Initial Condition Dependene of Dynamis and Evaporation of Polymer Spallation Partiles Flying in Polymer Ablated Arcs

Initial Condition Dependene of Dynamis and Evaporation of Polymer Spallation Partiles Flying in Polymer Ablated Arcs

著者 Nakagawa Takuya, Nakano Tomoyuki, Tanaka Yasunori, Uesugi Yoshihiko, Ishijima Tatsuo journal or

publication title

2015 3rd International Conference on Electric Power Equipment ‑ Switching Technology,

ICEPE‑ST 2015

number 7368325

page range 6‑11

year 2015‑10‑25

URL http://hdl.handle.net/2297/45478

doi: 10.1109/ICEPE-ST.2015.7368325

of Polymer Spallation Partiles Flying in Polymer Ablated

Ars

TakuyaNakagawa

1

, TomoyukiNakano

1

,YasunoriTanaka

1

, Yoshihiko Uesugi

1

, Tatsuo Ishijima

1 1

KanazawaUniversity, Kakuma,Kanazawa920-1192, Japan

Abstrat—We have developed a numerial model on

dynamisof spallation partiles ying in the polymer ab-

lated ars. We had found mirosized spallation parti-

les ejetedfrompolyamidematerials(Polyamide-6(PA6)

[−

^C

⁶

^H

¹¹

^ON

−] ⁿ

^{/Polyamide 66 (PA66)}

[−

^C

¹²

^H

²²

^O

²

^N

² −] ⁿ

⁾

bythermal plasma ontat. Inthis paper, effets of initial

onditionsforspallationpartilesyinginpolymerablated

ars on dynamis and evaporation of polymer spallation

partiles were investigated using the developed numerial

model. As initial onditions, pressure inside the polymer

ablatedar,theinitialpartilediameterandinitialveloity

of spallation partiles were treated to study their effets.

Under the given temperature and gas ow distributions

in speiedinitialonditions, thetrajetories of spallation

partiles yingin the polymer ablatedar were simulated

numerially,onsideringthetimevariationsinthetemper-

ature and the diameter of the partiles.The results show

thatthehighestightaltitudeofthePA6spallationpartile

yinginthePA6ablatedarisaffetedbytheinitialpartile

diameterandveloity remarkably.

IndexTerms—Ciruitbreaker,Currentinterruption,Ab-

lation,Spallation,Polyamide

I. INTR ODUCTION

Polymermaterialsarewidelyusedforquenhingham-

berwallsorfordieletriinsulationinmoldedaseiruit

breakers (MCCB) in a low-voltage eletri distribution

system.Thepolymermaterialsontatintensivearplas-

mas during a short-iruit fault or a ground fault, and

this ontat indues ablation of the polymer materials.

The polymerablation vaporauses alarge pressure rise

inthearquenhinghamber.Thisinduesgasowand

onvetionlossinthearplasma.Theproduedgasow

forestoexpandthe arplasma,andhelpsoolingdown

and quenhing it. In this way, Suh polymer ablation

remarkablyaffetstheinterruptionapabilityoftheiruit

breakers[1℄.Italsoaffetsthethermodynamisandtrans-

portpropertiesofarquenhingmedium.Ciruitbreakers

applyingthe polymerablation are widelydevelopedand

used[2℄. However,the interation between ar plasmas

andar quenhingpolymermediumshasnotrevealedin

detail.

In our previous work, we had observed not only

polymer ablation vapor but also miro-sized partiles

“spallation partiles” ejeted from polyamide materials

during the irradiation of indutively oupled thermal

plasmas(ICTPs)[3℄.Weallthisphenomenon“spallation

phenomenon”.Ithadbeenalsofoundedthatthespallation

absorptionforpolyamidematerials [4℄. Inthis ase,the

thermodynamisandtransportpropertiesofPA6ablation

vaporhardlyhangedduetoitswaterabsorption.Thisis

attributedtothefatthattheompositionofPA6ablation

vapor originally ontains H and O atoms omposed by

water. If the spallation phenomenon applys for the ar

quenhing,spallation partiles are expeted to penetrate

intothearore,whihanooldownitdiretly.There-

fore, suhappliation of spallation phenomenon forar

quenhingleadtoenhanethe arinterrupitonapability

of the iruit breaker. For this aim, it is neessary to

understanddynamisofthepartilesinthear plasma.

Inthispaper,anumerialmodelforaspallationpartile

motionandtemperature inreasewas used. Firstly,tem-

peratureandgasowdistributionsinthePA6ablatedar

werealulatedusinganumerialthermo-uidmodel[5℄,

[6℄,[7℄.EffetsofPA6ablation vaporonthe arplasma

suhas thehangeinthe thermodynamisandtransport

properties of ar medium, the energy loss due to the

ablation,themass exhangeandthe pressurerisedueto

theproduedgasowinthearplasmawereonsidered.

Under those omputed distributions in the PA6 ablated

ar,we simulated the motionandtemperaturevariations

ofPA6 spallation partileshavinganinitialveloityand

a partile diameter solving the equation of motion and

themass andenergyonservationequation[9℄. Through

this simulation, we ould understand the trajetory and

temperaturevariationof the partile inluding its phase

hangeandaderease inits partile diameter. Not only

initial parameters of PA6 partiles suh as its initial

veloity,partile diameterandejetion position butalso

the initial pressure in the PA6 ablated ar were varied

respetively in the present work. From the results, we

ould understand the ondition in whih PA6 partiles

anablateinthe arore.TheResultsindiated thatthe

highestightaltitudeofPA6spallationpartilesyingin

thePA6ablatedarisaffetedbytheinitialveloityand

partilediameterremarkably.

II. NUMERICALTHERMO-FLUIDANALYSISOF

POLYMERABLATEDARC

Forthe simulation inthe motionand the temperature

variationofPA6spallationpartilesyinginthePA6ab-

latedar,wehadtoalulateitstemperatureandgasow

distributionsatrst.Therefore,thenumerialthermo-uid

analysismodeltoalulatethosedistributionsisindiated

Fig.1. Shematisofthealulationtargetimagingtheardevie.

6 mm

50 mm

30 mm Polymer block

Polymer block Outlet

Electrode Calculation space

Fig.2. Calulationspaeforthetemperatureandgasowdistributions

inthepolymerablatedar.

A. Assumptions

Fig. 1 shows the alulation target imaging the ar

devieinthismodel. Inthealulationtarget,twoylin-

drial eletrodes are loated with a distane of 50 mm.

Eah of elerode has a diameter of 6 mm. One of the

eletrodesisinsertedintheylindrialpolymermaterial.

On the other hand, A length ofthe polymer ylinderis

50 mm. Inaddition, its inner diameteris6 mm, andits

external diameter is 30 mm. Inthis simulation, the ar

plasma ignites between the eletrodes. The ar ignition

spae is lledwith air at rst. The ontat between the

ar plasma and the ylindrial polymer material auses

the polymer ablation.Fig. 2 shows the alulation spae

inthismodel.Thealulationspaeistherosssetionof

theylindriallysymmetrialspaewiththeeletrodeand

theylinderialpolymershown as abrokenline olored

in red in Fig.2. It is divided into 104 grids inan axial

diretion,andinto 42gridsinaradialdiretion.

In alulating,the following assumptions are dened:

(i) the plasma is in loal thermodynami equilibrium;

onsequently,all relevant temperaturessuhas the ele-

tron temperature,the gastemperature andthe exitation

temperature are mutually idential. (ii) the plasma is

in optially thin for wavelengths greater than 200 nm.

For wavelengths of less than 200nm, 20% of the total

emission oefient is aounted for radiation loss to

onsider the effetive light absorption. (iii) the ow is

steady,laminarandaxisymmetri,withnegligiblevisous

dissipation.(iv) the alulationspae isthe symmetrial

spae.(v)theeletrieldgeneratesonlyintheaxialdi-

retion.(vi)thepropagationveloityofpressurewavesis

limited.(vii)the phenomenasuhasmeltingandboiling

ofthe eletrodematerials, the eletrode fall voltage and

theproessofeletronemission arenegleted.

B. Governingequation

OntheassumptionsshowninsetionII-A,thepolymer

ablated ar is onsidered to be governing by the mass

CALCULATIONCONDITIONSFORTHESTEAD Y-STATEANALYSISOF

THETEMPERATUREANDGASFLOWDISTRIBUTIONSINTHEPA6

ABLATEDARC.

Currentvalue DC50A

Lengthbetweentheeletrodes 50mm

Arquenhingpolymermedium PA6

Eletrodematerial Fe

TABLEII

THERMOD YNAMICPROPER TIESOFPA6

Meltingtemperature[K℄ 493.5

Thermaldeompositiontemperature[K℄ 717.6

Latentheatformelting[kJ/kg℄ 53.3

Latentheatforthermaldeomposition[kJ/kg℄ 187.6

Massdensity[kg/m

3

℄ 1140

Speiheatinsolid[J/(kgK)℄ 2617

Speiheatinliquid[J/(kgK)℄ 3031

Thermalondutivity[W/(mK)℄ 0.25

Emissivityofthesurfae 0.3

onservation equation, the momentum equation, the en-

ergyonservationandthe massonservationequationof

polymer ablation vapor. These equationsare mentioned

inanotherpaper[8℄.

In this omputation, the mass prodution rate due

to ablation

S _p ^C

^was approximately alulated only for the neighbor to the polymer wall[8℄. The ablation ux

Γ _ab

used foralulating it was omputed by the Hertz- Knudsen relation [8℄. On the other hand, the deposition

ux

Γ _dep

wasevaluatedbythe randomux[8℄.

C. Calulationonditions

ThealulationonditionsaresummarizedinTable.I.

In this alulation, the urrent value was set to DC 50

A. The ylindrial polymer material was dened to be

madeof PA6. The eletrode material was Fe. The ther-

modynamipropertiesofPA6requiredinthisalulation

issummarizedinTable.II.

D. Calulationresults

The alulated two dimensional temperature and gas

ow distributionsinthe PA6 ablated ar atDC 50 Ais

showninFig.3.FromFig.3thetemperatureontheaxis

ishigherthanthosenearthe polymerinnerwall.Onthe

otherhand, the gas ow veloitybeomehighertoward

thegasoutlet.

Fig. 4(a) shows the radial temeperature distributions

at eah axial position of

z = 30

^{mm and}

z = 50

mminthe PA6 ablatedar.Asseen, the temperatureon

the axis reah above 11000 K. On the other hand, the

regionsnearthe innerpolymerwallisooledbythePA6

ablation vapor, andthe temperaturethere beome lower

than1000K.TheproduedPA6ablationvapormakesthe

arshrinkingintheradial diretion

Theradialgasowveloitydistributionsateahaxial

position of

z = 30

^{mm and}

z = 50

^{mm in the PA6}

ablatedarareshowninFig.4.FromFig.4thegasow

veloityonthegasoutlet

z = 50

^{mm ishigherthanthat}

0 1 2 3 4 0

2 4 6 8 10 12

z=30mm

z=50mm

T em p er a tu re [ k K ]

Radial position [mm]

(a)Temperature

0 1 2 3 4

0 20 40 60 80 100 120 140 160 180 200 220 240

z=30 mm

z=50 mm

G a s fl o w v el o ci ty [ m /s ]

Radial position [mm]

(b)Gasowveloity

Fig.4. Radialtemperatureandgasowveloitydistributions inthe

PA6ablatedar.

0 10 20 30 40 50

4 3 2 1 0 1 2 3 4

Ejection area of spallation particles

Polymer

Polymer

Electrode

R a d ia l d ir ec ti o n [ m m ]

Axial direction [mm]

Fig.5. Calulation spae for the simulation on dynamis and the

temperaturevariation ofspallation partilesyingin thePA6ablated

ar.

at

z = 30

^{mm. The ejeted PA6 ablation vapor indues}

suhdifferene.

III. SIMULATIONONDYNAMICSANDTEMPERATURE

VARIATIONOFSPALLATIONPARTICLESEJECTEDIN

THEPA6ABLATEDARC

A. Calulation spae for simulation on dynamis and

temperaturevariationofspallationpartiles

Fig. 5 showsthe alulation spae for the simulation

on dynamis andthe temperaturevariation ofspallation

partiles ying in the PA6 ablated ar. This simulation

uses the temperature and gas ow distributions in the

PA6 ablated ar alulated in the previous setion. The

alulation spae is devided into 103 grids in an axial

diretion and 84 grids ina radial diretion respetively.

Spallationpartilesareejetedfromthelowerwallofthe

ylindrialpolymer materialshown inFig.5.

B. Modelofspallationpartile

1) Momentumequationof spallationpartiles ejeted

inthepolymerablatedar: Inthisalulation,spallation

partileswereassumedtobeompletelyspherial.Itwas

alsoassumedthatthemotionofspallationpartilesying

inthearplasmaareaffetedonlybythedragforefrom

the visosity of the ar and by the gravity. The image

and the denition of eah parameter in the motion of

spallationpartileshowinFig.6.Onthoseassumptions,

the momentum equation for a partile exposed to the

polymerablatedar anbewrittenas[12℄

du p

dt = − 3

4 C D (u p − u) U R

ρ ρ p d p

+ g

⁽¹⁾

dv p

dt = − 3

4 C D (v p − u) U R

ρ ρ p d p

(2)

U R = q

(u p − u) ² + (v p − v) ²

⁽³⁾

C D =



 

 

 

 



 

 

 

 



24

Re Re ≤ 0.2

24

Re 1 + ₁₆ ³ Re

0.2 < Re ≤ 2.0

24

Re 1 + 0.11Re ^0.81

2.0 < Re ≤ 21.0

24

Re 1 + 0.189Re ^0.62

21.0 < Re ≤ 200

(4)

Re = ρU R d p

µ

⁽⁵⁾

where

U _R

is the relative veloity between the partile andthe arplasma

，C _D

^{isthe dragoefient}

， g

^isthe

gravitationalaeleration,

u _p

isthe axial veloityofthe partile

， v p

^{istheradialveloityofthepartile}

，u

^isthe

axialveloityofablationvapor

， v

^{istheradialveloityof}

ablationvapor

，ρ _p

^{isthe massdensity ofthe partilein}

solidandliquidphases

，ρ

^{isthemassdensityofablation}

vapor

，d _p

is thepartilediameter

， µ

^{is thevisosity of}

ablationvapor,

Re

^{isReynoldsnumber.Reynoldsnumber}

inthisomputationwas typiallyinrangeof0-13.1.

2) Energy onservationequation andmass onserva-

tion equation of spallation partile: The temperature

insidethe spallation partile an be non-uniformdue to

its lower thermal ondutivity. Therefore, the tempera-

ture distribution an be produed inside the parile. To

onsider this temperature distribution, the partile was

divided into 20 shells shown in Fig. 7. We dene the

temperature

T p (r, t)

^{and the liquid fration}

χ(r, t)

^of

eah shell, and these parameter depend on the radial

position

r

^{and the time}

t

^{. We also assumed that the}

u d

F D

g

Fig.6. Exerteddragforeandgravityonaspallationpartileying

ingasow.

Fig.7. Conept ofaspallationpartiletreatingitsinnertemperature

gradient.

thermal deompositionof the partile oured when its

temperaturereahedto

T e

^.

Inside the partile, thermal ondutionbetween inner

shellsduetothe radialtemperaturegradientwasonsid-

ered for any temperaturerange [8℄. On the other hand,

more omplexphenomenon suhas thermal ondution

totheinnershells,heattransferfromthesurroundingar

plasma,theradiationlossfromthesurfaeofthepartile

wereonsideredattheoutershell[8℄.Thetemperatureand

the liquid fration at the outer shell were alulated by

theequationsmentionedinanotherpaper[℄.Thederease

inthe partilediameterduetoitsthermaldeomposition

was omputedbythe massofits ablation[8℄.

C. Calulationondition

The alulation onditions of the spallation partile

for the simulation were summarized in Table. III. We

assumedthatthePA6partilesejetedfromthePA6inner

wallattheaxialpositionof30mmandtheradialposition

of3mmrandomly.Theinitialtemperatureofthepartile

was set to 450 K orresponding to the temperature of

the innerwall.Itsinitialveloitywassetto5m/sdueto

itsexperimentalmeasurementinthepreviouswork[9℄.In

addition,weestimatedtheinitialdiametertobe0.12-0.28

mmbytheomparisonbetweentheexperimentaltrajeto-

riesofthepartilesyingduringtheirradiationofICTPs

anditsnumerialtrajetoriesinanotheralulation.From

thiswork,theinitialpartilediameterwassetto0.2mm

in this simulation.We dened the angle

α

^{ofthe initial}

veloityshowninFig.8andtheangle

α

^wassetto

±

⁹

^◦

^,

±

²⁷

^◦

^and

±

⁴⁵

^◦

^.

IV. CALCULATIONRESULTSANDDISCUSSION

Fig.9showsthetrajetoriesofthePA6partilesejeted

INITIALCONDITIONSOFTHESPALLATIONPAR TICLEFORTHE

SIMULATIONOFITSD YNAMICSANDTEMPERATUREVARIATIONIN

THEPA6ABLATEDARC

Treatedpolymermaterial PA6

Initialveloityofthepartile[m/s℄ 5.0

Initialpartilediameterofthepartile[mm℄ 0.2

Initialtemperatureofthepartile[K℄ 450

Initialejetingpositionofthepartile[mm℄ (

z

,

r

)=(30,3) Divisionnumberofthepartilediameter 20

Fig.8. Denitionofanangle

α

oftheinitialveloityofaspallation partile.

shownlinesoloredwithrespetiveolors.Foranyangle

α

^{, the partile penetrates into the} temperatureregion of about7000Kto9000Kandevaporatesompletelythere.

Thismay ooldown the high temperatureregionwhih

the PA6 ablation vapor an't do, and onsequently the

arplasma isexpetedtobe quenhedeffetivelybythe

penetrationofspallationpartiles.

In this alulation, the time variations in the tem-

perature of eah shell and the partile diameter were

alulated foreah angle

α

^{. These show in Fig. 10 for}

α

⁼⁹

^◦

^and

α

⁼²⁷

^◦

^.Thetime

t

^{isreferredtotheinitiationof}

thepartileejetion.At

α

⁼⁹

^◦

^,thetemperatureintheouter shell inreases due to the exposition to the ar plasma.

Around

t

⁼¹⁵

µ

^{s,it reahesthe melting} temperatureand keeps the temperature. This attributes to the fat that

the energy whih the partile is given by the ar is

onsumedfor the latent heat for its melting. Afterthat,

the temperatureinreases again, andit reahesthe ther-

maldeompositiontemperatureat

t

⁼⁴⁵

µ

^{s. Thepartile}

diameter dereases at the same time. The temperatures

of the inner shells inrease one after another after its

ompletelythermaldeomposition.Thepartilediameter

dereases due to thermal deomposition of the shells,

andthepartileompletelydeomposesaround

t

⁼⁴⁰⁰

µ

^s.

Suh timevariations inthe temperature andthe partile

diameteran be seen similarly for every

α

^{. From these}

results, we an expet that the spallation phenomenon

mayleadtotherapidlyarquenhingeffet.

A. Initialonditiondependene ofdynamisandevapo-

rationofpolymerspallationpartiles

Byusingthismodel,weinvestigatedtheinitialondi-

tiondependeneofdynamisandevaporationofthePA6

partilesejeted inthePA6ablatedar.Inpresentwork,

theinitialveloity,the partilediameterandtheejetion

positionofthepartileandtheinitialpressureinthePA6

ablated ar were varied respetively. Aording to the

hangeoftheseparameters,thevariationsin thehighest

4 3 2 1 0 1 2 3 4

!

R a d ia l p o si ti o n [ m m ]

Axial position [mm]

!

100%PA6 ablation vapor , PA6 Initial temp 450 K Initial velocity 5.0 m/s Grain diameter 0.2 mm

Electrode

Polymer

Polymer

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 1.1E4 1.2E4 1.3E4 1.4E4 [kK]

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

0 10 20 30 40 50

Fig.9. TrajetoriesofthePA6spallationpartilesejetedfromthelowerwallattheaxialpositionof30mminthePA6ablatedar.

10 ^-5 10 ^-4 10 ^-3

0.0 0.1 0.2 0.3

Time [s]

D ia m et er [m m ]

400 450 500 550 600 650

700 750 Outermost Shell (1st shell) 2nd shell 3rd shell

T em p er a tu re [K ]

(a)

α

=9

◦

10 ^-5 10 ^-4 10 ^-3

0.0 0.1 0.2 0.3

Time [s]

D ia m et er [m m ]

400 450 500 550 600 650

700 750 2nd shell 3rd shell

Outermost Shell (1st shell)

T em p er a tu re [K ]

(b)

α

=27

◦

Fig.10. Timevariations in the temperature ofeah shell and the

partile diameterfor

α

=9

◦

and

α

=27

◦

Firstly,theinitialveloityofthe partilewashanged

from1-25m/s, andthe otherparameterswere settothe

samevaluessummarized inTable.III.Fig.11showsthe

initialveloitydependeneofthehighestightaltitudeof

the partilesying in the PA6 ablated ar. As seen, the

highestightaltitudeofthepartiledependsonitsinitial

veloityremarkably.The highestightaltitudeinreases

withinreasing its initial veloity.Todeompositionand

ooldown the ar ore, the partile may be required to

havethe initialveloityhigherthan13m/s.

Seondly,wehangedtheinitialpartilediameter0.1-

0.5mm.TheothervalueswerexedshowninTable.III.

Fig.12showstheinitialpartilediameterdependeneof

the highest ight altitude of the partile ejeted in the

PA6 ablated ar.InFig.12,thehighest ightaltitudeof

0 5 10 15 20 25

0 1 2 3 4 5 6

Gas:100%PA6 ablation vapor Polymer material: PA6 Initial temperature: 450 K Initial grain diameter: 0.2 mm

Initial ejection position: (z, r)=(30 mm, 3 mm)

H ig h es t fl ig h t a lt it u d e [m m ]

Initial velocity [m/s]

0 5 10 15 20 25

0 1 2 3 4 5 6

Fig.11. Initialveloitydependeneofthehighestightaltitudeofthe

partilesejetedinthePA6ablatedar.

ofthepartilediameter.Thepartilealsoneedstohaving

the initialpartilediameterof0.32 mm toreahthe ar

ore.Thus,thepartilehavinganinitialpartilediameter

lessthan0.32mm annot beexpetedtoooldownthe

aroreeffetively.

Next, the initial position from the partiles ejeted is

varied25-45mmattheaxialposition.Wesetthe other

parametertoeahvalueasshowninTable.III.Theinitial

ejetionpositiondependeneofthepartileejetedinthe

PA6 ablatedarisshowninFig.13.Asseen,thehighest

ightaltitude ofthe partile ejeted from eahposition

hardlyhanges. Atanypositions, the partiles penetrate

into thear tothe heightofabout 2mm. Therefore,we

anndtoobtaintheoolingeffetgivenbythepartiles

uniformlyinthePA6 ablatedar.

Finally,wevariedtheinitialpressureinthePA6ablated

ar 0.1 - 2.0 MPa. The parameters of the partile were

set to the same values shown in Table. III. Fig. 14

showstheinitialpressuredependeneofthehighestight

altitudeofthepartileejetedinthePA6ablatedar.The

highestightaltitudeofthe partilehardlyhangeswith

inreasingtheinitialpressureinthePA6ablatedar,and

italmostkeepstheonstantvalueofabout1.8mm.Thus,

theinreaseofthe initialpressureinthePA6ablatedar

isnotexpetedtoaffetthedynamisandevaporationof

0.1 0.2 0.3 0.4 0.5

Gas: 100%PA6 ablation vapor Polymer material: PA6 Initial temperature: 450 K Initial velocity: 5.0 m/s

Initial ejection position: (z, r)=(30 mm, 3 mm)

H ig h es t fl ig h t a lt it u d e [m m ]

Initial grain diameter [mm]

0 1 2 3 4 5 6

Fig. 12. Initial partile diameter dependene of the highest ight

altitudeofthepartileejetedinthePA6ablatedar.

0 1 2 3 4 5 6

Gas: 100%PA6 ablation vapor Polymer material: PA6 Initial temperature: 450 K Initial velocity: 5.0 m/s Initial grain diameter: 0.2 mm

H ig h es t fl ig h t a lt it u d e [m m ]

Initial ejection position on the axis [mm]

25 30 35 40 45

Fig.13. Initialejetedpositiondependeneofthehighestightaltitude

ofthepartile ejetedinthePA6ablatedar.

V. SUMMARY

In this paper,the initial parameter dependeneof the

highestightaltitudeofthePA6spallationpartileying

inthePA6ablatedarwasinvestigatedusingthenumeri-

almodelinthedynamisandevaporationofthepartile.

Forthis aim, the temperature andgas ow distributions

in the PA6 ablated ar were alulated at rst. We

omputed the trajetories of the partiles ying under

those distributions in the PA6 ablated ar, onsidering

thetimevariationsinthetemperatureineahshellofthe

parileandthepartilediameter.Thismodelalsoonsider

the temperaturedistributioninsidethepartileleading to

meltingandthermaldeompositionofthepartile.Inthis

model,wevariedtheinitialparametersofthepartilesuh

as itsinitialveloity,itspartilediameteranditsejetion

position.The initial pressure in the PA6 ablated ar was

also hanged.Theresultsindiatethat thedynamisand

evaporation of the partile an be affeted remarkably

by itsinitialveloityandpartilediameter.On the other

hand, the initial ejeted position andthe initialpressure

hardlyaffetsthose.Fromtheseresults,thearquenhing

effetofthespallationphenomenonisexpetedtodepend

0 1 2 3 4 5 6

H ig h es t fl ig h t a lt it u d e [m m ]

Initial pressure [MPa]

0.1 0.5 1 2

Gas: 100%PA6 ablation vapor Polymer material: PA6 Initial temperature: 450 K Initial velocity: 5.0 m/s

Initial ejection position: (z, r)=(30 mm, 3 mm)

Fig.14. Initial pressuredependeneofthe highestight altitudeof

theejetedinthePA6ablatedar.

partileremarkably.

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