᤨ㑆ᄌൻࠍ᳞߼ࠆ㧚㔚ᵹߩ᷹ቯಽ⸃⢻ߪ⚂ 3pA㧘Ⴧ᏷-4࿁〝ߩࠞ࠶࠻ࠝࡈ๟ᵄᢙߪ 1.5kHz ߢ޽ࠆ㧚หᤨߦ㧘ਅㇱ࠲ࡦmech (SUS304)
VG46
ǰ=25͠

-6
05t10

ࠢߦ⸳⟎ߒߚ⿥㖸ᵄᶧ㕙࠮ࡦࠨ(૏⟎ಽ⸃⢻ 0.172mm)㧘߹ߚ15s

࿑ 2 ㆊᷰ⊛ߥᵹㅦᄌൻߦࠃߞߡ⊒↢ߒߚ㔚ᵹߩ᷹ቯ⚿ᨐߪ࡟࡯ࠩᄌ૏⸘(➅ࠅ㄰ߒ♖ᐲ 2Ǵm)ߢᴤ㕙ᄌ૏ࠍᬌ಴ߒ㧘ᵹ㊂ࠍ᳞߼ࠆ㧚ታ㛎ߦߪᴤ࿶▤〝ߢ૶↪ߒߚ㋶‛ᴤ(VG46 ࡑࠪࡦᴤ)ࠍ↪޿ߡ߅ࠅ㧘૕Ⓧᛶ᛫₸ U v ߪ 25͠ߢ⚂ 1.21010ǡmߢ޽ߞߚ㧚Fig.2 Typical data obtained by test rig using mesh in an

2.2abrupt go-and-stop flow.

ᑯࠍ⍴ᤨ㑆ߢ㐿ߌᵹㅦࠍㆊᷰ⊛ߦᄌൻߐߖߚߣ߈ߩ᷹ቯ᷹ቯ⚿ᨐ⚿ᨐߩ৻଀ࠍ࿑ 2 ߦ␜ߔ㧚਄࿑ߪᴤ㕙ᄌൻ߆ࠄ᳞߼ߚ㐿ญㇱࠍㅢㆊߔࠆᴤߩᐔဋᵹㅦࠍ㧘ਅ࿑ߪ᷹ቯߒߚ㔚ᵹ୯ߩᄌൻࠍ㧘⺞ᢛߔࠆ㧚ታ㛎ߪ㧘ᑯ a ࠍ㐿㐽ߒ㧘චಽ㒰㔚ߒߚᶧ૕ࠍ࿶❗

ߘࠇߙࠇᵹࠇᆎ߼߆ࠄߩᤨ㑆ߦኻߒߡឬ޿ߡ޿ࠆ㧚ᵹࠇߪߓⓨ᳇ߢ᛼ߒ಴ߒߡ᷹ቯㇱ(ౝᓘ 50mm)ࠍㅢㆊߐߖ㧘ਅㇱ࠲ࡦ߼ߦᄢ߈ߥ⽶ߩ㔚ᵹ߇⊒↢ߒ㧘⚂ 5 ⑽ᓟߦᵹㅦߦᲧ଀ߒߚቯ

ࠢ B (ౝᓘ 260mm㧘㜞ߐ 450mm)ߦ⫾߃ࠆ㧚᷹ቯㇱߦߪ㧘ࠬᏱ⁁ᘒߩ୯߳ߣ⪭ߜ⌕޿ߡ޿ࠆ㧚᷹ቯ㔚ᵹ߇⽶ߢ޽ࠆߎߣ߆

274
Ǿ=Ǹ/2-2

3-4

2

00.1

0.2

0.3 0.4
2
am/s

0.5

Ǿ=Ǹ

Ǿ=Ǹ
Ǿ=02
Ǿ=01
Ǿ=3Ǹ/2Ǿ=3Ǹ/2000.6

f=500Hz3 Ǿ=Ǹ/2

1-64

f=50Hzu/u0mesh (SUS304)
ǰ=25͠

u/u0

I p nA00.5
r/r0

࿑ 4 ᐔဋടㅦᐲߣᦨᄢ㔚ᵹߣߩ㑐ଥ

100(a) f=50Hz

Fig.4 Correlation between the peak value of current and accel-0.5
r/r01(b) f=500Hz࿑ 5 ⣂േᤨߩᵹㅦಽᏓߩᄌൻ

eration of oil flow.

Fig.5 Velocity distribution in pulsating flow.

ࠄ㧘ࠬ࠹ࡦ࡟ࠬ✂߇⽶ߦ㧘ᴤ߇ᱜߦᏪ㔚ߒߡ޿ࠆߎߣ߇ࠊ߆

୯ࠍᢥ₂(5)ߩᑼߦઍ౉ߒߡ⸘▚ߒߚ▤〝ඨᓘᣇะߩᵹㅦಽ

ࠆ㧚Ꮣߪ㧘࿑ 5 ߩࠃ߁ߦߥࠆ㧚࿑(a)ߪ⣂േ๟ᵄᢙ f ߇ 50Hz ߩ㧘ᰴߦ㧘࿑ 1 ߩᑯ a ߩ㐿㐽ㅦᐲࠍᠲ૞ߒ㧘ᵹㅦࠍᄌ߃ߥ߇ࠄ

࿑(b)ߪ 500Hz ߩㅦᐲಽᏓߩ⚿ᨐߢ޽ࠆ㧚ᮮゲߪ▤〝ඨᓘ r0 ߢ᷹ቯߒߚ⚿ᨐ߇࿑ 3 ߢ޽ࠆ㧚ߤߩ᷹ቯߦ߅޿ߡ߽㧘ቯᏱ⁁ᘒήᰴరൻߒߚඨᓘᣇะ〒㔌㧘❑ゲߪᵹㅦ৻ቯߩቯᏱᵹࠇߦ߅

ߦ߅ߌࠆᵹㅦ߇߶߷หߓߦߥࠆࠃ߁ߦ⸳ቯߒߡ޿ࠆ㧚ᵹㅦ߇ߌࠆ▤ゲਛᔃᵹㅦ u 0 ߢήᰴరൻߒߚ୯ߢ޽ࠅ㧘⣂േߩฦ૏৻ቯߣߥࠆ߹ߢߩᄌൻߪ߶߷⋥✢⊛ߢ޽ࠆߎߣ߆ࠄ㧘ᑯ a ࠍ⋧ߦ߅ߌࠆᵹㅦಽᏓࠍታ✢ߢ␜ߒߡ޿ࠆ㧚࿑(a)ߢߪ㧘ߤߩ૏ో㐿ߔࠆ߹ߢߩㅦᐲᄌൻ߆ࠄᐔဋടㅦᐲ a ࠍ᳞߼ߚ㧚࿑ࠃࠅ⋧ߦ߅޿ߡ߽ᵹㅦಽᏓߩᒻ⁁ߪ᡼‛✢ߢ⋧ૃߢ޽ࠅ㧘૏⋧ㆃᐔဋടㅦᐲ a ߇ᄢ߈޿߶ߤ㧘⊒↢㔚ᵹߩᦨᄢ୯ I p ߩ⛘ኻ୯ࠇߪ߶ߣࠎߤ⷗ࠄࠇߥ޿㧚ߒ߆ߒ࿑(b)ߢߪ㧘వߦო㕙ㄭறߩߪᄢ߈ߊ㧘ߘߩᓟߪᵹㅦߦᲧ଀ߒߚቯᏱ⁁ᘒߦ⪭ߜ⌕޿ߡ޿ᵹㅦ߇Ⴧടߒ㧘ਛᔃㇱಽ߇ㆃࠇߡᄌൻߒߡ޿ࠆ㧚ߎߩߎߣ߆ࠆ㧚ࠄ㧘⣂േ๟ᵄᢙ߇Ⴧടߔࠆߣ㧘ო㕙ㄭறߩㅦᐲ൨㈩ߩᄌൻߪ

࿑ 4 ߪ㧘㔚ᵹߩᦨᄢ୯ I p ࠍᐔဋടㅦᐲ a ߦኻߒߡឬ޿ߚ߽ߩߢ㧘ߎࠇࠍ⷗ࠆߣ a ߩჇടߣߣ߽ߦ I p ߇߶߷⋥✢⊛ߦჇടߒߡ޿ࠆ㧚 a =0m/s ߦ߅ߌࠆ I p ߩ୯߇࿑ 2 ߩ 5 ⑽ᓟߩ
2୯ߣ߶߷หߓߢ޽ࠅ㧘ㅦᐲᄌൻ߇ዊߐ޿ߣ߈ߩ⊒↢㔚ᵹߪቯᏱ⁁ᘒߣ߶߷หߓߢ޽ࠆߣߺߥߖࠆߎߣ߇ࠊ߆ࠆ㧚ᵹ㊂ᄌൻߦᲧߴߡ૏⋧߇ㅴߺ㧘⊒↢㔚ᵹߩ૏⋧߽ㅴ߻ߎߣ߇
੍ᗐߐࠇࠆ㧚
ߘߎߢᵹ㊂ᄌേߣ⊒↢㔚ᵹߩ૏⋧Ꮕߦ⌕⋡ߒߡ㧘ታ㛎⚿ᨐࠍ⠨ኤߔࠆ㧚
3.2

ታ㛎ⵝ⟎࡮ታ㛎ᣇᴺታ㛎ߪ㧘࿑ 6(a)ߩᴤ࿶▤〝ࠍ↪޿ߡ᷹ቯߔࠆ㧚ࡐࡦࡊ߆ࠄฯ
3.

ᵹㅦ߇๟ᦼ⊛ߦᄌൻߔࠆߣ߈ߩᵹേᏪ㔚߈಴ߐࠇߚᴤߪ㧘ᴤ࿶ࡕ࡯࠲ߦࠃߞߡ㚟േߐࠇࠆ࿁ォᑼᱜᒏ

3.1⇇㕙ߩㅦᐲ൨㈩ߣ⊒↢㔚ᵹߩ㑐ଥᵄᵹࠇ⊒↢ེ(6)ࠍㅢࠅ㧘ౝᓘ 16mm ߩਥ▤〝ߣ᷹ቯㇱࠍㅢߞ

࿑ 4 ߩㅦᐲᄌൻࠍ઻߁ᵹࠇߦ↢ߓࠆ⊒↢㔚ᵹߪ㧘ᵹㅦߦᲧߚᓟᴤ࠲ࡦࠢߦᚯࠆ㧚࿁ォᑼᱜᒏᵄᵹࠇ⊒↢ེࠍ↪޿ࠆߎߣ଀ߒߚቯᏱᚑಽߦട߃㧘ᵹㅦ߇ᄌൻߔࠆߎߣߦࠃߞߡ↢ߓࠆߦࠃߞߡ㧘▤〝ߦ 30㨪400Hz ߩ㑆ߩછᗧߩ๟ᵄᢙߩ⣂േᵹࠇ㕖ቯᏱᚑಽ߇ടࠊߞߚ߽ߩߣ⠨߃ࠆߎߣ߇ߢ߈ࠆ㧚ᵹേᏪ㔚ࠍ૞ࠅ಴ߔ㧚᷹ቯㇱߦߪ㧘೨┨ߣหߓࠬ࠹ࡦ࡟ࠬ⵾✂ߣ㧘࿑߇⇇㕙ߢ⊒↢ߔࠆ⃻⽎ߢ޽ࠆߎߣࠍ⠨߃ࠆߣ㧘⇇㕙ߢߩㅦᐲ6(b)ߦ␜ߔ⋥ᓘ 2mm ߩⓣࠍหᔃ౞⁁ߦ 8 ୘㐿ߌߚࠬ࠹ࡦ࡟ࠬ

൨㈩ߩᄢ߈ߐߣᄌൻㅦᐲ߇㧘ᵹേᏪ㔚ߦᄢ߈ߊᓇ㗀ߔࠆߣ੍⵾᧼ࠍ↪޿㧘ᵹࠇߦ⋥੤ߔࠆࠃ߁ߦ⛘✼଻ᜬߒ㧘ᴤ߇㐿ญㇱᗐߐࠇࠆ㧚ࠍㅢㆊߔࠆߎߣߦࠃߞߡ↢ߓࠆ㔚ᵹࠍ᷹ቯߔࠆ㧚ᵹേᏪ㔚ߦ▤〝ౝߩᵹㅦߩඨᓘᣇะಽᏓߪ㧘ᵹㅦ߇৻ቯߩ႐วߪ᡼‛࿕ᶧ⇇㕙ㄭறߩᵹࠇ߇ᄢ߈ߊᓇ㗀ߒ㧘ߐࠄߦ࿑ 5 ߦ␜ߔࠃ߁

ಽᏓߦߥࠆ㧚ߒ߆ߒᵹㅦ߇๟ᦼ⊛ߦᄌൻߔࠆ႐วߪ㧘๟ᵄᢙߦ⣂േ๟ᵄᢙߦࠃߞߡㅦᐲ൨㈩߇ᄌൻߔࠆߎߣ߆ࠄ㧘એਅߩߦࠃߞߡ▤〝ඨᓘᣇะߦ૏⋧Ꮕ߇↢ߓࠆߎߣ߇⍮ࠄࠇߡ޿⸃ᨆߢߪᵹ〝ౝߩㅦᐲಽᏓ߇ផ᷹ߒ߿ߔ޿ࠬ࠹ࡦ࡟ࠬ⵾᧼

(5)ࠆ 㧚ᓟߦ␜ߔ࿑ 7 ߩᐔဋᵹㅦߩቯᏱᵹᚑಽߣᄌേᵹᚑಽߩ

ߩ᷹ቯ⚿ᨐࠍਛᔃߦ⠨ኤߔࠆ㧚ߐࠄߦᵹ〝ౝߩᵹࠇᣇะߩㅦ

28

32

12008

Rotary sinusoidal flow generator

MAMP

10 5 10Ǿ

1000

M

1200

Orifice flow meter(a) ᴤ࿶࿁〝(b) ᷹ቯㇱߩ⹦⚦(a) hydraulic circuit(b) detail of test section࿑ 6 ⣂േᵹࠇߦࠃࠆᵹേᏪ㔚᷹ቯ↪ታ㛎࿁〝
Fig.6 Experimental setup to measure flow electrification in hydraulic line.

first harmonics
synthesized harmonics

443

3ua m/sua m/sfirst harmonics
synthesized harmonics

21

2
1-0.15

-0.15

I nA

0-0.1

I nA

0-0.1
-0.2

-0.2

-0.25

-0.25
-0.3
0

1t/T
(a)

-0.3
02

f =40Hz

1t/T
(b)

2

f =190Hz࿑ 7 ⣂േᵹࠇߦ߅ߌࠆ⊒↢㔚ᵹߩ᷹ቯ⚿ᨐ
Fig.7 Currents detected from metal channels in pulsating flow.

ᐲಽᏓࠍ৻᭽ߦߔࠆߚ߼ߦ㧘᷹ቯㇱߣหߓᒻ⁁ߦടᎿߒߚ᏷

ဋᵹㅦࠍ ua ߣߒ㧘ߘߩ߁ߜቯᏱᵹᚑಽࠍ ua 㧘ᝄേᵹᚑಽࠍ10mm ߩࠬ࠹ࡦ࡟ࠬ⵾ߩ᧼ࠍ᷹ቯㇱߩ೨ᓟߦ㊀ߨวࠊߖߡข'ua ߣߔࠆ㧚ᴤ࿶▤〝ߪోߡࠣ࡜ࡦ࠼ߦធ࿾ߒߡ߅ࠅ㧘᷹ࠅઃߌࠆ㧚᷹ቯㇱߢ⊒↢ߒߚ㔚ᵹߪ㧘࿑ 1 ߣห᭽ߦ㔚᳇࿁〝ቯㇱࠍㅢㆊߔࠆᴤߩᐔဋᵹ㊂ߪ᷹ቯㇱਅᵹߦ⟎޿ߚࠝ࡝ࡈࠍ↪޿ߡ㔚࿶ߦᄌ឵ߒ㧘AD ᄌ឵ེࠍ੺ߒߡࠦࡦࡇࡘ࡯࠲ߦ

ࠖࠬᵹ㊂⸘ߢ㧘ᴤ᷷ߪ᷹ቯㇱ਄ᵹߩࠨ࡯ࡒࠬ࠲᷷ᐲ⸘ߢ᷹ቯ

ขࠅㄟࠎߢࡈ࡯࡝ࠛᄌ឵ߒ㧘Ⴧ᏷࿁〝ߩേ․ᕈࠍ⠨ᘦߒߡ⸃ߔࠆ㧚ታ㛎ਛߩᴤ᷷ߪࠝࠗ࡞ࠢ࡯࡜ߦࠃߞߡ৻ቯ᷷ᐲߦ଻ߟ㧚ᨆࠍⴕ߁㧚᷹ቯㇱ߆ࠄ 1200㨙㨙਄ᵹߣ㧘ߐࠄߦ 1000mm ਄ᵹ3.3ߦߘࠇߙࠇඨዉ૕࿶ജᄌ឵ེࠍขࠅઃߌߡ߅ࠅ㧘᷹ቯㇱࠍㅢ

࿑ 7 ߪ㧘ua ࠍ 2.4m/s(᷹ቯⓣౝߩ࡟ࠗࡁ࡞࠭ᢙߪ 42)㧘'ua

ࠆᄌേᵹ㊂ࠍ㧘ੑὐ㑆ߩ࿶ജᏅ߆ࠄᘠᕈᏅ࿶ᑼᄌേᵹ㊂᷹ቯ
(7)

ᴺ ࠍ↪޿ߡ᳞߼ࠆ㧚ᵹ㊂ࠍᵹ〝ᢿ㕙Ⓧߢഀߞߚᵹ〝ᢿ㕙ᐔ᷹ቯ⚿ᨐ

ࠍ1㨪1.5m/s ⒟ᐲߦ⸳ቯߒ㧘⣂േ๟ᵄᢙ f ࠍ(a)40Hz㧘
(b)190Hzߣߒߚᤨߩᵹㅦߣ㔚ᵹߩ᷹ቯ⚿ᨐߢ޽ࠆ㧚਄࿑߇ᵹ〝ᢿ㕙ᐔ

290

Ǎua
2m/s

-2-1

1

nA
0.05

-2-1

f =40Hz-1(b)f=140Hz

0

Ǎua
2m/s

1-2-0.05
(c)

1

Ǎua
2m/s

f =60HznA
0.05

f=190Hz0

Ǎua
2m/s

ǍI

nA0.05ǍI-20-0.05-0.05(a)f=60HzǍI

f=40Hz

ǍI

nA
0.05

-1

1-0.05

f =140Hz(d)f =190Hz࿑ 8 ᄌേᵹᚑಽߣ⊒↢㔚ᵹߩ㑐ଥ
Fig.8 Changes of flow velocity and currents in pulsating flow.
ᝄ᏷߇ᄢ߈ߊߥߞߡ޿ࠆ߇㧘ߎࠇߪ᷹ቯ▤〝ో૕ߩ๟ᵄᢙ․0ᕈߦࠃࠆ߽ߩߢ޽ࠆ㧚࿑ࠃࠅ㧘ᵹㅦ߇ᱜᒏᵄ⊛ߦᄌേߔࠆߣ㧘⊒↢㔚ᵹ߽หߓࠃ

I nA-0.1߁ߦᄌേߒߡ޿ࠆ㧚ᴤߣߩ⚵ߺวࠊߖߦ߅޿ߡࠬ࠹ࡦ࡟ࠬߪ

-0.2-0.3 SUS304
with 8 holes-0.4 VG46
ǰ=23͠
-0.5
01⽶ߦᏪ㔚ߒ㧘⊒↢㔚ᵹߪ࡟ࠗࡁ࡞࠭ᢙ߇ૐ޿㗔ၞߢߪᵹㅦߦ
Ყ଀ߔࠆߎߣ߆ࠄ㧘ᵹㅦᵄᒻߣ㔚ᵹᵄᒻߪㅒᣇะߦჇᷫߒ㧘

f=40Hzf=190Hz
23ua m/s

4․ߦ࿑(a)ߢߪ᣿ࠄ߆ߦߘߩ௑ะ߇⷗ࠄࠇࠆ㧚ߒ߆ߒ࿑(b)ࠍ⷗
ࠆߣ㧘ᵹㅦߣ㔚ᵹߩ㑆ߦᄢ߈ߥ૏⋧ߩߕࠇ߇⷗ࠄࠇࠆ㧚ߒ߆߽ᵹㅦᄌൻߦኻߒߡ㔚ᵹߩᄌൻߪㆃࠇߡ߅ࠅ㧘వߩ੍ᗐߣ෻
ኻߩ⚿ᨐߣߥߞߡ޿ࠆ㧚ߘࠇߙࠇ૏⋧Ꮕߪ㧘࿑(a)ߢߪ 7q⒟࿑ 9 ⣂േᵹࠇߣቯᏱᵹࠇߦ߅ߌࠆ⊒↢㔚ᵹߩᲧセᐲߢ޽ࠆߩߦኻߒ㧘࿑(b)ߢߪ 110qߦߥߞߡ޿ࠆ㧚߹ߚ࿑(b)Fig.9 Currents detected from metal channels in steady state flowߪᵹㅦߩᄌേᵹᚑಽߩᝄ᏷߇ᄢ߈޿ߦ߽߆߆ࠊࠄߕ㧘㔚ᵹߩand in pulsating flow.

ᝄ᏷ߪ߻ߒࠈዊߐߊߥߞߡ޿ࠆ㧚ߐࠄߦ࿑ 8 ߪ㧘ᵹㅦߣ㔚ᵹߩၮᧄᵄᚑಽߩᄌൻߩ㑐ଥࠍታဋᵹㅦ ua 㧘ਅ࿑߇᷹ቯ㔚ᵹ I ߢ޽ࠅ㧘᷹ቯାภࠍ๟ᵄᢙ⸃

✢ߢ㧘ਔ⠪ߩቯᏱߥ㑐ଥࠍ⎕✢ߢ␜ߒߚ࿑ߢ޽ࠆ㧚๟ᵄᢙ߇ᨆߒ㧘ၮᧄᵄᚑಽߩᤨ㑆ᄌൻࠍታ✢ߢ㧘ၮᧄᵄ߆ࠄ╙ਃ㜞⺞

40㧘60Hz ߢߪ㧘 'ua - 'I ߩ㑐ଥߪ߶߷⋥✢⊛ߢ㧘ਔ⠪ߪᲧᵄᚑಽ߹ߢࠍ↪޿ߡౣ⃻ߒߚᵄᒻࠍ⎕✢ߢឬ޿ߡ޿ࠆ㧚ᮮゲߪ㧘ᤨ㑆ࠍ⣂േ๟ᦼ T ߢήᰴరൻߒߡ޿ࠆ㧚ታ✢ߣ⎕✢ߩᒻ⁁ߪ⦟ߊวߞߡ߅ࠅ㧘ᵄᒻ߇߶߷ၮᧄᵄᚑಽߩߺ߆ࠄᚑߞߡ
޿ࠆߎߣ߇ࠊ߆ࠆ㧚࿑(a)ߦᲧߴߡ࿑(b)ߩᵹㅦߩᄌേᵹᚑಽߩ

଀ߒߡ޿ࠆࠃ߁ߦ⷗߃ࠆ߇㧘๟ᵄᢙ߇ 140Hz ߢߪ㧘ਔ⠪ߩ㑆ߩ૏⋧Ꮕ߇Ⴧടߒ㧘ᄢ߈ߥᬦ౞゠㆏ࠍឬߊࠃ߁ߦߥࠆ㧚

30

32
12008
ㅦᐲᄌൻࠍ઻߁ᴤߩᵹࠇߦ↢ߓࠆᵹേᏪ㔚⃻⽎ߩ᷹ቯ㧔㜞ᯅᥓࠄ㧕᷹ቯࠍⴕߞߚ๟ᵄᢙ▸࿐ߢ߶߷৻ቯ୯ࠍ␜ߒߡ޿ࠆ㧚ߎߩߎߣߪ㧘ૐ⣂േ๟ᵄᢙၞߢߪᵹㅦߣ㔚ᵹߩᄌൻ߇ቯᏱ․ᕈߦᴪ

1(ǍI/Ǎua)/(I/ua)ߞߡ޿ߡ㧘ਔ⠪ߩ㑆ߦㆃࠇ߇ή޿ߣߒߡ߽㧘๟ᵄᢙ߇޽ࠆ⒟ᐲએ਄(30Hz)ߦߥࠆߣ㧘๟ᵄᢙߦ㑐ଥߥߊ㔚ᵹᄌൻߪᵹㅦᄌൻߦኻߒ৻ቯᤨ㑆ㆃࠇࠆࠃ߁ߦߥࠆߎߣࠍᗧ๧ߔࠆ㧚

0.5એ਄ߩ⚿ᨐߪ㧘ᵹㅦᄌൻᤨߩ⊒↢㔚ᵹ߇ടㅦᐲߦᲧ଀ߒ㧘ߐࠄߦო㕙ㄭறߢߩㅦᐲ൨㈩߇๟ᵄᢙߩჇടߦኻߒߡᄢ߈ߊߥࠆߎߣ߆ࠄߪ⺑᣿ߢ߈ߥ޿㧚ߎߩේ࿃ߣߒߡ㧘⊒↢ߒߚ

0050100f Hz150㔚⩄ߦࠃߞߡ⇇㕙ㄭறߩ㔚⩄ኒᐲߩჇട߿㧘ዉ૕ߢ޽ࠆࠬ࠹200

ࡦ࡟ࠬო㕙ߣߩ㑆ߢ⊒↢ߔࠆ㔚⩄ߩ✭๺ࠍ⠨ᘦߒߡ޿ߥ޿

࿑ 10 ⣂േᵹࠇߦࠃߞߡ⊒↢ߔࠆ㔚ᵹߩ๟ᵄᢙ․ᕈ

ߎߣ߇᜼ߍࠄࠇࠆ㧚ߎߩߎߣ߆ࠄ㧘⣂േᤨߦ߅ߌࠆᵹേᏪ㔚Fig.10 Frequency characteristics of currents to the flow rate.

⃻⽎ࠍ⸃᣿ߔࠆߚ߼ߦ㧘࿕ᶧ⇇㕙ߩ㔚⩄ಽᏓߩᄌൻࠍ⠨ᘦߒߚ⸃ᨆ߇ᔅⷐߢ޽ࠆ㧚

104.

8

ᵹㅦᄌൻࠍ઻߁ᴤߩᵹࠇߦࠃߞߡࠬ࠹ࡦ࡟ࠬ⵾ᵹ〝ߦ⊒t ms6↢ߔࠆᵹേᏪ㔚ࠍ᷹ቯߒ㧘એਅߩ⚿ᨐࠍᓧߚ㧚(1) ᵹㅦ߇න⺞Ⴧടߔࠆ႐วߦߪ㧘ᵹㅦᄌൻ߇ㅦ޿߶ߤᄢ

4߈ߥㆊᷰ㔚ᵹ߇⊒↢ߒ㧘ߘߩᓟ৻ቯ୯߳ߣㄭߠߊ㧚

200

߹ߣ߼

(2) ⣂േᵹࠇߦ߅޿ߡߪ㧘ૐ⣂േ๟ᵄᢙၞߢߪㅦᐲߩᄌൻ
ߣߣ߽ߦ⊒↢㔚ᵹ߇ᄌൻߔࠆ㧚ߒ߆ߒ⣂േ๟ᵄᢙ߇Ⴧ

50100
f Hz150200ടߔࠆߣ㧘⊒↢㔚ᵹߪㆃࠇߡᄌൻߒ㧘୯߽ዊߐߊߥࠆ㧚࿑ 11 ᵹㅦᄌൻߦኻߔࠆ㔚ᵹߩㆃࠇᤨ㑆ᦨᓟߦ㧘੹࿁ታ㛎ⵝ⟎ߩ⸳⸘㧘⵾૞ߦ߅޿ߡߏዧജ޿ߚߛ

Fig.11 Delay time of current in pulsating flow.

޿ߚጟጊᄢቇᎿቇㇱᛛⴚ⡯ຬ ↰᧛⟵ᒾ᳁ߦᷓ↟ߩ⻢ᗧࠍ⸥ߔ㧚ᵹㅦᄌേ߇ή޿ቯᏱᵹࠇߦ߅ߌࠆᐔဋᵹㅦߣ⊒↢㔚ᵹߣෳ⠨ᢥ₂቟↰ᱜⴕ㧘ᓟ⮮ᷡ㧘ᄢਭ଻ੳ㧘᦬ጟᶻ㇢㧘ችᧄᤩ↵㧦㔚᳇ቇળ⺰ᢥ⹹ B, 105-3, (1985), 265-272.
2) 㕒㔚᳇ቇળ✬, 㕒㔚᳇ࡂࡦ࠼ࡉ࠶ࠢ, ࠝ࡯ࡓ␠, p.130-149.
(1998)
3) A. Sasaki, T. Yamamoto: Journal of the Society of Tribologists
and Lubrication Engineers, 55-9, (1999), 14-21.
4) 㜞ᯅᥓ㧘␸቞ᣂ㧘㣐የ⺈৻㧘⮮ේੱม㧦ᣣᧄᯏ᪾ቇળ⺰ᢥ㓸(C ✬),73-727, (2007), 871-878.
5) ᱞ⮮㜞⟵㧘ਛᩮൎᏆ㧦ᣣᧄᯏ᪾ቇળ⺰ᢥ㓸(B ✬), 46-404,(1980), 610-618.
6) 㣐የ⺈৻㧘ዊ⷏ᔘቁ㧦ᣣᧄᯏ᪾ቇળ⺰ᢥ㓸(╙ 2 ㇱ), 43376, (1977), 4574-4584.
7) 㒸ᕺ㕍㧘㣐የ⺈৻㧘㜞ᯅᥓ㧦ᣣᧄᯏ᪾ቇળ⺰ᢥ㓸(B ✬),72-720, (2006), 1920-1926.

ߩ㑐ଥߪ㧘࿑ 9 ߩ٤ශߩࠃ߁ߦߥࠅ㧘ᐔဋᵹㅦߦᲧ଀ߒߡ㔚1)

ᵹ߇⽶ߦჇടߒߡ޿ࠆ㧚ߎࠇߦኻߒ㧘⣂േ๟ᵄᢙ߇ 40Hz ߩ⚿ᨐߢ޽ࠆታ✢ߪቯᏱ․ᕈߦᴪߞߡᄌൻߒߡ޿ࠆ߇㧘๟ᵄᢙ߇ 190Hz ߦ߹ߢߥࠆߣ㧘ቯᏱ․ᕈߣߪ⇣ߥࠆ⚿ᨐߣߥߞߡ޿ࠆ㧚ቯᏱ․ᕈߩᵹㅦߣ⊒↢㔚ᵹߩᲧ I / ua ߦኻߔࠆ㧘⣂േᤨߩᄌേᵹᚑಽߣ㔚ᵹᄌൻߩᲧ 'I / 'ua ࠍ⣂േ๟ᵄᢙߦኻߒߡ
ឬߌ߫࿑ 10 ߩࠃ߁ߦߥࠆ㧚ߎߩ୯ߪ㧘⣂േ๟ᵄᢙ߇ 50Hz ೨ᓟߢߪ 1 ߦㄭ޿߇㧘⣂േ๟ᵄᢙ߇Ⴧടߔࠆߣ㧘ߘߩ୯ߪዊߐߊߥߞߡ޿ࠆ㧚ߐࠄߦᵹㅦᄌൻߦኻߔࠆ㔚ᵹᄌൻߩ૏⋧ㆃࠇࠍ๟ᵄᢙߢഀࠅ㧘ㆃࠇᤨ㑆ߣߒߡឬߌ߫࿑ 11 ߩࠃ߁ߦߥࠅ㧘- 6 -