減圧沸騰噴霧の物理過程と蒸気濃度計測 · Spray and Combustion Science Laboratory, DOSHISHA Univ. 減圧沸騰噴霧の物性過程と蒸気濃度計測減圧沸騰の物性過程

Spray and Comb ustion Science Laboratory, DOSHISHA Univ.

減圧沸騰噴霧の物理過程と蒸気濃度計測

減圧沸騰の物理過程

減圧沸騰噴霧による微粒化・蒸発過程の改善

減圧沸騰噴霧の微粒化・蒸発過程のモデリング減圧沸騰噴霧の微粒化・蒸発過程のモデリング

ガス溶解燃料噴霧の微粒化過程

二成分・他成分燃料噴霧への減圧沸騰現象の適用

解析モデル

KIVAコードへの減圧沸騰噴霧モデルの適用

赤外域２波長濃度測定法Spray and Combustion Science Laboratory, DOSHISHA Univ.

減圧沸騰噴霧の物理過程と蒸気濃度計測

同志社大学　工学部

千田　二郎

Spray and Combustion Science Laboratory, DOSHISHA Univ.

減圧沸騰噴霧の物性過程と蒸気濃度計測

減圧沸騰の物理過程減圧沸騰の物理過程


減圧沸騰噴霧の微粒化・蒸発過程のモデリング



解析モデル


赤外域２波長濃度測定法Spray and Comb ustio n Science Laboratory, DOSHISHA Univ.

減圧沸騰による相変化


気泡の核生成過程

Spray and Comb ustio n Science Laboratory, DOSHISHA Univ.

Rayleigh-Plessetの式

232

wP PR R Rρ

∞−⋅ + =

2

2,dR d RR Rdt dt

≡ =

液体の粘性と圧縮性を無視した場合の気泡の運動方程式

ただし

wP 気泡壁の圧力

P∞ 無限遠の流体圧力

ρ 流体密度


気泡の安定性

( ) 3

2w

w

f P P

kP P

R Rσ

∞

∞

= −

= − − − +


Flash Boiling Injection Process


Spray Measurement of Flash Boiling Spray

Mie scattering imagefrom droplets

Spatial vapor concentration distributionby two-wave length IR absorption method

n-Pentane S pray(Pv=56.5KPa) injected into 21KPa ambient pressure


Analytical model of flash boiling spray in this study

Vapor formation process

1

l b

d

Nucleation process

Bubble growth process

Droplet formation process

(1) By cavitation bubbles growth

( )3 31

43cb v n ndM N R Rπ += −ρ

(3) By superheated degree

( )l st

fg

sh

sh

T T A dt

hdM

′′ − ⋅=α

Droplet number = 2×Bubble number

bubble

bubble liquid

VV V

ε ε= ≥+ max

( )22 13 W rR P P

rRR = −+

30

0

20

n

W V rRP P P

R Rσ = + +

12

2 4 4R RR R Rσ µ κ

− − − −

and

Initial bubble diameter 2R0

2R0=20mm

( )120=1.11×10 exp -5.28N T∆

( ){ }-4.34exp -510 t×

( )a f

fg

ht

ht

T T A dt

hdM

′− ⋅=α

(2) Owing to heat transfer

Modeling of Flash Boiling Spray


噴霧の微粒化と蒸発の時空間特性

圧力噴射弁（高圧噴射）の場合　　⇒ Pinj , ρa , Ta

①微粒化遅れ tb（時間・空間）

tb

Pinj

βα PrRe ⋅⋅= cNu②液滴の蒸発時間（時間・空間）

tATq ⋅⋅∆⋅= αT

Tsat

t

q T A tα= ⋅∆ ⋅ ⋅

2Nu =Re PrNu c α β= ⋅ ⋅028.65( )l

b

a in j a

dt

P P

ρρ

⋅=

⋅ −

③噴霧の蒸発長さ（時間・空間）

Pinj

Lev

2f f fm d Uρ∝ ⋅ ⋅

tan( /2)a a f fm d x Uρ ρ θ∝ ⋅ ⋅ ⋅ ⋅ ⋅

SMD

飽和領域

Pinj

2P

R

σ ∆ =

① ③Nozzleinternal flow

Turbulence flow ②

リップル⇒ リガメント⇒液滴

Cavity


噴霧の微粒化と蒸発の時空間特性減圧沸騰噴霧の場合⇒二相領域Profile, ∆Pbv(∆θ), ノズル形状

bubble ligament

dropintact core

※ 減圧沸騰は液体内部からの蒸気泡発生による内部沸騰蒸発（潜熱は必要）

空気せん断力（Aerodynamic Force）不要流体自身のエンタルピバランスで蒸発

発泡気泡核数→核生成速度

蒸発速度→気泡の成長速度

expA

N Ck θ∆ ∝ ⋅ − ∆

24

3A Rπ σ∆ = ⋅

Rayleigh-Plesset式 23 1( )

2w r

R R R P Pρ

+ = −

n

bvR P∝ ∆

Vapor mass

f raction

t

1.0

数msのオーダー

tb

∆Pbv

200 µs

100 µs

R

tµs

気泡成長に伴う，ボイド率律則による液膜・液流の崩壊

∆Pbv

∆θ

P

T

多成分燃料

∆Pbv

∆θT

P単成分燃料



減圧沸騰の物性過程

減圧沸騰噴霧による微粒化・蒸発過程の改善減圧沸騰噴霧による微粒化・蒸発過程の改善




解析モデル



実験装置および方法

Densityρ1　[kg/m3]

Surface　Tensionσ×10-3 [N/m]

Viscosityµ×10-6 [Pa･s]

Saturated Vapor PressurePv [kPa]

n-Pentane n-Hexane

626 656

16.00 18.46

240 307

56.5 16.2

Densityρ1　[kg/m3]

Surface　Tensionσ×10-3 [N/m]

Viscosityµ×10-6 [Pa･s]

Saturated Vapor PressurePv [kPa]

n-Pentane n-Hexane

626 656

16.00 18.46

240 307

56.5 16.2

Spray and Combustion Science Laboratory, DOSHISHA Univ.n-Hexane

n-Pentane

n-Hexanen-Hexane

n-Pentane

噴霧形状の背圧による変化

Spray and Combustion Science Laboratory, DOSHISHA Univ. Spray and Comb ustio n Science Laboratory, DOSHISHA Univ.

噴霧特性の差圧による変化

Injection quantityQinj. [mm3/4ms]

Flow velocity at section AVA [m/s]

Jet velocity at nozzleOutlet Vinj. [m/s]

Reynolds number atsection A Re

n-Pentane n-Hexane

13.2 13.6

18.3 18.8

21.0 21.0

6500 5400

Injection quantityQinj. [mm3/4ms]

Flow velocity at section AVA [m/s]

Jet velocity at nozzleOutlet Vinj. [m/s]

Reynolds number atsection A Re

n-Pentane n-Hexane

13.2 13.6

18.3 18.8

21.0 21.0

6500 5400


噴孔部拡大写真


噴射弁内部の燃料流動の模式図





減圧沸騰噴霧の微粒化・蒸発過程のモデリング減圧沸騰噴霧の微粒化・蒸発過程のモデリング



解析モデル



核生成モデルと臨界気泡径


減圧沸騰噴霧における気泡核生成


減圧沸騰噴霧における蒸発過程

(a) 熱伝達による蒸発過程 (b) 加熱度に起因する蒸発過程


液膜分裂モデルと減圧沸騰モデル


減圧沸騰モデルの計算結果

気泡径・液滴径・質量蒸発割合の時間変化 (n-ペンタン)

各質量蒸発割合の時間変化（n-ペンタン，Pb=14kPa)



噴霧外形の比較(n-ペンタン) 液滴径の比較



蒸気質量の時系列変化






ガス溶解燃料噴霧の微粒化過程ガス溶解燃料噴霧の微粒化過程


解析モデル




Solubility limit of gas for n-Tridecane Change in spray width







二成分・他成分燃料噴霧への減圧沸騰現象の適用二成分・他成分燃料噴霧への減圧沸騰現象の適用

解析モデル



0.10.2

0.40.5

0.6

0.70.8

0.9

0.95

1.0

0.0

0.99

0.3Conditionsat injectionto cylinder

Ambientconditions in Diesel Engine

Mole fractionof CO2 : XCO2

Conditionsinside nozzle

100 200 300 400 500 600 700 800Fuel temperature Tf [K]

0

10

20

30

Fuel

pre

ssur

e pf[M

Pa]

Two-Component Solution[CO2 – n-Tridecane]

Pure Substance

0

5

10

15

20

25

Temperature [K]

NH3

CO2

N2

Pres

sure

[M

Pa]

Methane

Tridecane

Condition inside the nozzle

0 200 400 600 800

H2O

Condition inthe cylinder

Pentane

Methanol

Phase Change Process in P-T Diagram


Two Phase Region Formation in Multi-componentFuel in Phase Change Process

Temperature

Pres

sure

Saturat

ed

vapor

line

Saturat

ed

liquid

line

Critical pressureCritical point

Liquid phase region

Vapor phase region0

pc

TcCritical temperature

Two p

hase

regio

n

Low VaporPressure

ComponentMixed in

High VaporPressure

Component

Pressure-temperature diagram Pressure-Mole fraction diagram

Pres

sure

[kPa

]

0 0.25 0.5 0.75 1

Liquid

Vapor

Vapor mole fractionof high vapor pressure

Vapor mole fractionof low vapor pressure

Tw o phaseregion

LiquidVapor

Mole fraction


液体相互溶解と臨界軌跡液体相互溶解と臨界軌跡

Mutual solubility in binary solution Effect of mole fraction on two Phase regionfor n-Tridecane-CO2


Chemical Thermodynamics and Two-Phase Region

0.10.2

0.40.5

0.6

0.70.8

0.9

0.95

1.0

0.0

0.99

0.3Conditionsat injectionto cylinder

Ambientconditions in Diesel Engine

Mole fractionof CO2 : XCO2

Conditionsinside nozzle

100 200 300 400 500 600 700 800Fuel temperature Tf [K]

0

10

20

30

Fuel

pre

ssur

e p f

[MPa

]

P -T Diagram for Mixing Fue l withLiquefie d CO2 & n-tridecane

Es timation of Two-Phas e Region

Expanded CorrespondingState Principle

/r CP P P= /r CT T T=,Peng-RobinsonEquation of States

{ }( )

( ) ( )RT a TP

V b V V b b V b= −

− + + −

Fugacity of Liquid & Gas

/( )G Gi i if y Pφ = ⋅ /( )L L

i i if X Pφ = ⋅,

G Li if f=

The prediction of Two-Phase RegionSpray and Comb ustio n Science Laboratory, DOSHISHA Univ.

液化液化COCO22溶解燃料噴霧の噴霧特性溶解燃料噴霧の噴霧特性

Injection system of gas dissolved fuel


準定常噴霧の分散特性準定常噴霧の分散特性

Change in spray pattern with CO2 volume fraction for quasi-steady spray



Change in spray pattern with ambient pressure and mole fraction of CO2 by transmitted light for quansi-steady s pray(pinj=10[MPa],ra=1.5[kg/m3])


Change in spray cone angle for quasi-steady s pray




非定常噴霧の噴霧構造と微粒化特性非定常噴霧の噴霧構造と微粒化特性

Temporal change in s pray tip pattern by shadowgraph method for unsteady s pray

Spray and Comb ustio n Science Laboratory, DOSHISHA Univ.Droplet size distribution for unsteady spray(t=6[ms])

非定常噴霧の噴霧構造と微粒化特性非定常噴霧の噴霧構造と微粒化特性


減圧沸騰噴霧の特性を解析噴霧を科学する

混合燃料による二相領域の形成と噴霧蒸発過程の制御

（多成分燃料の蒸発解析）

①液化CO2-軽油混合燃料噴霧による　すす-NOX同時低減

②ガス・ガソリン-軽油混合燃料噴霧による燃焼過程の制御の可能性

今後の研究課題として　（参考）

① Sono-Chemistryによる燃料の改質

②固体燃料・重質系燃料の高品位液体燃料への改質

燃料設計手法による高効率・低エミッション燃焼法の提案研究


Proposal on Fuel Design Approach Research

Spray and Combustion Science Laboratory, Doshisha University

(1) Physical Control = Capability of Time and S patial Control on Fuel Vapor Distribution by Formation of Two Phase region in Mixing Fuel

Formation of Flash Boiling Spray Improvement of Spray Evaporation

(2) Chemical Control = Capability of Control on Combustion ProcessEmission Control – Soot & NOxSimultaneous reduction of both Soot and NOx (CO2-gas oil mixing fuel)Ignition Control (Gasoline-gas oil mixing fuel)HC Control (Gasoline-gas oil mixing fuel)

(3) Improving Thermal Efficiency by Lower Injection PressureHigh S pray Atomization and Evaporation Quality with Flashing Process

(4) Control the Fuel Trans portation Properties in Mixing Fuels

(5) Effective liquefaction of gaseous and solid fuelsConversion of Heavy Fuels or Solid Fuels into high qualityLighter Liquid Fuels through Chemical-Thermodynamics








解析モデル解析モデル



Distillation Analysis for Multi-component Fuel

Boiling point [K]

Dis tillation Curve10-components Fuel

300 350 400 450Distillation temperature [K]

0.0

0.2

0.4

0.6

0.8

1.0

Dis

tilla

tion

ratio

[-]

Component Boiling Point [K]

Molarfraction

0.04(a)n-butane 272.6

0.35(b)isopentane 301.00.12(c)2-methylpentane 333.40.06(d)cyclohexane 353.9

0.12(e)2,2,4-trimethylpentane

372.4

0.06(f)toluene 383.80.06(g)meta-xylene 412.3

0.06(h)ortho-xylene 417.60.06(i)propylbenzene 432.4

0.06(j)butylbenzene 456.5


Time Dependence of Evaporation Analysis for10-Components Fuel Single Drop

0.0 2.0 4.0 6.0 8.0 10.0Time [ms]

300

360

420

480

Dro

plet

tem

pera

ture

[K]

0.00.2

0.4

0.6

0.8

1.0

Evap

orat

ion

ratio

[-]

0.0 2.0 4.0 6.0 8.0 10.0Time [ms]

0.0 2.0 4.0 6.0 8.0 10.0Time [ms]

0

250

500

750

1000

Squa

re o

f dro

plet

dia

met

erd2

[µm

2 ]

Ta = 400 [K]Ta = 480 [K]Ta = 800 [K]

Pa = 0.5 [MPa]r0 = 15 [µm]


Comparison of Spray Structure –Vapor Spatial Distribution–

with Experiments and Numerical Results at t=3.0ms0

20406080

1000

20406080

1000

20406080

100

Axi

al d

ista

nce

from

noz

zle

tip [m

m]

XC5H12 = 0.25

XC5H12 = 0.50

XC5H12 = 0.75

7.44e-46.69e-45.95e-45.21e-44.46e-43.72e-42.98e-42.23e-41.49e-47.44e-50.00

VaporC5

[g/cm3]6.99e-46.29e-45.60e-44.90e-44.20e-43.50e-42.80e-42.10e-41.40e-46.99e-50.00

VaporC13

[g/cm3]

Intensity of LIFHigh

High

Low

Low

C13

C5

le ft : LIF im a geMiddle : ca lcula tion

(n-pe ntane )right : ca lcula tion

(n-tride cane )C5 C13

LIF Calculation


Fig.37 Analytical model of flash boiling spray in this study

・・・(b)

・・・(c)

・・・(a)

Fig.37 Analytical model of flash boiling spray in this study

・・・(b)

・・・(c)

・・・(a)

解析モデル解析モデル


減圧沸騰における減圧度に依存する気泡成長過程減圧沸騰における減圧度に依存する気泡成長過程

Change in bubble growth with ambientpressure　 (Xco2=0.6，Tf=383[K])

Change in bubble growth with ambient Pressure　 (Xco2=0.8，Tf=383[K])


減圧沸騰における燃料蒸気濃度減圧沸騰における燃料蒸気濃度

Temporal change in vapor mass　 (Xco2=0.6，Tf=383[K]) Spray and Comb ustio n Science Laboratory, DOSHISHA Univ.

減圧沸騰における燃料蒸気濃度減圧沸騰における燃料蒸気濃度

Temporal change in vapor mass　 (Xco2=0.8，Tf=383[K])








解析モデル

KIVAKIVAコードへの減圧沸騰噴霧モデルの適用コードへの減圧沸騰噴霧モデルの適用


Flash-Boiling Spray Model

Initial fuel properties

NIST database (f(T, P))

Vaporization

Flash-boiling in dropletVaporization on droplet surface

Flash-boiling in nozzle orificeBubble nucleation (heterogeneous nucleation)

Bubble growth (Rayleigh-Plesset equation)

①

①Fuel injection

Injection of multicomponent fuel dropletswith bubbles

②

②Breakup

Modified TAB model (φ=6) ③


Flash-Boiling Spray Model (continued)

Flash-boiling in droplet ②Bubble nucleation (heterogeneous nucleation)Bubble growth (Rayleigh-Plesset equation)Bubble disruption (ε > 0.55)

Renewal of fuel propertiesNIST database (f(T, P))

⇒ Secondary breakup ③

①

Vapor-liquid equilibrium (fugacity)Vaporization on droplet surface ④

Renewal of fuel propertiesModified Spalding model (Le≠1)Two-zone model (Tds, Tdi,)

NIST database (f(T, P))④

②

③


liquidbubble

bubble

VVV

+=εBubble disruption

droplets=bubbles*2

Nozzle orifice Droplet

Bubble nucleation

{ })5exp(34.412 1028.5exp1011.1 tN ⋅−−

∆−

⋅×=θ

Bubble nucleation

{ })5exp(34.412 1028.5exp1011.1 tN ⋅−−

∆−

⋅×=θ

2

30

00

4422R

RR

RRR

RR

PPP ln

rvwκµσσ

−−−

++=

( )rw PPRRR −=+ρ1

23 2

Bubble growth

2

30

00

4422R

RR

RRR

RR

PPP ln

rvwκµσσ

−−−

++=


23 2

Bubble growth

liquidbubble

bubble

VVV


droplets=bubbles*2liquidbubble

bubble

VVV


droplets=bubbles*2

Nozzle orifice Droplet

Bubble nucleation

{ })5exp(34.412 1028.5exp1011.1 tN ⋅−−

∆−

⋅×=θ

Bubble nucleation

{ })5exp(34.412 1028.5exp1011.1 tN ⋅−−

∆−

⋅×=θ

Bubble nucleation

{ })5exp(34.412 1028.5exp1011.1 tN ⋅−−

∆−

⋅×=θ

Bubble nucleation

{ })5exp(34.412 1028.5exp1011.1 tN ⋅−−

∆−

⋅×=θ

2

30

00

4422R

RR

RRR

RR

PPP ln

rvwκµσσ

−−−

++=


23 2

Bubble growth

2

30

00

4422R

RR

RRR

RR

PPP ln

rvwκµσσ

−−−

++=


23 2

Bubble growth

2

30

00

4422R

RR

RRR

RR

PPP ln

rvwκµσσ

−−−

++=


23 2

Bubble growth

2

30

00

4422R

RR

RRR

RR

PPP ln

rvwκµσσ

−−−

++=


23 2

Bubble growth

減圧沸騰噴霧モデル減圧沸騰噴霧モデル

Schematic diagram of flash-boiling model


LiquidBubble

Droplets =Bubbles×2

ε < εmax ε = εmax

Bubble growth BreakupLiquid

Bubble

Droplets =Bubbles×2

ε < εmax ε = εmax

Bubble growth Breakup

気泡崩壊気泡崩壊

Breakup caused by bubble disruption


1: Oil pump 2: Thermo-couple 3: Pressure gauge

4: Injection nozzle 5: Thermo-couple 6: Heating jacket

7: Optical window 8: Heater 9: Insulator

300V

300V

Gas in

Gas out

t° t°

t°

N2

1

3

2

4

7

9

5

6

8







300V

300V

Gas in

Gas out

t° t°

t°

N2

1

3

2

4

7

9

5

6

8

300V

300V

Gas in

Gas out

t°t° t°t°

t°t°

N2

1

3

2

4

7

9

5

6

8

実験および計算方法と設定条件実験および計算方法と設定条件

Schematic diagram of constant volume vessel


Ambient gas N2

Ambient pressure 0.1 MPaAmbient temperature 440 KHole diameter 0.2 mmInjection pressure 15.0 MPaInitial fuel temperature 320, 380, 440 K

C5H12 / C13H28

0.75 : 0.25 (mol %)Fuel

Ambient gas N2

Ambient pressure 0.1 MPaAmbient temperature 440 KHole diameter 0.2 mmInjection pressure 15.0 MPaInitial fuel temperature 320, 380, 440 K

C5H12 / C13H28

0.75 : 0.25 (mol %)Fuel


Experimental conditions


Comparison of Spray Structure –Vapor Spatial Distribution–

with Experiments and Numerical Results at t=3.0ms0

20406080

1000

20406080

1000

20406080

100

Axi

al d

ista

nce

from

noz

zle

tip [m

m]

XC5H12 = 0.25

XC5H12 = 0.50

XC5H12 = 0.75

7.44e-46.69e-45.95e-45.21e-44.46e-43.72e-42.98e-42.23e-41.49e-47.44e-50.00

VaporC5

[g/cm3]6.99e-46.29e-45.60e-44.90e-44.20e-43.50e-42.80e-42.10e-41.40e-46.99e-50.00

VaporC13

[g/cm3]

Intensity of LIFHigh

High

Low

Low

C13

C5

le ft : LIF im a geMiddle : ca lcula tion

(n-pe ntane )right : ca lcula tion

(n-tride cane )C5 C13

LIF Calculation


250 300 350 400 450 500Temperature [K]

Pres

sure

[MPa

]

0.0

0.2

0.4

0.1

0.3

0.5

C5C13

C5/C13

Ambient condition

Two-phase region

320K 380K 440K

250 300 350 400 450 500Temperature [K]

Pres

sure

[MPa

]

0.0

0.2

0.4

0.1

0.3

0.5

C5C13

C5/C13

Ambient condition

Two-phase region

320K 380K 440K


Initial fuel temperature variations Spray and Comb ustio n Science Laboratory, DOSHISHA Univ.

Droplet and Vapor Distributions

Tf=320 K Tf=380 K Tf=440 K

20

40

60

80

100

0

Dis

tanc

e fro

m n

ozzle

[mm

]

Exp. C5 C13

Low High

Vapor concentration

tinj=1.0 ms


Enlarged Shadowgraph Images

5

10

15

20

0

Dis

tanc

e fro

m n

ozzl

e [m

m] Tf=320K Tf=440K

0.3 0.5 1.8

Time from start of fuel injection [ms]

0.3 0.5 1.8


0

20

40

60

80

100

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4Time after start of fuel injection [ms]

Fuel

pen

etra

tion

[mm

]

Wall-impingingTf=320K (KIVA)Tf=380K (KIVA)Tf=440K (KIVA)Tf=320K (Exp.)Tf=380K (Exp.)Tf=440K (Exp.)

0

20

40

60

80

100


Fuel

pen

etra

tion

[mm

]

Wall-impingingTf=320K (KIVA)Tf=380K (KIVA)Tf=440K (KIVA)Tf=320K (Exp.)Tf=380K (Exp.)Tf=440K (Exp.)

Tf=320K (KIVA)Tf=380K (KIVA)Tf=440K (KIVA)Tf=320K (Exp.)Tf=380K (Exp.)Tf=440K (Exp.)

Tf=320K (KIVA)Tf=380K (KIVA)Tf=440K (KIVA)Tf=320K (Exp.)Tf=380K (Exp.)Tf=440K (Exp.)

噴霧先端到達距離噴霧先端到達距離

Fuel penetration


0.0

0.4

0.8

1.2

1.6

2.0

2.4


Vap

or m

ass

of n

-pen

tane

[mg]

Injected C5Tf=320KTf=380KTf=440K

Wall-impinging0.0

0.4

0.8

1.2

1.6

2.0

2.4


Vap

or m

ass

of n

-pen

tane

[mg]



Wall-impinging

Vapor mass of n-pentane

蒸気量蒸気量


0.0

0.4

0.8

1.2

1.6

2.0

2.4


Vap

or m

ass

of n

-trid

ecan

e[m

g]


Wall-impinging0.0

0.4

0.8

1.2

1.6

2.0

2.4


Vap

or m

ass

of n

-trid

ecan

e[m

g]



Wall-impinging

蒸気量蒸気量

Vapor mass of n-tridecane


0.00.10.20.30.40.50.60.70.8

10 20 30 40 50 60 70 80 90 100Droplet diameter [µm]

Freq

uenc

y

Tf=320KTf=380KTf=440K

0.00.10.20.30.40.50.60.70.8

10 20 30 40 50 60 70 80 90 100Droplet diameter [µm]

Freq

uenc

y




液滴粒径分布と平均粒径液滴粒径分布と平均粒径

Droplet diameter distribution (tinj=0.5 ms)


0

20

40

60

80

100

120


Sau

ter m

ean

diam

eter

[µm

]


Wall-impinging

0

20

40

60

80

100

120


Sau

ter m

ean

diam

eter

[µm

]




Wall-impinging

Sauter mean diameter

液滴粒径分布と平均粒径液滴粒径分布と平均粒径








解析モデル



光計測法の分類　　　　　　　　　　　　　　　　＊吸収法ーーLambert-Beer則＜濃度計測＞　　　　　　　　　モル吸光係数＝Ｆ（温度・圧力・濃度）

＊発光法ーー・自発光（ＯＨ，ＣＨ,etc）　　　　　　　　　　　　強度＝Ｆ（濃度・温度）　　　　　　　　　・強制発光（ＬＩＦなど）　　　　　　　　　　　　強度＝Ｆ（量子収率）


LscLabVab I

III

II

II )log()log()log()log( 00

14500

14500 ++=

赤外域赤外域22波長濃度測定法波長濃度測定法

Schematic diagram of IRES theory Spray and Comb ustio n Science Laboratory, DOSHISHA Univ.

赤外域赤外域22波長濃度測定法波長濃度測定法

Absorption s pectrum of n-pentane vapor (593 ppm)


実験装置，方法および実験条件実験装置，方法および実験条件

Schematic diagram of experimental apparatus for measurement of vapor concentration distribution


検定結果検定結果

Relation between absorbance and optical length

Spray and Combustion Science Laboratory, DOSHISHA Univ.Spray and Combustion Science Laboratory, DOSHISHA Univ.

燃料蒸気濃度分布燃料蒸気濃度分布

Concentration distribution of n-pentane vapor(Pa=48kPa, t=2.0ms,DP=250kPa,Tf=Ta=293K)


燃料蒸気濃度分布燃料蒸気濃度分布

Concentration distribution of n-pentane vapor(Pa=14kPa, t=2.0 ms,DP=250kPa,Tf=Ta=293K)


Spray Measurement of Flash Boiling Spray

Mie scattering imagefrom droplets

Spatial vapor concentration distributionby two-wave length IR absorption method

n-Pentane S pray(Pv=56.5KPa) injected into 21KPa ambient pressure

Spray and Comb ustio n Science Laboratory, DOSHISHA Univ.Doshisha Univ. Spray & Combustion Lab

Exciplex蛍光法による壁面衝突噴霧の解析


The Absorption and the Transition Process of the Light

S1

S0

R1 R2

S1

T1 T1

(5)RT∆E

(3)

(7)

(1) (8) (2) (7) (4) (9) (6)

ICKq

Kf

τ f

KDF

τ DF

KP

τ P

ISCKq

T

Kisc

K’isc

S0 : Ground singlet stateS1 : Singlet excited stateT1 : Triplet excited stateR : Vibrational transitionIC : Internal conversion

ISC : Intersystem crossingk : Rate constant of transition

τ : Radiative lifetime


The Quenching Action of the Fluorescence

1) the Static Quenching

2) the Dynamic Quenching,

h : Planck’s Constant = 6.626×10-34 [j・s]v : the frequency of the fluorescence [s-1]

The Quenching by the Molecule

,M N MN MN hv+ ⇔ + → energy loss

1 *M hv M+ →

PositiveNegativeTemperature coeff icient of quenchingConstantVariableAbsorption spectrumVariableConstantFluorescence polarizingVariableConstantFluorescence lifetimeDynamic quenchingStatic quenching

Table. Characteristics of the static and dynamic quenching

(a) the Thermal Quenching(b) the Concentration Quenching : (c) the Quenching by Oxygen :

The General Quenching Phenomenon

( )1 *1 *M M M M+ ⇔ ⋅( )*1 * 3 *

2 2 2M O M O M O+ → ⋅ → +

1 *M N M N+ → +


Exciplex Fluorescence Method

1M* : monomer vaporN : quencher

1(M・N)* : exciplex liquid

( )1 *1 *M N M N+ ⇔ ⋅

Schematic Summery of Photophysics for Np/TMPD Exciplex System

Naphthalene (as N)

N,N,N’,N’-tetramethyl-p-phenylene-diamine(as M)

NN CH3CH3

CH3CH3

Np*+TMPD Np+TMPD*

[ Np/TMPD ]*

Np+TMPD

340nm 390nm480nm

Spray and Comb ustio n Science Laboratory, DOSHISHA Univ.Doshisha Univ. Spray & Combustion Lab

1.1

1.0

0.9

0.8

0.7550 600 650 700

Rel

ativ

e flu

ores

cenc

e in

tens

ity

I(Ta)

/I(60

0)

Ambient temperature Ta [K]

Change in Relative Vapor Fluorescence Intensity with Ambient Temperature

ρa = 12.3 kg/m3

800750

The Change of the Vapor Fluorescence Intensity caused by the Ambient Temperature and Vapor Concentration


Fluorescent Substance

Absorbed LightIaTransmitted Light

It

Incident Laser LightI0 [J/(m2・s)]

L [m]

Impinging Spray

I0

L Ii12ii+1 I0

Emission Intensity Fi

Wall

Mole ConcentrationC [mol/m3]

Model on Vapor Concentration Analysis with Light Absorption

(a) Analysis model (b) Calculation mesh in impinging spray

0 exp( )tI I CLε= −

( ){ }0 0 1 expa tI I I I CLε= − = − −

( )0 1expi iI I L Cε −= − ∑( ) ( ){ }0 1exp 1 expi i iF A K I L C C Lε ε−= ⋅ ⋅ − − −∑

The Calculation of Vapor Concentration by Lambert-Beer Low(3-1)

(3-2)

(3-3)

(3-4)

ε : molar absorptivity [m3/mol・m]C : concentration of fluorescence

material [mol/m3]

A : constant of optical apparatusK : probability of luminous transition

Quantification of the Vapor Concentration – 1


Quantification of the Vapor Concentration – 2Change in Relative Vapor Fluorescence

Intensity with Fuel Vapor Concentration Concentration Quenching

0.0 1.0 2.0 3.0 4.0 6.05.0 7.00.0

1.0

2.0

3.0

4.0

5.0

6.0

Vapor concentration C/Cmi n

Fluo

resc

ence

inte

nsity

ratio

F/

F min

ExperimentalTheoreticalEq.3-4

0.0 0.0250.0500.0750.1000.1250.5

0.6

0.7

0.8

0.9

1.0

1.1

Que

nchi

ng c

oeffi

cient

Kc

TMPD concentration C [mol/m3]

( ) ( ){ }0 1exp 1 expi C i iF A K K I L C C Lε ε−= ⋅ ⋅ − − −∑Eq.3-4 (3-5)

Ta = 700 KPa = 2.5 MPa

Ta = 700 KPa = 2.5 MPa

Spray and Combustion Science Laboratory, DOSHISHA Univ.Doshisha Univ. Spray & Combustion Lab

The Correction of the Vapor Concentrationwith Mixture Temperature

Mixture Mean Temperature

Relation Between Temperature and Relative Fluorescence Intensity

( ){ }0v fl sat l f a a ent v fv satr

v fv a a

C c T T h c T C c TT

C c cρ

ρ− − + + +

=+

(3-6)

Cv : concentrat ion of the fuel vapor [kg/m3] , ρa : density of the ambient gas [kg/m3]c : specific heat [J/(kg・K)] , hf : latent heat of vaporization [J/kg]

Tsat : saturation temperature of the fuel [K] , Tl0 : initial temperature of the fuel [K]Tent : temperature of the entrainment ambient gas [K]

( )( ) ( )

0

exprqa qb r

F TK K T

F T= − (3-7)

Kqa , Kqb : coefficient of temperature quenching


Thermocouple

Fan

Flatwall

Rupturedisk

Pressuregauge

InjectionnozzleCoolingjacket

OpticalwindowHeater

Pressurebomb

Oilpump

Insulator

High Temperature and Pressure Constant Volume Chamber

The Schematic Diagram of the Experimental Apparatus

Spray and Combustion Science Laboratory, DOSHISHA Univ.Doshisha Univ. Spray & Combustion Lab

The Schematic Diagram of Laser Sheet Optical System and Photography System

Cylindrical lens

Dichroic mirror

Band Pass Filter

CCD camera

Image analyzer

Nd:YAG laser

Object lens

Image intensifier

Relay lens


Injectionnozzle

Type : Hole nozzle DLL-p

Diameter of hole

Length of hole

dn [mm]

Ln [mm]

0.2

1.0

Ambient gas

Ambient temperature

Ambient pressure

Ambient density

Temperature of wall surface

Injection pressure

Injection quantity

Injection duration

Impingement distance

N2 gas

Ta

pa

ρa

Tw

pinj

Qinj

tinj

Zw

[K]

[MPa]

[kg/m3]

[K]

[MPa]

[mg]

[ms]

[mm]

700

1.04, 1.70, 2.55

5.0, 8.2, 12.3

550, 600, 650

22, 42, 72, 112

12.0

2.82, 1.98, 1.54, 1.20

24, 30, 34, 40

The Experimental Condition

† Standard condition† Parameter


The Analysis Process in Every Parameter

Unimpingingregion

Impi

ngin

g di

stan

ce

Z w

Main jet region

Wall spray

Spray radius ofliquid phase Rw

Spray radius of v apor phase RwR

Leading edge

h

Spr

ay h

eigh

th w

Model on Vaporizing Impinging Diesel Spray

The impinging spray image(a) Vapor concentration(b) Mixture temperature(c) Liquid fluorescence intensity

The spray radius & height

The relative fuel vapor volume

Radial distribution of fuel vapor


Spr

ay h

eigh

th w

[mm

]

Spray radius Rw [mm]

15

10

5

00 5 10 15 20 25 30

t = 0.4 ms

0 5 10 15 20 25 30

t = 0.8 ms

Spr

ay h

eigh

th w

[mm

]


15

10

5

00 5 10 15 20 25 30

t = 0.4 ms

0 5 10 15 20 25 30

t = 1.2 ms

0 5 10 15 20 25 30

t = 1.6 ms

10

Spr

ay h

eigh

th w

[mm

]


15

5

00 5 10 15 20 25 30

t = 0.4 ms

0 5 10 15 20 25 30

t = 0.8 ms

0 5 10 15 20 25 30

t = 1.2 ms

0 5 10 15 20 25 30

t = 1.6 ms

0 5 10 15 20 25 30

t = 0.8 ms

0 5 10 15 20 25 30

t = 1.2 ms

0 5 10 15 20 25 30

t = 1.6 ms

8.9, λ = 0.57.5, λ = 0.66.1, λ = 0.74.6, λ = 0.93.2, λ = 1.41.8, λ = 2.50.4, λ = 12

[mol/m3]

700675650625600575550[K]

High

Low

Fluorescenceintensity

(a) Vapor concentration

(b) Mixture temperature

(c) Liquid f luorescence intensity

Temporal Change in the Impinging S pray Image with Exciplex Fluorescence Method- Pinj=120[MPa], Qinj=12.0[mg], Tw=550[K], ρ a=12.3[kg/m3], Zw=24[mm] -


Spr

ay h

eigh

th w

[mm

]


15

10

5

00 5 10 15 20 25 30

t = 0.4 ms

0 5 10 15 20 25 30

t = 0.8 ms

Spr

ay h

eigh

th w

[mm

]


15

10

5

00 5 10 15 20 25 30

t = 0.4 ms

0 5 10 15 20 25 30

t = 1.2 ms

0 5 10 15 20 25 30

t = 1.6 ms

10

Spr

ay h

eigh

th w

[mm

]


15

5

00 5 10 15 20 25 30

t = 0.4 ms

0 5 10 15 20 25 30

t = 0.8 ms

0 5 10 15 20 25 30

t = 1.2 ms

0 5 10 15 20 25 30

t = 1.6 ms

0 5 10 15 20 25 30

t = 0.8 ms

0 5 10 15 20 25 30

t = 1.2 ms

0 5 10 15 20 25 30

t = 1.6 ms

8.9, λ = 0.57.5, λ = 0.66.1, λ = 0.74.6, λ = 0.93.2, λ = 1.41.8, λ = 2.50.4, λ = 12

[mol/m3]

700675650625600575550[K]

High

Low







Spr

ay h

eigh

th w

[mm

]


15

10

5

00 5 10 15 20 25 30

t = 0.4 ms

0 5 10 15 20 25 30

t = 0.8 ms

Spr

ay h

eigh

th w

[mm

]


15

10

5

00 5 10 15 20 25 30

t = 0.4 ms

0 5 10 15 20 25 30

t = 1.2 ms

0 5 10 15 20 25 30

t = 1.6 ms

10

Spr

ay h

eigh

th w

[mm

]


15

5

00 5 10 15 20 25 30

t = 0.4 ms

0 5 10 15 20 25 30

t = 0.8 ms

0 5 10 15 20 25 30

t = 1.2 ms

0 5 10 15 20 25 30

t = 1.6 ms

0 5 10 15 20 25 30

t = 0.8 ms

0 5 10 15 20 25 30

t = 1.2 ms

0 5 10 15 20 25 30

t = 1.6 ms

8.9, λ = 0.57.5, λ = 0.66.1, λ = 0.74.6, λ = 0.93.2, λ = 1.41.8, λ = 2.50.4, λ = 12

[mol/m3]

700675650625600575550[K]

High

Low







Spr

ay h

eigh

th w

[mm

]


15

10

5

00 5 10 15 20 25 30

t = 0.4 ms

0 5 10 15 20 25 30

t = 0.8 ms

Spr

ay h

eigh

th w

[mm

]


15

10

5

00 5 10 15 20 25 30

t = 0.4 ms

0 5 10 15 20 25 30

t = 1.2 ms

0 5 10 15 20 25 30

t = 1.6 ms

10

Spr

ay h

eigh

th w

[mm

]


15

5

00 5 10 15 20 25 30

t = 0.4 ms

0 5 10 15 20 25 30

t = 0.8 ms

0 5 10 15 20 25 30

t = 1.2 ms

0 5 10 15 20 25 30

t = 1.6 ms

0 5 10 15 20 25 30

t = 0.8 ms

0 5 10 15 20 25 30

t = 1.2 ms

0 5 10 15 20 25 30

t = 1.6 ms

8.9, λ = 0.57.5, λ = 0.66.1, λ = 0.74.6, λ = 0.93.2, λ = 1.41.8, λ = 2.50.4, λ = 12

[mol/m3]

700675650625600575550[K]

High

Low





TempToral Change in the Impinging Spray Image with Exciplex Fluorescence Method- Pinj=120[MPa], Qinj=12.0[mg], Tw=550[K], ρ a=12.3[kg/m3], Zw=40[mm] -


30

25

20

15

10

5

0

35

0.0 0.5 1.0 1.5 2.0

Zw = 24Zw = 30Zw = 34Zw = 40

Time from impingement [ms]

Spr

ay ra

dius

Rw

[mm

]

0.0 0.5 1.0 1.5 2.0Time from impingement [ms]

0.0

2.5

5.0

7.5

10.0

12.5

Spr

ay h

eigh

t h w

[mm

]

Zw = 24Zw = 30Zw = 34Zw = 40

Spray Radius Rw Spray Height hw

Temporal Change in the Spray Radius and Height


Jiro SENDAS pray & Combustion Science Lab.

Doshisha University, Kyoto JAPAN

Thank you for your kind attention

　　　　　The END -完 -

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