近畿大学次世代基盤技術研究所報告 Vol. 7（2016）65－71ᄇ㟝≉ᛶ࡜ᄇᏍෆ㒊ὶື࡟ཬࡰࡍ⇞ᩱᛶ≧ࡢᙳ㡪㧘ᶫ ㈗Ὧ*1㸪኱ᇉ ඃኴ*1㸪⏣➃ 㐨ᙪ*2 

Effect of Fuel Properties on Internal Nozzle Flow and Spray Characteristics
Takahiro TAKAHASHI*1, Yuta OGAKI*1 and Michihiko TABATA*2


In order to visualize the actual flow inside a diesel injection nozzle at high-pressure
injection, a model nozzle which has nozzle hole diameter with real size was made of sapphire.
Using the transparent nozzle and three kinds of fuel, the effects of the fuel properties on theinternal flow in the nozzle hole were investigated. The spray characteristics were observed byhigh-speed shadowgraph photography under realistic conditions. As the result, the fuel which
90% distillation temperature and kinematic viscosity are low, amount of cavitation generation isincreased. Therefore, the spray atomization and evaporation are promoted.
Keywords: Cavitation, Internal Nozzle Flow, Real Size Diesel Nozzle, Fuel Spray,Distillation Temperature, Fuel Viscosity, Bio Fuel, Gas Oil, Diesel Engine ࡣࡌࡵ࡟ᆅ⌫⎔ቃࡸ࢚ࢿࣝࢠၥ㢟ࡢほⅬ࠿ࡽ㸪࢞ࢯࣜࣥᶵ㛵࡜ẚ㍑ࡋ࡚⇕ຠ⋡ࡀ㧗ࡃ㸪 CO2 ᤼ฟ㔞ࡢᑡ࡞࠸ࢹ࢕࣮ࢮࣝᶵ㛵࡬ࡢ㍍Ἔ௦᭰⇞ᩱࡢ㐺⏝ࡀヨࡳࡽࢀ࡚࠸ࡿ㸬㍍Ἔ௦᭰⇞ᩱࡢ୍ࡘ࡜ࡋ࡚ࣂ࢖࢜⇞ᩱࡀᣲࡆࡽࢀࡿ㸬ࣂ࢖࢜⇞ᩱࡣ⇞↝࡟ࡼࡗ࡚᤼ฟࡉࢀࡿ CO2 㔞ࢆ㸪ཎᩱ࡛࠶ࡿ᳜≀⮬㌟ࡀගྜᡂ࡟ࡼࡗ࡚ᅛᐃ໬ࡍࡿ࣮࢝࣎ࣥࢽ࣮ࣗࢺࣛࣝࡢᴫᛕࢆ᭷ࡋ࡚࠾ࡾ㸪෌⏕ྍ⬟࡞⇞ᩱ࡜ࡋ࡚ὀ┠ࡉࢀ࡚࠸ࡿ㸬ࡋ࠿ࡋ㸪ࣂ࢖࢜⇞ᩱࡣ㍍Ἔ࡜ࡣ
⵨Ⓨ≉ᛶ࡞࡝ࡢ⇞ᩱᛶ≧ࡀ␗࡞ࡿ㸬ࡑࡢࡓࡵ㸪ࣂ࢖࢜⇞ᩱࡢࢹ࢕࣮ࢮࣝᶵ㛵࡬ࡢ㐺ྜᛶࢆ᳨ウࡍࡿᚲせࡀ࠶ࡿ㸬ࡲࡓ㸪⮬ື㌴⏝ࢹ࢕࣮ࢮࣝᶵ㛵࡜ࡋ࡚ᡂ❧ࡉࡏࡿ࡟ࡣ㸪ཝࡋ࠸᤼ฟ࢞ࢫつไ࡟ᑐᛂࡋ࡞ࡅࢀࡤ࡞ࡽ࡞࠸㸬ࡑࡢࡓࡵ㸪ࢡ࣮ࣜࣥ࠿ࡘ㧗ຠ⋡࡞ࣂ࢖࢜ࢹ࢕࣮ࢮࣝᶵ㛵ࡀồࡵࡽࢀ࡚࠸ࡿ㸬┤᥋ᄇᑕᘧࢹ࢕࣮ࢮࣝᶵ㛵࡟࠾࠸࡚㸪⇞↝ᨵၿࢆᅗࡿୖ࡛㸪ᄇ㟝≉ᛶ㸦ᚤ⢏໬㸪⵨Ⓨ㸧ࡀ㔜せ࡞ᅉᏊ࡛࠶ࡿ㸬ຍ࠼࡚㸪ᄇ㟝ࡢᚤ⢏໬࡟ࡣ㸪ᄇᑕࣀࢬࣝᄇᏍෆ㒊࡟⏕ࡌࡿ࢟ࣕࣅࢸ࣮ࢩࣙࣥࡀ῝ࡃ㛵ࢃࡗ࡚࠸ࡿࡇ࡜ࡀ
ሗ࿌ࡉࢀ࡚࠾ࡾ(1),(2)㸪ᄇᏍෆ㒊ὶື࡜ᄇ㟝≉ᛶ࡜ࡢ㛵ಀᛶࢆ᫂☜࡟ࡍࡿࡇ࡜ࡀ㔜せ࡛࠶ࡿ㸬 ࡋ࠿ࡋ㸪⌧ᅾࡢࢹ࢕࣮ࢮࣝᶵ㛵࡛ࡣ᤼ฟ࢞ࢫ≉ᛶᨵၿࡢࡓࡵ㸪ᑠᄇᏍᚄࡢᄇᑕࣀࢬࣝ࡟ࡼࡾ㸪⇞ᩱࢆ㧗ᅽ࡛ᄇᑕࡍࡿࡓࡵ㸪ᚤᑠ࡞ࣀࢬࣝᄇᏍෆ㒊࡛ࡣ㸪㧗㏿࠿ࡘ࢟ࣕࣅࢸ࣮ࢩࣙࣥࢆྵࢇࡔ」㞧࡞⌧㇟ࡀ㉳ࡁ࡚࠸ࡿ㸬ࡑࡢࡓࡵ㸪ᄇᏍෆ㒊ὶື࡟ࡘ࠸࡚ࡣ㸪ᚑ᮶ࡢ㏱᫂࡞ᣑ
኱ࣔࢹࣝ࡟ࡼࡿᐃᛶⓗホ౯ࡔࡅ࡛ࡣ㸪༑ศ࡞᝟ሗࡀᚓ
ࡽࢀ࡞࠸ࡓࡵ㸪ᐇᑍࡢᄇᑕࣀࢬࣝࡢෆ㒊ὶືࢆィ ࡍ
ࡿᚲせࡀ࠶ࡿ(3)㸬ࡲࡓ㸪ࡑࡢ⤖ᯝࡣࢩ࣑࣮ࣗࣞࢩࣙࣥ࡟ࡼࡿෆ㒊ὶືゎᯒࡢ᳨ド࡟ࡶ᭷ຠ࡛࠶ࡿ㸬ᮏ◊✲࡛ࡣ㸪ᄇᏍෆ㒊ὶື࡜ᄇ㟝≉ᛶ࡟╔┠ࡋ㸪㧗ᅽᄇᑕ࡟ࡶ⪏࠼࠺ࡿࢧࣇ࢓࢖࢔〇ᐇᑍ኱ࡢᄇᑕࣀࢬࣝࢆ〇సࡋ㸪ᄇᏍෆ㒊ὶືࡢྍど໬ィ ࢆヨࡳࡓ㸬ࡲࡓ㸪ᐇᶵ࡜ྠࡌ᮲௳ୗ࡛ࡢ⇞ᩱᄇ㟝ࡢ⵨Ⓨࢆࢩࣕࢻ࢘ࢢࣛࣇἲ࡟ࡼࡾほᐹࡋ㸪ࡇࢀࡽࡢᄇᏍෆ㒊ὶື࡜ᄇ㟝≉ᛶ࡟ཬࡰࡍ⇞ᩱᛶ≧ࡢᙳ㡪ࢆㄪ࡭ࡓ㸬 ౪ヨ⇞ᩱ౪ヨ⇞ᩱ࡟ࡣ㸪Ỉ⣲໬ฎ⌮ࢆ᪋ࡋࡓࣃࣛࣇ࢕ࣥ⣔ࣂ࢖࢜⇞ᩱ(Bio fuel)㸪JIS2 ྕ㍍Ἔ(Gas oil)㸪㧗ࢭࢱࣥ౯⇞ᩱ(Reference fuel㸪௨ୗ Ref. fuel)ࢆ౑⏝ࡋࡓ㸬ᅗ 1࡟ࡑࡢ⇞ᩱᛶ≧ࢆ♧ࡍ㸬ᕥᅗ࡟♧ࡍࡼ࠺㍍Ἔ࡜ẚ㍑ࡋ
ཎ✏ཷ௜ 2016 ᖺ 5 ᭶ 7 ᪥*1 ㏆␥኱Ꮫ኱Ꮫ㝔 ࢩࢫࢸ࣒ᕤᏛ◊✲⛉ ࢩࢫࢸ࣒ᕤᏛᑓᨷ㸦ࠛ739-2116 ᮾᗈᓥᕷ㧗ᒇ࠺ࡵࡢ㎶ 1 ␒㸧
*2 ㏆␥኱ᏛᕤᏛ㒊 ᶵᲔᕤᏛ⛉ ᩍᤵ㸪ḟୡ௦ᇶ┙ᢏ⾡◊✲ᡤ ᩍᤵ㸦ࠛ739-2116 ᮾᗈᓥᕷ㧗ᒇ࠺ࡵࡢ㎶ 1 ␒㸧E-mail tabata@hiro.kindai.ac.jp㐃⤡ඛ㸸⏣➃㐨ᙪ㸦◊✲௦⾲⪅㸧－ 65 －࡚㸪ࣂ࢖࢜⇞ᩱࡣ 90%⵨␃ ᗘࡀపࡃ㸪ࢭࢱࣥ౯ࡣྠ
➼࡛࠶ࡿ㸬ࡲࡓ Ref. fuel ࡣ㸪㏫࡟㸪㍍Ἔ࡟ 90%⵨␃
ᗘࡀ㏆ࡃ㸪㧗࠸ࢭࢱࣥ౯ࢆᣢࡘ⇞ᩱ࡛࠶ࡿ㸬
ᅗ 1 ࡢྑᅗࡣ㸪ྛ⇞ᩱࡢ 90%⵨␃ ᗘ࡜ື⢓ᗘࡢ㛵ಀࢆ♧ࡋ࡚࠶ࡿ㸬90%⵨␃ ᗘࡀ㧗ࡃ࡞ࡿ࡟ᚑ࠸㸪ື⢓ᗘࡀ㧗ࡃ࡞ࡗ࡚࠸ࡿࡇ࡜ࡀศ࠿ࡿ㸬
5Ref. fuelGas oil320

Kinematic viscosity (@30deg.C) Ȟ [mm2/s]

90% distillation temperature T90 [deg.C]

360

280

Bio fuel

240

Ref. fuel4

Gas oil3ࢺࣛࣜࣥ࡜ࢸࣞࣅࣥἜࡢΰྜ⇞ᩱࢆ౑⏝ࡋࡓሙྜࡢ⤖ᯝ࡛࠶ࡿ㸬࡞࠾㸪ΰྜ⇞ᩱࡢᛶ≧ࡣ㍍Ἔ࡜࡯ࡰྠ୍࡛
࠶ࡿ㸬ࣞ࢖ࣀࣝࢬ┦ఝ๎࡟ᇶ࡙ࡁ㸪10 ಸࣔࢹࣝ࡟࠾ࡅ
ࡿᄇᑕᅽຊ 0.25㸪0.5㸪0.75 [MPa]ࡣ㸪ࡑࢀࡒࢀᐇᶵࣀ
ࢬࣝ࡟࠾ࡅࡿᄇᑕᅽຊ 77㸪154㸪230 [MPa]࡟┦ᙜࡋ࡚࠸ࡿ㸬ᄇᏍෆ࡛㯮ࡃ෗ࡗ࡚࠸ࡿࡢࡀ࢟ࣕࣅࢸ࣮ࢩࣙࣥ
࡟ࡼࡿẼἻࡀᏑᅾࡍࡿ㡿ᇦ࡛࠶ࡾ㸪ᄇᑕᅽຊ࡟ᕪ␗ࡀ
࠶ࡿࡀ㸪ᐇᑍࣔࢹ࡛ࣝࡢᄇᏍෆ㒊ࡢὶື≧ែࡣ㸪ᣑ኱ࣔࢹ࡛ࣝࡢࡑࢀ࡜ᐃᛶⓗ࡟୍⮴ࡋ࡚࠸ࡿࡇ࡜ࡀศ࠿ࡿ㸬ᚑࡗ࡚㸪ᮏᐇ㦂⿦⨨࡟ࡼࡾᐇᶵࣀࢬࣝෆࡢὶື≧ែࢆྍど໬ྍ⬟࡛࠶ࡿ࡜⪃࠼ࡽࢀࡿ㸬2

Bio fuel
1

200
5060

70

80

Cetane number [-]

90200

240

280

T90 [deg.C]

ᅗ 1㸬Fuel properties

320

360

ᅗ 2㸬Configuration of transparent nozzle ᄇᏍෆ㒊ὶືࡢィ  ᐇᑍ኱ྍど໬ᄇᑕࣀࢬࣝࢆ⏝࠸ࡓᐇ㦂⿦⨨ ᅗ 2 ࡟ࣀࢬࣝᄇᏍෆ㒊ࡢྍど໬࡟⏝࠸ࡓࢧࣇ࢓࢖࢔〇ࣀࢬࣝඛ➃㒊ࢆ♧ࡍ㸬ᄇᏍᚄ 0.12 [mm]㸪ᄇᏍ㛗ࡉ
1.84 [mm]࡛㸪ගᏛⓗྍど໬ほᐹࢆᐜ᫆࡟⾜࠺ࡓࡵ࡟ 2ᄇᏍ㸦ᄇᑕゅ 140 [deg.]㸧࡜ࡋࡓ㸬ᐇᶵᄇᑕࣀࢬࣝඛ➃㒊ศ࡟◊๐ຍᕤࢆ᪋ࡋ㸪ࢧࣇ࢓࢖࢔〇ࣀࢬࣝඛ➃㒊ࢆྲྀࡾ௜ࡅࡿࡇ࡜࡛ᄇᑕࣀࢬࣝඛ➃㒊ࢆྍど໬ࡋࡓ㸬 ᅗ 3 ࡟ࣀࢬࣝᄇᏍෆ㒊ὶືྍど໬ᐇ㦂⿦⨨ࡢᴫ␎ࢆ♧ࡍ㸬ᮏᐇ㦂⿦⨨࡟ࡼࡾ㸪㧗 㧗ᅽሙࢆᙧᡂࡍࡿࡇ࡜
ࡀྍ⬟࡛࠶ࡿࡀ㸪㧗 㧗ᅽሙ࡛ࡢィ ࡟ࡘ࠸࡚ࡣ㸪㞺ᅖẼࡢᐦᗘᕪ࡟ࡼࡿᒅᢡ⋡ࡢኚື࡟ࡼࡾ⏬㠃࡟ᦂࡽࡂࡀ⏕ࡌ㸪Ⰻዲ࡞⏬ീࡀᚓࡽࢀ࡞࠿ࡗࡓ㸬ࡋࡓࡀࡗ࡚㸪௒ᅇࡢィ ࡣ㞺ᅖẼᅽຊࢆ኱Ẽᅽୗ࡛⾜ࡗࡓ㸬⇞ᩱᄇᑕ࡟ࡣࢥ࣮ࣔࣥࣞࣝᘧ㟁Ꮚไᚚ⇞ᩱᄇᑕ⿦⨨ࢆ⏝࠸㸪ᄇᑕᮇ㛫ࢆ 2.0 [ms] ࡜ࡋࡓ㸬ᄇᏍෆ㒊ὶືࡢ᧜ᙳ࡟ࡣ㸪ග※࡟㐃⥆Ⓨ᣺ࡢ Ar+࣮ࣞࢨࢆ⏝࠸㸪࢚ࣥࢪࣥ࣊ࢵࢻഃ㠃࡟ᑐྥࡋ࡚タ⨨ࡋࡓ▼ⱥ࢞ࣛࢫ❆ࢆ㏻ࡋ࡚㸪ᣑ኱ගᏛ⿦⨨ࢆ⿦╔ࡋࡓ㧗㏿ᗘ࣓࢝ࣛ(᧜ᙳ㏿ᗘ40,000 [fps])࡟ࡼࡾ㸪⫼ᬒᩓ஘ග᧜ᙳࢆ⾜ࡗࡓ㸬 ᅗ 4 ࡟ࣀࢬࣝᄇᏍෆ㒊ࡢྍど໬⏬ീࡢ୍౛ࢆ♧ࡍ㸬ᅗ୰(a)ࡣᅗ 2 ࡟♧ࡋࡓྍど໬ࣀࢬࣝཬࡧ㍍Ἔࢆ⏝࠸ࡓሙྜࡢᄇᑕᅽຊࡢᙳ㡪ࢆ♧ࡋ࡚࠸ࡿ㸬࠸ࡎࢀࡶ㸪㔪ᘚࡀࣇࣝࣜࣇࢺ࡟㐩ࡋ࡚࠸ࡿᮇ㛫ࡢ⏬ീ࡛࠶ࡿ㸬(b)ࡣ㸪ᐇᶵࣀࢬࣝᄇᏍ㒊ࢆ 10 ಸ࡟ᣑ኱ࡋࡓ(ᄇᏍᚄ 1.2 [mm]㸪ᄇᏍ㛗ࡉ 8.43 [mm])࢔ࢡࣜࣝ〇ࡢ㏱᫂࡞ࣀࢬࣝཬࡧࢸ

ᅗ 3㸬Experimental apparatus for visualization ofinternal flow in nozzle hole

ᅗ 4㸬Comparative examples of internal flow in nozzle
hole by difference of nozzle geometry－ 66 －ᄇᏍෆ㒊ὶື࡟ཬࡰࡍ⇞ᩱᛶ≧ࡢᙳ㡪 ᅗ 5 ࡟ᄇᑕᅽຊ Pinj=30㸪100 [MPa]࡛㸪ᖖ ኱Ẽᅽ㞺ᅖẼ୰࡬ᄇᑕࡋࡓ㝿ࡢ㸪ᄇᑕึᮇ࡟࠾ࡅࡿࣀࢬࣝᄇ
Ꮝෆ㒊ࡢྍど໬⏬ീࢆ♧ࡍ㸬㟢ග᫬㛫ࡣ㸪0.5 [μs]࡛࠶
ࡿ㸬ࡲࡓ㸪ࢧࢵࢡෆࡀ㯮ࡃྲྀᚓࡉࢀ࡚࠸ࡿࡢࡣ㸪ࢧࢵࢡࡢᙧ≧࡟㉳ᅉࡍࡿᒅᢡ⋡ࡢᕪ␗࡟ࡼࡿࡶࡢ࡛࠶ࡿ㸬
ᅗ 5 ࡼࡾ㸪Pinj=30 [MPa]ࡢሙྜ㸪ࣂ࢖࢜⇞ᩱࡣᄇᑕ㛤ጞ┤ᚋ㸦t=0.025 [ms]㸧࠿ࡽᄇᏍධཱྀ௜㏆࡛࢟ࣕࣅࢸ
࣮ࢩࣙࣥࡀⓎ⏕ࡋ㸪᫬㛫ࡢ⤒㐣࡟క࠸࢟ࣕࣅࢸ࣮ࢩࣙࣥ㡿ᇦࡀᣑ኱ࡋ㸪t=0.1 [ms]࡟ࡣᄇᏍฟཱྀࡲ࡛㐩ࡋ࡚࠸ࡿ㸬㍍Ἔࡣ㸪࢟ࣕࣅࢸ࣮ࢩࣙࣥࡀ t=0.05 [ms] ࡛Ⓨ⏕ࡋ㸪ࡑࡢ㡿ᇦࡀᣑ኱ࡍࡿ㸬ࡋ࠿ࡋ Ref. fuel ࡣ t= 0.075[ms]࡟ᄇᏍධཱྀ௜㏆࡛࢟ࣕࣅࢸ࣮ࢩࣙࣥࡀⓎ⏕ࡋ࡚࠸ࡿࡀ㸪ࡑࡢ㡿ᇦࡣᄇᏍฟཱྀࡲ࡛㐩ࡋ࡚࠸࡞࠸㸬ࡇࢀࡽࡢせᅉ࡜ࡋ࡚ࡣ㸪ࣂ࢖࢜⇞ᩱࡣ 90%⵨␃ ᗘࡀపࡃ㸪ື⢓ᗘࡀప࠸ࡓࡵ࡟㸪పᄇᑕᅽຊ࡛ࡶᐜ᫆࡟ᄇᏍධཱྀ࡛ᅽຊ㝆ୗࡀ⏕ࡌࡿ㸬ࡑࢀ࡟ᑐࡋ㸪Ref. fuel ࡣ 90%⵨␃ ᗘ࡜ື⢓ᗘࡀ㧗ࡃ㸪ᅽຊ㝆ୗࡀᢚไࡉࢀࡿ㸬ࡑࡢࡓࡵ㸪ᄇᑕึᮇ࡟࠾࠸࡚ࡣ㸪ື⢓ᗘࡢቑຍ࡟క࠸ᄇᏍ
ධཱྀ࡛࢟ࣕࣅࢸ࣮ࢩࣙࣥࡀⓎ⏕ࡍࡿ᫬ᮇࡣ㐜ᘏࡍࡿ࡜⪃࠼ࡽࢀࡿ㸬ᄇᑕᅽຊࡢ㧗࠸ Pinj=100 [MPa]ࡢሙྜ㸪t= 0.05 [ms]࡛ࡣ㸪 90%⵨␃ ᗘ࡜ື⢓ᗘࡢ㧗࠸ Ref. fuel ࡛ࡣ㸪࢟ࣕࣅࢸ࣮ࢩࣙࣥࡀᄇᏍධཱྀ࡟Ⓨ⏕ࡋ࡚࠸ࡿࡢࡀ☜ㄆ࡛ࡁࡿࡀ㸪ࣂ࢖࢜⇞ᩱ㸪㍍Ἔ࡛ࡣࡍ࡛࡟ᄇᏍฟཱྀ㏆ࡃ࡟࢟ࣕࣅࢸ࣮ࢩࣙࣥ㡿ᇦࡣᣑ኱ࡋ࡚࠸ࡿ㸬ࡑࡢᚋ㸪
t=0.075 [ms]࡛ࡣ࠸ࡎࢀࡢ⇞ᩱࡶ࢟ࣕࣅࢸ࣮ࢩࣙࣥ㡿ᇦࡀᄇᏍฟཱྀ࡬㐩ࡍࡿ㸬ࡇࢀࡣ㸪ᄇᑕᅽຊࡢቑຍ࡟ࡼࡾ㸪࢟ࣕࣅࢸ࣮ࢩࣙࣥࡢⓎ⏕ࡀ┦ᑐⓗ࡟ࣀࢬࣝᄇᏍෆ㒊ὶ㏿ࡢᙳ㡪࡟ᨭ㓄ࡉࢀࡿࡓࡵ࡛࠶ࡿ㸬ࡑࡢࡓࡵ㸪⇞ᩱᛶ≧ࡢ㐪࠸࡟ࡼࡿᙳ㡪ࡀᑡ࡞ࡃ࡞ࡾ㸪࢟ࣕࣅࢸ࣮ࢩࣙࣥ㡿ᇦࡀᄇᏍฟཱྀ࡬㐩ࡍࡿ᫬ᮇࡢᕪࡀ┦ᑐⓗ࡟⦰ᑠࡋࡓࡶࡢ࡜⪃࠼ࡽࢀࡿ㸬 ࢟ࣕࣅࢸ࣮ࢩࣙࣥࡢⓎ⏕≧ἣࢆᐃ㔞ⓗ࡟ホ౯ࡍࡿࡓࡵ㸪ᄇᏍෆ㒊㡿ᇦࡢࡳࢆᑐ㇟࡜ࡋ㸪⏬ീ㍤ᗘࡢᖹᆒ್
ࢆ⟬ฟࡋࡓ㸬ࡑࡢ⤖ᯝࢆᅗ 6 ࡟♧ࡍ㸬࡞࠾㸪⫼ᬒ㍤ᗘ
ࡢ㐪࠸ࢆྲྀࡾ㝖ࡃࡓࡵ㸪ᄇᑕᮇ㛫୰ࡢ⏬ീ㍤ᗘࡢᖹᆒ
㍤ᗘࡢ᭱኱ᖹᆒ್࡛↓ḟඖ໬ࡋ࡚࠶ࡿ㸬ᅗ 6 ࡼࡾ㸪
Pinj=30 [MPa]ࡢሙྜ㸪ᅗ 5(a)࡟♧ࡋࡓྍど໬⏬ീ࠿ࡽࡶ᫂ࡽ࠿࡛࠶ࡿࡀ㸪ࣂ࢖࢜⇞ᩱࡣᄇᑕ᪩ᮇ࡟ᖹᆒ㍤ᗘࡀᛴ⃭࡟పୗࡋ࡚࠾ࡾ㸪᪩ᮇ࡟࢟ࣕࣅࢸ࣮ࢩࣙࣥࡀⓎ⏕ࡋ㸪࢟ࣕࣅࢸ࣮ࢩࣙࣥ㡿ᇦࡀᛴ㏿࡟ᣑ኱ࡍࡿࡇ࡜ࡀ
ศ࠿ࡿ㸬㍍Ἔࡶ᪩ᮇ࡟ᖹᆒ㍤ᗘࡀᛴ⃭࡟పୗࡋ࡚࠸ࡿ
ࡀ㸪ࡑࡢ໙㓄ࡣࣂ࢖࢜⇞ᩱࡼࡾࡶ⦆ࡸ࠿࡛࠶ࡿ㸬ࡋ࠿ࡋ㸪Ref. fuel ࡣࣂ࢖࢜⇞ᩱࡸ㍍Ἔ࡜ẚ㍑ࡋ࡚㸪ᖹᆒ㍤ᗘࡀ⦆ࡸ࠿࡟పୗࡋ࡚࠾ࡾ㸪ࡲࡓ㸪ᄇᑕᮇ㛫୰ࡢᖹᆒ㍤ᗘࡀ㧗ࡃ㸪࢟ࣕࣅࢸ࣮ࢩࣙࣥࡢⓎ⏕ཬࡧⓎ㐩ࡀᢚไࡉࢀ࡚࠸ࡿࡇ࡜ࡀศ࠿ࡿ㸬ᄇᏍෆ㒊ࡢᖹᆒ㍤ᗘࡀపୗ
ࡍࡿࡇ࡜ࡣᄇᏍෆ㒊ࡢ࢟ࣕࣅࢸ࣮ࢩࣙࣥⓎ⏕㔞ࡀከ࠸ࡇ࡜ࢆ♧ࡋ࡚࠾ࡾ㸪⇞ᩱࡢ 90%⵨␃ ᗘࡀపࡃ㸪ື⢓ᗘࡀప࠸࡯࡝㸪࢟ࣕࣅࢸ࣮ࢩࣙࣥࡢⓎ⏕㔞ࡀከࡃ࡞ࡿࡇ࡜ࡀᐃ㔞ⓗ࡟ศ࠿ࡿ㸬 ᄇᑕᅽຊࡢ㧗࠸ Pinj=100 [MPa]ࡢሙྜ㸪࢟ࣕࣅࢸ࣮ࢩ
ࣙࣥࡢⓎ⏕ࡀ┦ᑐⓗ࡟ࣀࢬࣝᄇᏍෆ㒊ὶ㏿ࡢᙳ㡪࡟ᨭ㓄ࡉࢀࡿࡓࡵ㸪Pinj=30 [MPa]࡜ẚ㍑ࡋ࡚㸪࠸ࡎࢀࡢ⇞ᩱࡶᄇᑕ᪩ᮇ࠿ࡽ࢟ࣕࣅࢸ࣮ࢩࣙࣥࡢⓎ⏕㔞ࡀከ࠸ࡓࡵ㸪ᖹᆒ㍤ᗘࡀᛴ⃭࡟పୗࡋ࡚࠸ࡿ㸬ᅗ 5 (b)࡟♧ࡋࡓ
ྍど໬⏬ീ࠿ࡽࡶ᫂ࡽ࠿࡞࡜࠾ࡾ㸪㧗ᅽᄇᑕ᮲௳࡛ࡶ㸪90%⵨␃ ᗘ࡜ື⢓ᗘࡢ኱ࡁ࠸ Ref. fuel ࡀ㸪ࣂ࢖࢜⇞ᩱ㸪㍍Ἔ࡜ẚ㍑ࡋ࡚㸪ᄇᏍෆ㒊ࡢᖹᆒ㍤ᗘࡀ㧗ࡃ㸪᫂ࡽ࠿࡟㸪࢟ࣕࣅࢸ࣮ࢩࣙࣥⓎ⏕㔞⮬యࡣᑡ࡞࠸ࡇ࡜ࡀศ࠿ࡿ㸬㧗ᅽᄇᑕ࡟࠾࠸࡚ࡶ㸪⇞ᩱࡢ 90%⵨␃ ᗘ࡜ື⢓ᗘࡢపୗ࡟క࠸㸪࢟ࣕࣅࢸ࣮ࢩࣙࣥⓎ⏕㔞ࡀከࡃ࡞ࡿࡶࡢ࡜⪃࠼ࡽࢀࡿ㸬 ᄇᏍฟཱྀ࡜ᄇᏍฟཱྀࡼࡾ 1 [mm] 㞳ࢀࡓ఩⨨࡟࠾ࡅࡿᄇ㟝እ⦕࡜ࡢ࡞ࡍゅࢆᄇ㟝ゅ࡜ᐃ⩏ࡋ㸪ᄇᑕࣀࢬࣝ
ฟཱྀࡢᄇ㟝ゅࢆ ᐃࡋࡓ⤖ᯝࢆᅗ 7 ࡟♧ࡍ㸬࠸ࡎࢀࡢ⇞ᩱࡶᄇᑕᅽຊࡀ㧗ࡃ࡞ࡿ࡜ᄇᑕ┤ᚋࡢᄇ㟝ゅࡀ኱ࡁࡃ࡞ࡗ࡚࠸ࡿ㸬ࡇࢀࡣᄇᑕᅽຊࡢቑຍ࡟క࠸࢟ࣕࣅࢸ
࣮ࢩࣙࣥࡢⓎ⏕ࡀಁ㐍ࡉࢀࡿࡇ࡜࡟ࡼࡾ㸪࢟ࣕࣅࢸ࣮
ࢩࣙࣥẼἻࢆྵࢇࡔᄇὶࡀᄇᑕࡉࢀࡓࡓࡵ࡛࠶ࡿ࡜⪃࠼ࡽࢀࡿ㸬ᅗ 7 (a)ࡣ㸪ᄇᑕᅽຊ Pinj=30 [MPa]ࡢሙྜࡢ
⤖ᯝ࡛࠶ࡿ㸬90%⵨␃ ᗘ࡜ື⢓ᗘࡢ㧗࠸㍍Ἔࡸ Ref.
fuel ࡜ẚ㍑ࡋ࡚㸪ࣂ࢖࢜⇞ᩱ࡛ࡣ㸪ᄇᑕᚋ t=0.25 [ms]࡛ᄇ㟝ゅࡀ᭱኱࡜࡞ࡗ࡚࠸ࡿࡇ࡜ࡀศ࠿ࡿ㸬ࡇࢀࡣ㸪
ᅗ 6 (a)࡟♧ࡍࡼ࠺࡟㸪ᄇᏍෆ㒊ࡢᖹᆒ㍤ᗘࡀ t=0.1 [ms]࡛ᛴ⃭࡟ୗࡀࡗ࡚࠾ࡾ㸪ࡇࡢ᫬ᮇ࡟࢟ࣕࣅࢸ࣮ࢩࣙࣥ
㡿ᇦࡀᄇᏍ඲య࡟ᣑ኱ࡋᄇᏍฟཱྀ࡟㐩ࡍࡿࡵ࡟㸪ᚤ⢏໬⌧㇟ࡀຓ㛗ࡉࢀ㸪ᄇ㟝ゅࡀᣑ኱ࡋࡓࡶࡢ࡜⪃࠼ࡽࢀࡿ㸬90%⵨␃ ᗘ࡜ື⢓ᗘࡢ㧗࠸ Ref. fuel ࡟ࡣࡇࡢࡼ࠺࡞㢧ⴭ࡞ᄇ㟝ゅࡢኚ໬ࡣㄆࡵࡽࢀ࡞࠿ࡗࡓ㸬ᄇᑕᚋ
t=0.4 [ms]௨㝆ࡣ㸪࢟ࣕࣅࢸ࣮ࢩࣙࣥࡢⓎ⏕ࡶᐃᖖ໬ࡋ㸪ᄇ㟝ゅࡣ࡯ࡰ୍ᐃ࡜࡞ࡾ㸪ࡑࡢ್ࡣࣂ࢖࢜⇞ᩱࡀ᭱ࡶ㧗࠸ࡇ࡜ࡀศ࠿ࡿ㸬ᅗ 7(b)ࡣ㸪ᄇᑕᅽຊ Pinj=100 [MPa]ࡢ⤖ᯝ࡛࠶ࡿ㸬ᄇᑕᅽຊࡢ㧗࠸ሙྜࡣ࠸ࡎࢀࡢ⇞ᩱ࡛ࡶᄇᑕᚋࡍࡄ࡟ᄇᏍ඲య࡟࢟ࣕࣅࢸ࣮ࢩࣙࣥࡀⓎ⏕ࡍࡿࡓࡵ㸪ࡉࡽ࡟㏿࠸ẁ㝵࡛ᄇ㟝ゅࡣᐃᖖ≧ែ࡟㐩ࡍࡿ㸬ᐃᖖ≧ែ࡟㐩ࡋ

－ 67 －

(a) Pinj=30 MPa(b) Pinj=100 MPa
ᅗ 5㸬Comparison of internal flow in the nozzle hole at initial stage of injection (Pa =0.1 MPa)㻌
࠸－ 68 －

Dimensionless mean brightness innozzle hole l/lmax [-]Dimensionless mean brightness innozzle hole l/lmax [-]10.80.6

Bio fuelGas oilRef. fuel0.4

1

Bio fuel
Gas oilRef. fuel

0.8

0.6

0.4
00.2

0.4

0.6

0.8

100.2

0.4

Time from start of injection t [ms]

0.6

0.8

10.8

1

Time from start of injection t [ms](b) Pinj=100MPa(a) Pinj=30MPa

25252020

Spray angle ș [deg.]

Spray angle ș [deg.]ᅗ 6㸬Effect of fuel properties on cavitation in the nozzle hole (Pa =0.1 MPa)㻌

1510
Bio fuel
Gas oil

51510
Bio fuel
Gas oil

5Ref. fuelRef. fuel0000.2

0.4

0.6

0.8

1

Time from start of injection t [ms]

00.2

0.4

0.6

Time from start of injection t [ms](b) Pinj=100MPa(a) Pinj=30MPa

ᅗ 7㸬Effect of fuel properties on spray angle (Pa =0.1 MPa)㻌
ࡓᄇ㟝ゅࢆẚ㍑ࡍࡿ࡜㸪90%⵨␃ ᗘ࡜ື⢓ᗘࡢప࠸ࣂ࢖࢜⇞ᩱࡀ㍍Ἔ㸪Ref. fuel ࡜ẚ㍑ࡋ࡚ᄇ㟝ゅࡀ኱ࡁࡃ࡞ࡿഴྥࡀ࠶ࡾ㸪ࡇࢀࡣᅗ 6 (b)ࡢഴྥ࡜୍⮴ࡋ࡚࠸ࡿ㸬 ⇞↝ᐊෆࡢ⇞ᩱᄇ㟝ࡢほᐹ ᄇ㟝ࡢ㧗㏿ࢩࣕࢻ࢘ࢢࣛࣇ᧜ᙳ⿦⨨
ᅗ 8 ࡟ᄇ㟝ྍど໬ᐇ㦂⿦⨨ࡢᴫ␎ࢆ♧ࡍ㸬࢚࢔ࢩࣜࣥࢲ㥑ື࡟ࡼࡾ྾Ẽᘚࢆ㛤ࡅ㸪᤼Ẽᘚࢆ㛢ࡌࡓ≧ែ࡛࢚ࣥࢪࣥࢆ࣮ࣔࢱ㥑ືࡍࡿ㸬࣮ࣟࢱ࣮࢚ࣜࣥࢥ࣮ࢲ࠿
ࡽࡢಙྕࢆᇶ࡟ᅽ⦰⾜⛬๓࡟྾Ẽᘚࢆ㛢ࡌࡿࡇ࡜࡛ᅽ⦰ࡍࡿ㸬㟁Ẽࣄ࣮ࢱ࡟ࡼࡿ྾Ẽຍ⇕(྾Ẽ⟶ෆ ᗘ 400[K])ཬࡧࢩࣜࣥࢲቨ㠃ຍ⇕࡟ࡼࡾᐇᶵࢹ࢕࣮ࢮࣝ㞺ᅖẼࢆᶍᨃࡋࡓ㸬࢚ࣥࢪࣥࡢ࣎࢔ࡣ 78 [mm]㸪ࢫࢺ࣮ࣟࢡ 94 [mm]㸪ᅽ⦰ẚ 17.3㸪ᅇ㌿ᩘ 600 [rpm]࡛࠶ࡿ㸬⇞ᩱᄇᑕ࡟ࡣࢥ࣮ࣔࣥࣞࣝᘧ㟁Ꮚไᚚ⇞ᩱᄇᑕ⿦⨨ࢆ⏝࠸ࡓ㸬ᄇ㟝⵨Ⓨ㐣⛬ࡣࢩࣕࢻ࢘ࢢࣛࣇἲ࡟ࡼࡾほᐹࡋࡓ㸬－ 69 －

ᅗ 8 㸬Experimental apparatus for observation ofevaporation process of sprayᅗ 9㸬Effect of fuel properties on spray behavior－ 70 －

30

Spray tip penetration s [mm]㐃⥆Ⓨ᣺ࡢ Ar+࣮ࣞࢨࢆࢩ࣮ࣗࣜࣞࣥࣞࣥࢬ(f=1,000[mm])࡟ࡼࡾᖹ⾜ග᮰࡟ࡋ㸪ࣆࢫࢺࣥୗ㒊࡟タ⨨ࡋࡓ࣑࣮ࣛࢆ௓ࡋ࡚㸪ࣆࢫࢺࣥ࣊ࢵࢻ࡟タ⨨ࡋࡓࢧࣇ࢓࢖࢔
࢞ࣛࢫ❆ࡼࡾ⟄ෆ࡟ධᑕࡋࡓ㸬ධᑕගࡣ㙾㠃ຍᕤࡋࡓ࢚ࣥࢪࣥ࣊ࢵࢻୗ㠃࡛཯ᑕࡋᢡࡾ㏉ࡋ࡚㸪㧗㏿ᗘ࣓࢝ࣛ࡬ᑟ࠸ࡓ㸬᧜ᙳ㏿ᗘࡣ 20,000 [fps]࡜ࡋࡓ㸬 ᄇ㟝≉ᛶ࡟ཬࡰࡍ⇞ᩱᛶ≧ࡢᙳ㡪 ᅗ 9 ࡟ࡣࢩࣕࢻ࢘ࢢࣛࣇ᧜ᙳ⤖ᯝࢆ♧ࡍ㸬࡞࠾ᄇᑕᅽຊ Pinj=100 [MPa]㸪ᄇᑕ᫬ᮇ ǉinj=-10 [deg.ATDC]㸪
ᄇᑕ㔞 Qinj=13.65 [mg]࡜ࡋࡓሙྜ࡛࠶ࡿ㸬ᅗ 9 ࡼࡾ㸪ࣂ࢖࢜⇞ᩱࡣ-8.92 [deg.ATDC] ௜㏆࡛ᄇ㟝ඛ➃࡟⵨Ẽ㸦ᙳࡢ㍤ᗘࡀቑຍࡋ࡚࠸ࡿ㡿ᇦ㸧ࡀฟ⌧ࡋ㸪ࢩࣜࣥࢲቨ㠃࡟฿㐩ࡍࡿ๓࡟ᄇ㟝ࡣ࡯࡜ࢇ࡝⵨Ⓨࡋ࡚࠸ࡿࡇ࡜ࡀศ࠿ࡿ㸬㍍Ἔࡸ Ref. fuel ࡼࡾ⵨ⓎࡀάⓎ࡛࠶ࡿࡇ࡜ࡀ᫂ࡽ࠿࡛࠶ࡾ㸪ࡇࢀࡣࣂ࢖࢜⇞ᩱࡢ 90%⵨␃ ᗘ࡜ື⢓ᗘࡀప࠸ࡓࡵ࢟ࣕࣅࢸ࣮ࢩࣙࣥⓎ⏕㔞ࡀከࡃ࡞ࡾ㸪ᚤ⢏໬ࡀಁ㐍ࡉࢀࡓࡇ࡜㸪ࡉࡽ࡟㸪ᅗ 1 ࡟♧ࡍࡼ࠺࡟㸪ࣂ࢖࢜⇞ᩱ⮬యࡀ⵨Ⓨᛶࡢ㧗࠸⇞ᩱ࡛࠶ࡿࡇ࡜

N=600 rpm
Pinj=100 MPa
șinj=-10 deg.ATDC
Qinj=13.65 mg

25
20
15

Bio fuel10

Gas oil5

Ref. fuel

00

0.1

0.2

0.3

0.4

0.5

Time from start of injection t [ms]

ᅗ 10㸬Effect of fuel properties on spray tip
penetration࡟ࡼࡾ⵨Ⓨࡀಁ㐍ࡉࢀࡓࡶࡢ࡜⪃࠼ࡽࢀࡿ㸬୍᪉㸪90%⵨␃ ᗘ࡟ᕪ␗ࡀᑡ࡞ࡃ㸪ࣂ࢖࢜⇞ᩱ࡜ẚ㍑ࡋ࡚㸪⵨Ⓨᛶࡢຎࡿ㍍Ἔ࡜ Ref. fuel ࢆẚ㍑ࡍࡿ࡜
⵨Ẽࡀฟ⌧ࡍࡿ᫬ᮇࡣ-8.74 [deg.ATDC]୍࡛⮴ࡋ࡚࠸ࡿࡀ㸪-8.56 [deg.ATDC]࡛ࡣ㸪㍍Ἔࡢ᪉ࡀ⵨Ẽ┦ࡢ㡿ᇦࡀᗈࡃ⵨Ⓨࡀಁ㐍ࡋ࡚࠸ࡿࡇ࡜ࡀศ࠿ࡿ㸬ࡇࢀࡣ㍍
Ἔࡢື⢓ᗘࡀ Ref. fuel ࡼࡾᑠࡉ࠸ࡓࡵ㸪ᚤ⢏໬ࡀಁ㐍ࡋࡓࡓࡵ࡛࠶ࡿ㸬ࡋ࠿ࡋ㸪ᄇ㟝ࡢ࣌ࢿࢺ࣮ࣞࢩࣙࣥ࡟ᑐࡋ࡚⵨Ⓨࡀ㏣࠸௜࠿ࡎ㸪Ref. fuel ྠᵝࢩࣜࣥࢲቨ㠃࡟฿㐩ࡋ㸪ᾮ⭷ࡀᙧᡂࡉࢀࡿࡇ࡜ࡀศ࠿ࡿ㸬 ᅗ 10 ࡟᧜ᙳ⏬ീ࠿ࡽᄇ㟝ඛ➃฿㐩㊥㞳ࢆィ ࡋࡓ⤖ᯝࢆ♧ࡍ㸬ᄇ㟝ඛ➃ࡢ⵨Ⓨ㡿ᇦࢆྵࡵィ ࡋ࡚࠸ࡿࡓࡵ⇞ᩱ࡟ࡼࡾᕪ␗ࡣᑡ࡞࠸ࡀ㸪⇞ᩱࡢ 90%⵨␃ ᗘࡀపࡃ㸪ື⢓ᗘࡀప࠸᪉࠿ࡽ㸪ࣂ࢖࢜⇞ᩱ㸪㍍Ἔ㸪Ref. fuelࡢ㡰࡟ᄇ㟝฿㐩㊥㞳ࡀ㛗ࡃ࡞ࡿഴྥ࡟࠶ࡿࡇ࡜ࡀศ࠿ࡿ㸬ࡇࢀࡽࡣ㸪90%⵨␃ ᗘ࡜ື⢓ᗘࡢపୗ࡟㉳ᅉࡋ࡚㸪࢟ࣕࣅࢸ࣮ࢩࣙࣥⓎ⏕㔞ࡀቑຍࡋ㸪ᚤ⢏໬ࡀಁ㐍ࡉࢀࡿ࡜࠸࠺ᄇᑕࣀࢬࣝෆ㒊ὶືࡢほᐹ⤖ᯝ࡜ࡼࡃ୍
⮴ࡋ࡚࠸ࡿ㸬 ࡲ࡜ࡵ ⇞ᩱᛶ≧ࡢ␗࡞ࡿࣂ࢖࢜⇞ᩱ㸪㍍Ἔ㸪㧗ࢭࢱࣥ౯⇞ᩱࢆ⏝࠸㸪ᄇᏍෆ㒊ὶື࡜ᄇ㟝≉ᛶ࡟ཬࡰࡍ⇞ᩱᛶ≧ࡢᙳ㡪ࢆ⫼ᬒᩓ஘࠾ࡼࡧ㸪ࢩࣕࢻ࢘ࢢࣛࣇ㧗㏿᧜ᙳἲ࡛ㄪ࡭ࡓ⤖ᯝ㸪௨ୗࡢࡇ࡜ࡀ᫂ࡽ࠿࡟࡞ࡗࡓ㸬
 90%⵨␃ ᗘࡀ㧗ࡃ㸪ື⢓ᗘࡀ㧗࠸⇞ᩱ࡯࡝㸪ᄇᏍෆ㒊࡟࢟ࣕࣅࢸ࣮ࢩࣙࣥࡢⓎ⏕ࡀᢚไࡉࢀࡿ㸬
 90%⵨␃ ᗘࡀ㧗ࡃ㸪ື⢓ᗘࡢ㧗࠸⇞ᩱ࡯࡝࢟ࣕࣅࢸ࣮ࢩࣙࣥⓎ⏕ࡀᢚไࡉࢀࡿຠᯝࡣ㸪ᄇᑕᅽຊࡢቑຍ࡟ࡼࡾ┦ᑐⓗ࡟ῶᑡࡍࡿ㸬 ࢟ࣕࣅࢸ࣮ࢩࣙࣥࡢⓎ⏕࡟ࡼࡾ㸪ᄇ㟝ゅࡣቑຍࡍࡿഴྥ࡟࠶ࡿ㸬 ⇞↝ᐊෆ࡛ࡢᄇ㟝ࢆィ ࡋࡓ⤖ᯝ㸪90%⵨␃ ᗘࡀపࡃ㸪ື⢓ᗘࡀప࠸⇞ᩱ࡯࡝㸪ᚤ⢏໬ࡀಁ㐍ࡉࢀ㸪ᄇ㟝ඛ➃㒊ࡢᄇ㟝⵨Ⓨࡀಁ㐍ࡉࢀࡿ㸬ࡇࡢࡇ࡜ࡣ㸪ᄇᑕࣀࢬࣝࡢᄇᏍෆ㒊ὶື࡛ࡢ࢟ࣕࣅࢸ࣮ࢩࣙࣥࡢⓎ⏕ࡀከࡃ࡞ࡿഴྥ࡜㠀ᖖ࡟ࡼࡃ୍⮴ࡍࡿ㸬ཧ⪃ᩥ⊩(1) ΎỈṇ๎㸪᪂஭㞞㝯㸪ᘅᏳ༤அ㸪͆ᾮయᄇὶࡢᚤ⢏໬㐣⛬࡜ࣀࢬࣝෆࡢὶࢀ͇㸪᪥ᮏᶵᲔᏛ఍ㄽᩥ㞟(B⦅)㸪56 ᕳ㸪528 ྕ (1990-8), pp.2519-2525㸬
(2) Chaves,H.,Knapp,M. and Kubitzek,A., “Experimental
Study of Cavitation in the Nozzle Hole of Diesel
Injectors Using Transparent Nozzles”, SAE
Paper, No. 950290 (1995), pp.645-657.
(3) ᯘ᭸༤㸪௚ 3 ྡ㸪͆➼ಸࣔࢹࣝ࡟ࡼࡿࢹ࢕࣮ࢮࣝࣀࢬࣝෆὶࢀ࡜ᄇ㟝⇞↝ࡢྍど໬ゎᯒ͇㸪⮬ື㌴ᢏ⾡఍ㄽᩥ㞟㸪43 ᕳ㸪6 ྕ (2012), pp.1251-1256㸬

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