速度変化を伴う油の流れに生じる流動帯電現象の測定

(1)

⺰

ᢥ

ㅦᐲᄌൻࠍ઻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 Metal

Channels 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

exponen-tially decreased until it leveled off with time, approaching a constant value. The smaller the time derivative of the

flow 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 phase

lag increased with the frequency, the time lag obtained by dividing the phase lag by the frequency turned out to be

al-most constant.

1. ߪߓ߼ߦ ᵹേᏪ㔚ߪ㧘࿕૕ߣᶧ૕ߩ⋧ኻㆇേߦࠃߞߡਔ⠪߇ㅒᭂᕈ ߦᏪ㔚ߔࠆ⃻⽎ߢ޽ࠅ㧘࿕ᶧ⇇㕙ߩ㔚᳇⊛ਛ๺߇⎕ࠄࠇߡ㔚 ⩄߇ಽ㔌ߒߡᏪ㔚ߒ㧘ߘߩᓟ㔚⩄߇ౣಽ㈩ߐࠇ৻ㇱߪ✭๺ߔ ࠆࡊࡠ࠮ࠬߣߒߡℂ⸃ߐࠇࠆ(1)㧚․ߦᴤߥߤߩ⛘✼ᕈᵹ૕ߢ ߪ⊒↢ߒߚ㔚⩄߇ౝㇱߦ⫾Ⓧߒ߿ߔ޿ߚ߼㧘㔚૏߇਄᣹ߒߡ ⛘✼⎕უߦࠃࠆ᡼㔚ࠍᒁ߈⿠ߎߒ㧘੐᡿ߩේ࿃ߣ߽ߥࠆߎߣ ߇ႎ๔ߐࠇߡ޿ࠆ(2)㧚ᵹേᏪ㔚ߦࠃࠆ੐᡿ࠍ㒐ᱛߔࠆߚ߼ߦ ߪ㧘㔚⩄ߩ⊒↢ࠍ㒐ߋߣߣ߽ߦ㧘㔚⩄ࠍㅦ߿߆ߦขࠅ㒰ߊߎ ߣ߇㊀ⷐߢ޽ࠆ㧚 ዉ૕ߢ޽ࠆ㊄ዻ⵾ᵹ〝ߪ㧘ㆡಾߦࠣ࡜ࡦ࠼ߦធ࿾ߒ㧘චಽ ߥ✭๺ᤨ㑆ࠍ⸳ߌࠆߎߣߦࠃߞߡ㧘㔚⩄ߩ⫾Ⓧࠍ㒐ߋߎߣ߇ ߢ߈ࠆ㧚ߒ߆ߒታ㓙ߦ㧘ࡈࠖ࡞࠲߿ࠝ࡝ࡈࠖࠬㇱߥߤߩ㊄ዻ ⵾ᯏེߦ߅޿ߡ߽ᵹേᏪ㔚ߩ⊒↢߇໧㗴ߣߥࠆߎߣ߇ႎ๔ ߐࠇߡ޿ࠆ(3)ߎߣ߆ࠄ⠨߃ࠆߣ㧘࿕ᶧߩ⚵ߺวࠊߖ߿ᵹㅦߛ ߌߢߥߊ㧘ᵹࠇߩ᭴ㅧ߇ᵹേᏪ㔚ߦᄢ߈ߊᓇ㗀ߒߡ޿ࠆߩߢ ߪߥ޿߆ߣផ᷹ߐࠇࠆ㧚ᚒޘߪ⒳ޘߩᒻ⁁ߩ㊄ዻ⵾ᵹ〝ߦ⊒ ↢ߒߚ㔚⩄ࠍ᷹ቯߒߡ߈ߚ⚿ᨐ㧘ᵹㅦߩᕆỗߥᄌൻߦࠃߞߡ ᄙߊߩ㔚ᵹ߇⊒↢ߔࠆߎߣ߇ࠊ߆ߞߚ(4)㧚ߎࠇߪ㧘⇇㕙ߩ㔚 ᳇⊛ࡃ࡜ࡦࠬ߇ᵹㅦߩᄌൻߦࠃߞߡ፣ࠇ㧘ᣂߚߥဋⴧࠍ଻ߟ ߦߪᤨ㑆ࠍⷐߔࠆߚ߼ߛߣ⠨߃ࠄࠇࠆ㧚ᵹ૕ᯏ᪾ߢߪ㧘⿠േ ஗ᱛ߿ࡐࡦࡊߩ⣂േߥߤߦࠃࠅ㧘ᵹࠇߩ⁁ᘒߪᏱߦᄌൻߒߡ ޿ࠆߣ⠨߃ࠄࠇࠆ㧚ߒߚ߇ߞߡ㧘ታᯏߦ߅ߌࠆᏪ㔚⃻⽎ࠍ⺞ ߴࠆ਄ߢߪ㧘ᵹㅦߩᄌൻߦࠃࠆᏪ㔚㊂ߩᄌൻߩᓇ㗀ࠍ⹦ߒߊ ⺞ߴߡ߅ߊߎߣ߇㊀ⷐߣߥߞߡߊࠆ㧚 ᧄ⎇ⓥߪᵹㅦߩᄌൻߦࠃߞߡ↢ߓࠆᏪ㔚㊂ࠍ᷹ቯߒ㧘ᵹㅦ ᄌൻ߇Ꮺ㔚㊂ߦਈ߃ࠆᓇ㗀ࠍ᣿ࠄ߆ߦߔࠆߎߣࠍ⋡⊛ߣߒ ߡ߅ࠅ㧘ታ㛎ߦࠃߞߡ⏕߆߼ߚ⚿ᨐߦߟ޿ߡႎ๔ߔࠆ㧚 2. ᵹㅦ߇ㆊᷰ⊛ߦᄌൻߔࠆߣ߈ߩᵹേᏪ㔚 2.1 ታ㛎ⵝ⟎࡮ታ㛎ᣇᴺ ታ㛎ߦ૶↪ߒߚⵝ⟎ߩ᭎ⷐࠍ࿑㧝ߦ␜ߔ㧚ࠣ࡜ࡦ࠼ߦធ࿾ߒ ߚࠬ࠹ࡦ࡟ࠬ⵾ߩ਄ㇱ࠲ࡦࠢA (ౝᓘ 210mm㧘㜞ߐ 600mm) ߦ⹜ᢱᶧ૕ࠍ౉ࠇߡ㔚⩄ࠍචಽ㒰෰ߔࠆߣߣ߽ߦ㧘ౝㇱߦข ࠅߟߌߚ㌃ࡄࠗࡊߦᕡ᷷ⵝ⟎߆ࠄߩ᳓ࠍᓴⅣߐߖߡ᷷ᐲࠍ ࠠ࡯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, Oka-yama University, 3-1-1 Tsushima-naka, OkaOka-yama, 700-8530, Japan㧚

** ᄢㅪᎿᬺᄢቇᯏ᪾ቇ㒮 (116034 ㆯካ⋭ᄢㅪᏒ↞੗ሶ඙シ Ꮏ⧞1 ภ)

Dailian Polytechnic University, #1 Qinggongyuan Dalian Liaoning, 116034, China

(2)

⺞ᢛߔࠆ㧚ታ㛎ߪ㧘ᑯa ࠍ㐿㐽ߒ㧘චಽ㒰㔚ߒߚᶧ૕ࠍ࿶❗ ⓨ᳇ߢ᛼ߒ಴ߒߡ᷹ቯㇱ(ౝᓘ 50mm)ࠍㅢㆊߐߖ㧘ਅㇱ࠲ࡦ ࠢB (ౝᓘ 260mm㧘㜞ߐ 450mm)ߦ⫾߃ࠆ㧚᷹ቯㇱߦߪ㧘ࠬ ࠹ࡦ࡟ࠬ⵾(SUS304)ߩ✂(㊎㊄ᓘ 0.11mm㧘㊎㊄㑆〒㔌 0.46m m㧘㐿ญ₸ 0.49)ࠍᵹࠇߦ⋥੤ߔࠆࠃ߁ߦ㧘ࠕࠢ࡝࡞᮸⢽(૕Ⓧ ᛶ᛫₸ 51014_ǡ_{m)ߦࠃߞߡ⛘✼଻ᜬߔࠆ㧚✂ࠍ᷹ቯㇱ౉ญ} 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⩄߇10Mǡߩᛶ᛫ࠍᵹ ࠇࠆߎߣߦࠃߞߡ↢ߓࠆ㔚࿶ᄌൻࠍ㧘OP ࠕࡦࡊ(LF356㧘౉ ജࠗࡦࡇ࡯࠳ࡦࠬ1012_ǡ_{)ߩ㕖෻ォჇ᏷࿁〝ࠍ↪޿ߡ⚂100୚} ߦჇ᏷ߒ㧘1ms ߏߣߦ AD ᄌ឵ེࠍ↪޿ߡ᷹ቯߒߚ⚿ᨐ߆ࠄ 㔚ᵹߩᤨ㑆ᄌൻࠍ᳞߼ࠆ㧚㔚ᵹߩ᷹ቯಽ⸃⢻ߪ⚂3pA㧘Ⴧ᏷ ࿁〝ߩࠞ࠶࠻ࠝࡈ๟ᵄᢙߪ1.5kHz ߢ޽ࠆ㧚หᤨߦ㧘ਅㇱ࠲ࡦ ࠢߦ⸳⟎ߒߚ⿥㖸ᵄᶧ㕙࠮ࡦࠨ(૏⟎ಽ⸃⢻ 0.172mm)㧘߹ߚ ߪ࡟࡯ࠩᄌ૏⸘(➅ࠅ㄰ߒ♖ᐲ 2Ǵm)ߢᴤ㕙ᄌ૏ࠍᬌ಴ߒ㧘ᵹ ㊂ࠍ᳞߼ࠆ㧚ታ㛎ߦߪᴤ࿶▤〝ߢ૶↪ߒߚ㋶‛ᴤ(VG46 ࡑࠪ ࡦᴤ)ࠍ↪޿ߡ߅ࠅ㧘૕Ⓧᛶ᛫₸

U

_vߪ25͠ߢ⚂ 1.21010_ǡ_m ߢ޽ߞߚ㧚 2.2 ᷹ቯ⚿ᨐ ᑯࠍ⍴ᤨ㑆ߢ㐿ߌᵹㅦࠍㆊᷰ⊛ߦᄌൻߐߖߚߣ߈ߩ᷹ቯ ⚿ᨐߩ৻଀ࠍ࿑2 ߦ␜ߔ㧚਄࿑ߪᴤ㕙ᄌൻ߆ࠄ᳞߼ߚ㐿ญㇱ ࠍㅢㆊߔࠆᴤߩᐔဋᵹㅦࠍ㧘ਅ࿑ߪ᷹ቯߒߚ㔚ᵹ୯ߩᄌൻࠍ㧘 ߘࠇߙࠇᵹࠇᆎ߼߆ࠄߩᤨ㑆ߦኻߒߡឬ޿ߡ޿ࠆ㧚ᵹࠇߪߓ ߼ߦᄢ߈ߥ⽶ߩ㔚ᵹ߇⊒↢ߒ㧘⚂5 ⑽ᓟߦᵹㅦߦᲧ଀ߒߚቯ Ᏹ⁁ᘒߩ୯߳ߣ⪭ߜ⌕޿ߡ޿ࠆ㧚᷹ቯ㔚ᵹ߇⽶ߢ޽ࠆߎߣ߆ ࿑㧝 ᵹേᏪ㔚ታ㛎ⵝ⟎

Fig.1 Experimental apparatus for flow electrification

measurement.

-0.1

0

0.1

0.2

0.3

0.4

0.5 u

a

m

/s

0

5

10

15 -6

-4

-2

0 I

nA

t s

a=0.030 m/s2 a=0.066 m/s2 a=0.11 m/s2 a=0.23 m/s2 a=0.52 m/s2

mesh

_VG46

࿑3 ㅦᐲᄌൻߦ઻߁⊒↢㔚ᵹߩᄌൻ

Fig.3 Profiles of generated current for gradual increase

of oil velocity through mesh.

-0.1

0

0.1

0.2

0.3

0.4

0.5 u

a

m

/s

0

5

10

15 -6

-4

-2

0 I

nA

t s

mech (SUS304)

VG46

ǰ

_=25͠

࿑2 ㆊᷰ⊛ߥᵹㅦᄌൻߦࠃߞߡ⊒↢ߒߚ㔚ᵹߩ᷹ቯ⚿ᨐ

Fig.2 Typical data obtained by test rig using mesh in an

abrupt go-and-stop flow.

(3)

ࠄ㧘ࠬ࠹ࡦ࡟ࠬ✂߇⽶ߦ㧘ᴤ߇ᱜߦᏪ㔚ߒߡ޿ࠆߎߣ߇ࠊ߆ ࠆ㧚 ᰴߦ㧘࿑1 ߩᑯ a ߩ㐿㐽ㅦᐲࠍᠲ૞ߒ㧘ᵹㅦࠍᄌ߃ߥ߇ࠄ ᷹ቯߒߚ⚿ᨐ߇࿑3 ߢ޽ࠆ㧚ߤߩ᷹ቯߦ߅޿ߡ߽㧘ቯᏱ⁁ᘒ ߦ߅ߌࠆᵹㅦ߇߶߷หߓߦߥࠆࠃ߁ߦ⸳ቯߒߡ޿ࠆ㧚ᵹㅦ߇ ৻ቯߣߥࠆ߹ߢߩᄌൻߪ߶߷⋥✢⊛ߢ޽ࠆߎߣ߆ࠄ㧘ᑯa ࠍ ో㐿ߔࠆ߹ߢߩㅦᐲᄌൻ߆ࠄᐔဋടㅦᐲ

a

ࠍ᳞߼ߚ㧚࿑ࠃࠅ ᐔဋടㅦᐲ

a

߇ᄢ߈޿߶ߤ㧘⊒↢㔚ᵹߩᦨᄢ୯

I

_pߩ⛘ኻ୯ ߪᄢ߈ߊ㧘ߘߩᓟߪᵹㅦߦᲧ଀ߒߚቯᏱ⁁ᘒߦ⪭ߜ⌕޿ߡ޿ ࠆ㧚 ࿑4 ߪ㧘㔚ᵹߩᦨᄢ୯

I

_pࠍᐔဋടㅦᐲ

a

ߦኻߒߡឬ޿ߚ ߽ߩߢ㧘ߎࠇࠍ⷗ࠆߣ

a

ߩჇടߣߣ߽ߦ

I

_p߇߶߷⋥✢⊛ߦ Ⴧടߒߡ޿ࠆ㧚

a

=0m/s2_ߦ߅ߌࠆ p

I

ߩ୯߇࿑2 ߩ 5 ⑽ᓟߩ ୯ߣ߶߷หߓߢ޽ࠅ㧘ㅦᐲᄌൻ߇ዊߐ޿ߣ߈ߩ⊒↢㔚ᵹߪቯ Ᏹ⁁ᘒߣ߶߷หߓߢ޽ࠆߣߺߥߖࠆߎߣ߇ࠊ߆ࠆ㧚 3. ᵹㅦ߇๟ᦼ⊛ߦᄌൻߔࠆߣ߈ߩᵹേᏪ㔚 3.1 ⇇㕙ߩㅦᐲ൨㈩ߣ⊒↢㔚ᵹߩ㑐ଥ ࿑4 ߩㅦᐲᄌൻࠍ઻߁ᵹࠇߦ↢ߓࠆ⊒↢㔚ᵹߪ㧘ᵹㅦߦᲧ ଀ߒߚቯᏱᚑಽߦട߃㧘ᵹㅦ߇ᄌൻߔࠆߎߣߦࠃߞߡ↢ߓࠆ 㕖ቯᏱᚑಽ߇ടࠊߞߚ߽ߩߣ⠨߃ࠆߎߣ߇ߢ߈ࠆ㧚ᵹേᏪ㔚 ߇⇇㕙ߢ⊒↢ߔࠆ⃻⽎ߢ޽ࠆߎߣࠍ⠨߃ࠆߣ㧘⇇㕙ߢߩㅦᐲ ൨㈩ߩᄢ߈ߐߣᄌൻㅦᐲ߇㧘ᵹേᏪ㔚ߦᄢ߈ߊᓇ㗀ߔࠆߣ੍ ᗐߐࠇࠆ㧚 ▤〝ౝߩᵹㅦߩඨᓘᣇะಽᏓߪ㧘ᵹㅦ߇৻ቯߩ႐วߪ᡼‛ ಽᏓߦߥࠆ㧚ߒ߆ߒᵹㅦ߇๟ᦼ⊛ߦᄌൻߔࠆ႐วߪ㧘๟ᵄᢙ ߦࠃߞߡ▤〝ඨᓘᣇะߦ૏⋧Ꮕ߇↢ߓࠆߎߣ߇⍮ࠄࠇߡ޿ ࠆ(5)㧚ᓟߦ␜ߔ࿑7 ߩᐔဋᵹㅦߩቯᏱᵹᚑಽߣᄌേᵹᚑಽߩ ୯ࠍᢥ₂(5)ߩᑼߦઍ౉ߒߡ⸘▚ߒߚ▤〝ඨᓘᣇะߩᵹㅦಽ Ꮣߪ㧘࿑5 ߩࠃ߁ߦߥࠆ㧚࿑(a)ߪ⣂േ๟ᵄᢙ

f

߇50Hz ߩ㧘 ࿑(b)ߪ500HzߩㅦᐲಽᏓߩ⚿ᨐߢ޽ࠆ㧚ᮮゲߪ▤〝ඨᓘ

r

₀ߢ ήᰴరൻߒߚඨᓘᣇะ〒㔌㧘❑ゲߪᵹㅦ৻ቯߩቯᏱᵹࠇߦ߅ ߌࠆ▤ゲਛᔃᵹㅦ

u

₀ߢήᰴరൻߒߚ୯ߢ޽ࠅ㧘⣂േߩฦ૏ ⋧ߦ߅ߌࠆᵹㅦಽᏓࠍታ✢ߢ␜ߒߡ޿ࠆ㧚࿑(a)ߢߪ㧘ߤߩ૏ ⋧ߦ߅޿ߡ߽ᵹㅦಽᏓߩᒻ⁁ߪ᡼‛✢ߢ⋧ૃߢ޽ࠅ㧘૏⋧ㆃ ࠇߪ߶ߣࠎߤ⷗ࠄࠇߥ޿㧚ߒ߆ߒ࿑(b)ߢߪ㧘వߦო㕙ㄭறߩ ᵹㅦ߇Ⴧടߒ㧘ਛᔃㇱಽ߇ㆃࠇߡᄌൻߒߡ޿ࠆ㧚ߎߩߎߣ߆ ࠄ㧘⣂േ๟ᵄᢙ߇Ⴧടߔࠆߣ㧘ო㕙ㄭறߩㅦᐲ൨㈩ߩᄌൻߪ ᵹ㊂ᄌൻߦᲧߴߡ૏⋧߇ㅴߺ㧘⊒↢㔚ᵹߩ૏⋧߽ㅴ߻ߎߣ߇ ੍ᗐߐࠇࠆ㧚 ߘߎߢᵹ㊂ᄌേߣ⊒↢㔚ᵹߩ૏⋧Ꮕߦ⌕⋡ߒߡ㧘ታ㛎⚿ᨐ ࠍ⠨ኤߔࠆ㧚 3.2 ታ㛎ⵝ⟎࡮ታ㛎ᣇᴺ ታ㛎ߪ㧘࿑6(a)ߩᴤ࿶▤〝ࠍ↪޿ߡ᷹ቯߔࠆ㧚ࡐࡦࡊ߆ࠄฯ ߈಴ߐࠇߚᴤߪ㧘ᴤ࿶ࡕ࡯࠲ߦࠃߞߡ㚟േߐࠇࠆ࿁ォᑼᱜᒏ ᵄᵹࠇ⊒↢ེ(6)ࠍㅢࠅ㧘ౝᓘ16mm ߩਥ▤〝ߣ᷹ቯㇱࠍㅢߞ ߚᓟᴤ࠲ࡦࠢߦᚯࠆ㧚࿁ォᑼᱜᒏᵄᵹࠇ⊒↢ེࠍ↪޿ࠆߎߣ ߦࠃߞߡ㧘▤〝ߦ30㨪400Hz ߩ㑆ߩછᗧߩ๟ᵄᢙߩ⣂േᵹࠇ ࠍ૞ࠅ಴ߔ㧚᷹ቯㇱߦߪ㧘೨┨ߣหߓࠬ࠹ࡦ࡟ࠬ⵾✂ߣ㧘࿑ 6(b)ߦ␜ߔ⋥ᓘ2mm ߩⓣࠍหᔃ౞⁁ߦ8 ୘㐿ߌߚࠬ࠹ࡦ࡟ࠬ ⵾᧼ࠍ↪޿㧘ᵹࠇߦ⋥੤ߔࠆࠃ߁ߦ⛘✼଻ᜬߒ㧘ᴤ߇㐿ญㇱ ࠍㅢㆊߔࠆߎߣߦࠃߞߡ↢ߓࠆ㔚ᵹࠍ᷹ቯߔࠆ㧚ᵹേᏪ㔚ߦ ࿕ᶧ⇇㕙ㄭறߩᵹࠇ߇ᄢ߈ߊᓇ㗀ߒ㧘ߐࠄߦ࿑5 ߦ␜ߔࠃ߁ ߦ⣂േ๟ᵄᢙߦࠃߞߡㅦᐲ൨㈩߇ᄌൻߔࠆߎߣ߆ࠄ㧘એਅߩ ⸃ᨆߢߪᵹ〝ౝߩㅦᐲಽᏓ߇ផ᷹ߒ߿ߔ޿ࠬ࠹ࡦ࡟ࠬ⵾᧼ ߩ᷹ቯ⚿ᨐࠍਛᔃߦ⠨ኤߔࠆ㧚ߐࠄߦᵹ〝ౝߩᵹࠇᣇะߩㅦ

0

0.5

1

0

1

2

3

4

f=50Hz

r/r

0

u/

u

0 Ǿ₌₀ Ǿ_=Ǹ/2 Ǿ_=Ǹ Ǿ_=3Ǹ/2

0

0.5

1

0

1

2

3

4

f=500Hz

r/r

0

u/

u

0 Ǿ=0 Ǿ=Ǹ/2 Ǿ=Ǹ Ǿ=3Ǹ/2 (a) f=50Hz (b) f=500Hz ࿑5 ⣂േᤨߩᵹㅦಽᏓߩᄌൻ

Fig.5 Velocity distribution in pulsating flow.

0

0.1

0.2

0.3

0.4

0.5

0.6 -6

-4

-2

0 a

m/s

2

I

p

nA

mesh (SUS304) ǰ_=25͠ ࿑4 ᐔဋടㅦᐲߣᦨᄢ㔚ᵹߣߩ㑐ଥ

Fig.4 Correlation between the peak value of current and accel-eration of oil flow.

(4)

ᐲಽᏓࠍ৻᭽ߦߔࠆߚ߼ߦ㧘᷹ቯㇱߣหߓᒻ⁁ߦടᎿߒߚ᏷ 10mm ߩࠬ࠹ࡦ࡟ࠬ⵾ߩ᧼ࠍ᷹ቯㇱߩ೨ᓟߦ㊀ߨวࠊߖߡข ࠅઃߌࠆ㧚᷹ቯㇱߢ⊒↢ߒߚ㔚ᵹߪ㧘࿑1 ߣห᭽ߦ㔚᳇࿁〝 ࠍ↪޿ߡ㔚࿶ߦᄌ឵ߒ㧘AD ᄌ឵ེࠍ੺ߒߡࠦࡦࡇࡘ࡯࠲ߦ ขࠅㄟࠎߢࡈ࡯࡝ࠛᄌ឵ߒ㧘Ⴧ᏷࿁〝ߩേ․ᕈࠍ⠨ᘦߒߡ⸃ ᨆࠍⴕ߁㧚᷹ቯㇱ߆ࠄ1200㨙㨙਄ᵹߣ㧘ߐࠄߦ 1000mm ਄ᵹ ߦߘࠇߙࠇඨዉ૕࿶ജᄌ឵ེࠍขࠅઃߌߡ߅ࠅ㧘᷹ቯㇱࠍㅢ ࠆᄌേᵹ㊂ࠍ㧘ੑὐ㑆ߩ࿶ജᏅ߆ࠄᘠᕈᏅ࿶ᑼᄌേᵹ㊂᷹ቯ ᴺ(7)ࠍ↪޿ߡ᳞߼ࠆ㧚ᵹ㊂ࠍᵹ〝ᢿ㕙Ⓧߢഀߞߚᵹ〝ᢿ㕙ᐔ ဋᵹㅦࠍ

u

_aߣߒ㧘ߘߩ߁ߜቯᏱᵹᚑಽࠍ

u

_a㧘ᝄേᵹᚑಽࠍ a

u

'

ߣߔࠆ㧚ᴤ࿶▤〝ߪోߡࠣ࡜ࡦ࠼ߦធ࿾ߒߡ߅ࠅ㧘᷹ ቯㇱࠍㅢㆊߔࠆᴤߩᐔဋᵹ㊂ߪ᷹ቯㇱਅᵹߦ⟎޿ߚࠝ࡝ࡈ ࠖࠬᵹ㊂⸘ߢ㧘ᴤ᷷ߪ᷹ቯㇱ਄ᵹߩࠨ࡯ࡒࠬ࠲᷷ᐲ⸘ߢ᷹ቯ ߔࠆ㧚ታ㛎ਛߩᴤ᷷ߪࠝࠗ࡞ࠢ࡯࡜ߦࠃߞߡ৻ቯ᷷ᐲߦ଻ߟ㧚 3.3 ᷹ቯ⚿ᨐ ࿑7 ߪ㧘

u

_aࠍ2.4m/s(᷹ቯⓣౝߩ࡟ࠗࡁ࡞࠭ᢙߪ 42)㧘

'

u

_a ࠍ1㨪1.5m/s⒟ᐲߦ⸳ቯߒ㧘⣂േ๟ᵄᢙ

f

ࠍ(a)40Hz㧘(b)190Hz ߣߒߚᤨߩᵹㅦߣ㔚ᵹߩ᷹ቯ⚿ᨐߢ޽ࠆ㧚਄࿑߇ᵹ〝ᢿ㕙ᐔ

0

1

2

3

4 u

a

m

/s

first harmonics synthesized harmonics

0

1

2 -0.3

-0.25

-0.2

-0.15

-0.1

t/T

I

nA

0

1

2

3

4 u

a

m

/s

first harmonics synthesized harmonics

0

1

2 -0.3

-0.25

-0.2

-0.15

-0.1

t/T

I

nA

(a)

f

=40Hz (b)

f

=190Hz ࿑7 ⣂േᵹࠇߦ߅ߌࠆ⊒↢㔚ᵹߩ᷹ቯ⚿ᨐ

Fig.7 Currents detected from metal channels in pulsating flow.

Rotary sinusoidal flow generator

AMP

Orifice flow meter

M

10 10

5

1000

1200

Ǿ (a) ᴤ࿶࿁〝 (b) ᷹ቯㇱߩ⹦⚦

(a) hydraulic circuit (b) detail of test section ࿑6 ⣂േᵹࠇߦࠃࠆᵹേᏪ㔚᷹ቯ↪ታ㛎࿁〝

(5)

ဋᵹㅦ

u

_a㧘ਅ࿑߇᷹ቯ㔚ᵹ

I

ߢ޽ࠅ㧘᷹ቯାภࠍ๟ᵄᢙ⸃ ᨆߒ㧘ၮᧄᵄᚑಽߩᤨ㑆ᄌൻࠍታ✢ߢ㧘ၮᧄᵄ߆ࠄ╙ਃ㜞⺞ ᵄᚑಽ߹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 ᝄ᏷߇ᄢ߈ߊߥߞߡ޿ࠆ߇㧘ߎࠇߪ᷹ቯ▤〝ో૕ߩ๟ᵄᢙ․ ᕈߦࠃࠆ߽ߩߢ޽ࠆ㧚 ࿑ࠃࠅ㧘ᵹㅦ߇ᱜᒏᵄ⊛ߦᄌേߔࠆߣ㧘⊒↢㔚ᵹ߽หߓࠃ ߁ߦᄌേߒߡ޿ࠆ㧚ᴤߣߩ⚵ߺวࠊߖߦ߅޿ߡࠬ࠹ࡦ࡟ࠬߪ ⽶ߦᏪ㔚ߒ㧘⊒↢㔚ᵹߪ࡟ࠗࡁ࡞࠭ᢙ߇ૐ޿㗔ၞߢߪᵹㅦߦ Ყ଀ߔࠆߎߣ߆ࠄ㧘ᵹㅦᵄᒻߣ㔚ᵹᵄᒻߪㅒᣇะߦჇᷫߒ㧘 ․ߦ࿑(a)ߢߪ᣿ࠄ߆ߦߘߩ௑ะ߇⷗ࠄࠇࠆ㧚ߒ߆ߒ࿑(b)ࠍ⷗ ࠆߣ㧘ᵹㅦߣ㔚ᵹߩ㑆ߦᄢ߈ߥ૏⋧ߩߕࠇ߇⷗ࠄࠇࠆ㧚ߒ߆ ߽ᵹㅦᄌൻߦኻߒߡ㔚ᵹߩᄌൻߪㆃࠇߡ߅ࠅ㧘వߩ੍ᗐߣ෻ ኻߩ⚿ᨐߣߥߞߡ޿ࠆ㧚ߘࠇߙࠇ૏⋧Ꮕߪ㧘࿑(a)ߢߪ 7q⒟ ᐲߢ޽ࠆߩߦኻߒ㧘࿑(b)ߢߪ 110qߦߥߞߡ޿ࠆ㧚߹ߚ࿑(b) ߪᵹㅦߩᄌേᵹᚑಽߩᝄ᏷߇ᄢ߈޿ߦ߽߆߆ࠊࠄߕ㧘㔚ᵹߩ ᝄ᏷ߪ߻ߒࠈዊߐߊߥߞߡ޿ࠆ㧚 ߐࠄߦ࿑8 ߪ㧘ᵹㅦߣ㔚ᵹߩၮᧄᵄᚑಽߩᄌൻߩ㑐ଥࠍታ ✢ߢ㧘ਔ⠪ߩቯᏱߥ㑐ଥࠍ⎕✢ߢ␜ߒߚ࿑ߢ޽ࠆ㧚๟ᵄᢙ߇ 40㧘60Hz ߢߪ㧘

'

u

_a-

'

I

ߩ㑐ଥߪ߶߷⋥✢⊛ߢ㧘ਔ⠪ߪᲧ ଀ߒߡ޿ࠆࠃ߁ߦ⷗߃ࠆ߇㧘๟ᵄᢙ߇140Hz ߢߪ㧘ਔ⠪ߩ㑆 ߩ૏⋧Ꮕ߇Ⴧടߒ㧘ᄢ߈ߥᬦ౞゠㆏ࠍឬߊࠃ߁ߦߥࠆ㧚

0

1

2

3

4 -0.5

-0.4

-0.3

-0.2

-0.1

0 SUS304

with 8 holes

VG46

ǰ

_=23͠

u

a

m/s

I

n

A

f=40Hz

f=190Hz

࿑9 ⣂േᵹࠇߣቯᏱᵹࠇߦ߅ߌࠆ⊒↢㔚ᵹߩᲧセ

Fig.9 Currents detected from metal channels in steady state flow and in pulsating flow.

-2

-1

1

2 -0.05

0.05

0 Ǎ

u

_a

Ǎ

I

nA

m/s

f=40Hz

-2

-1

1

2 -0.05

0.05

0 Ǎ

_u

_a

Ǎ

I

nA

m/s

f=60Hz

(a)

f

=40Hz (b)

f

=60Hz

-2

-1

1

2 -0.05

0.05

0 Ǎ

u

_a

Ǎ

I

nA

m/s

f=140Hz

-2

-1

1

2 -0.05

0.05

0 Ǎ

u

_a

Ǎ

I

nA

m/s

f=190Hz

(c)

f

=140Hz (d)

f

=190Hz ࿑8 ᄌേᵹᚑಽߣ⊒↢㔚ᵹߩ㑐ଥ

(6)

- 6 - ᵹㅦᄌേ߇ή޿ቯᏱᵹࠇߦ߅ߌࠆᐔဋᵹㅦߣ⊒↢㔚ᵹߣ ߩ㑐ଥߪ㧘࿑9 ߩ٤ශߩࠃ߁ߦߥࠅ㧘ᐔဋᵹㅦߦᲧ଀ߒߡ㔚 ᵹ߇⽶ߦჇടߒߡ޿ࠆ㧚ߎࠇߦኻߒ㧘⣂േ๟ᵄᢙ߇40Hz ߩ ⚿ᨐߢ޽ࠆታ✢ߪቯᏱ․ᕈߦᴪߞߡᄌൻߒߡ޿ࠆ߇㧘๟ᵄᢙ ߇190Hz ߦ߹ߢߥࠆߣ㧘ቯᏱ․ᕈߣߪ⇣ߥࠆ⚿ᨐߣߥߞߡ޿ ࠆ㧚 ቯᏱ․ᕈߩᵹㅦߣ⊒↢㔚ᵹߩᲧ

I /

u

_aߦኻߔࠆ㧘⣂േᤨߩ ᄌേᵹᚑಽߣ㔚ᵹᄌൻߩᲧ

'

I '

/

u

_aࠍ⣂േ๟ᵄᢙߦኻߒߡ ឬߌ߫࿑10 ߩࠃ߁ߦߥࠆ㧚ߎߩ୯ߪ㧘⣂േ๟ᵄᢙ߇ 50Hz ೨ ᓟߢߪ1 ߦㄭ޿߇㧘⣂േ๟ᵄᢙ߇Ⴧടߔࠆߣ㧘ߘߩ୯ߪዊߐ ߊߥߞߡ޿ࠆ㧚ߐࠄߦᵹㅦᄌൻߦኻߔࠆ㔚ᵹᄌൻߩ૏⋧ㆃࠇ ࠍ๟ᵄᢙߢഀࠅ㧘ㆃࠇᤨ㑆ߣߒߡឬߌ߫࿑11 ߩࠃ߁ߦߥࠅ㧘 ᷹ቯࠍⴕߞߚ๟ᵄᢙ▸࿐ߢ߶߷৻ቯ୯ࠍ␜ߒߡ޿ࠆ㧚ߎߩߎ ߣߪ㧘ૐ⣂േ๟ᵄᢙၞߢߪᵹㅦߣ㔚ᵹߩᄌൻ߇ቯᏱ․ᕈߦᴪ ߞߡ޿ߡ㧘ਔ⠪ߩ㑆ߦㆃࠇ߇ή޿ߣߒߡ߽㧘๟ᵄᢙ߇޽ࠆ⒟ ᐲએ਄(30Hz)ߦߥࠆߣ㧘๟ᵄᢙߦ㑐ଥߥߊ㔚ᵹᄌൻߪᵹㅦᄌ ൻߦኻߒ৻ቯᤨ㑆ㆃࠇࠆࠃ߁ߦߥࠆߎߣࠍᗧ๧ߔࠆ㧚 એ਄ߩ⚿ᨐߪ㧘ᵹㅦᄌൻᤨߩ⊒↢㔚ᵹ߇ടㅦᐲߦᲧ଀ߒ㧘 ߐࠄߦო㕙ㄭறߢߩㅦᐲ൨㈩߇๟ᵄᢙߩჇടߦኻߒߡᄢ߈ ߊߥࠆߎߣ߆ࠄߪ⺑᣿ߢ߈ߥ޿㧚ߎߩේ࿃ߣߒߡ㧘⊒↢ߒߚ 㔚⩄ߦࠃߞߡ⇇㕙ㄭறߩ㔚⩄ኒᐲߩჇട߿㧘ዉ૕ߢ޽ࠆࠬ࠹ ࡦ࡟ࠬო㕙ߣߩ㑆ߢ⊒↢ߔࠆ㔚⩄ߩ✭๺ࠍ⠨ᘦߒߡ޿ߥ޿ ߎߣ߇᜼ߍࠄࠇࠆ㧚ߎߩߎߣ߆ࠄ㧘⣂േᤨߦ߅ߌࠆᵹേᏪ㔚 ⃻⽎ࠍ⸃᣿ߔࠆߚ߼ߦ㧘࿕ᶧ⇇㕙ߩ㔚⩄ಽᏓߩᄌൻࠍ⠨ᘦߒ ߚ⸃ᨆ߇ᔅⷐߢ޽ࠆ㧚 4. ߹ߣ߼ ᵹㅦᄌൻࠍ઻߁ᴤߩᵹࠇߦࠃߞߡࠬ࠹ࡦ࡟ࠬ⵾ᵹ〝ߦ⊒ ↢ߔࠆᵹേᏪ㔚ࠍ᷹ቯߒ㧘એਅߩ⚿ᨐࠍᓧߚ㧚 (1) ᵹㅦ߇න⺞Ⴧടߔࠆ႐วߦߪ㧘ᵹㅦᄌൻ߇ㅦ޿߶ߤᄢ ߈ߥㆊᷰ㔚ᵹ߇⊒↢ߒ㧘ߘߩᓟ৻ቯ୯߳ߣㄭߠߊ㧚 (2) ⣂േᵹࠇߦ߅޿ߡߪ㧘ૐ⣂േ๟ᵄᢙၞߢߪㅦᐲߩᄌൻ ߣߣ߽ߦ⊒↢㔚ᵹ߇ᄌൻߔࠆ㧚ߒ߆ߒ⣂േ๟ᵄᢙ߇Ⴧ ടߔࠆߣ㧘⊒↢㔚ᵹߪㆃࠇߡᄌൻߒ㧘୯߽ዊߐߊߥࠆ㧚 ᦨᓟߦ㧘੹࿁ታ㛎ⵝ⟎ߩ⸳⸘㧘⵾૞ߦ߅޿ߡߏዧജ޿ߚߛ ޿ߚጟጊᄢቇᎿቇㇱᛛⴚ⡯ຬ ↰᧛⟵ᒾ᳁ߦᷓ↟ߩ⻢ᗧࠍ⸥ ߔ㧚 ෳ⠨ᢥ₂ 1) ቟↰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), 43-376, (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.

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࿑10 ⣂േᵹࠇߦࠃߞߡ⊒↢ߔࠆ㔚ᵹߩ๟ᵄᢙ․ᕈ Fig.10 Frequency characteristics of currents to the flow rate.

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࿑11 ᵹㅦᄌൻߦኻߔࠆ㔚ᵹߩㆃࠇᤨ㑆 Fig.11 Delay time of current in pulsating flow.