Page 191 - konishipaper

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一一
Tr(z) T LM山 P MaKaP¥'-r M
L
Air
ea，i. . α，aλpn Tn
.，
x
L
J'
(ιt'，ぷ
Ta Air-白 elvapormixture
ern，i. . αfl l，i. . (Z) 内 (z) Tr(z)
x T仰
Fig，4. (Co101'online)Schematicilus七1'ationoftheatenuationof theIRrayandthe1'efractionoftheH←Ne1aserrayduetovapo1' absorptionandtemperatu1'evariation.
graybody.AstheIRthermalradiationemited企om theisothermalgraybodypasedthroughtheair，the spectralintensitywas1'educeto1α，:，> givenas
4 /T.'¥ paCta，>:= 例 > : Llne~T="
(1)
1a，>:
σεω-xTw4 Pa (J'εm.:>Tw'4
一一干_ e-.cx，.川= τ (7)
Thedensityofthefuelvapo1' isdeterminedbythe loga1'ithmic1'atiooftheequivalentwaltempe1'ature withoutfuelvaporTw'andwithfuelvapo1'Tw"mea- sured by the IR camera. In Eq. (12) the average spectralabsorptioncoe伍 cientα6isdeterminedex- perimentalywhenthesurfacedensityoffuelvapor Proisdete1'minedbytheequilibriumvaporconcentra- tionattheliquidsurface:
Liquidfuel
Equivalent ιI臼，"h←σC
SimpliちringEq.(9)gives ヨ?ヨ
4
jI“、 ト斗 Graybody
whereαa，>:istheabso1'ptioncoeficientoftheairhav-
出 ganaveragewavelengthof8to12μm，Paisthe
densityoftheai1'， andListhepathlength，whichis neadyequaltothetraylength，16σistheStefan- Boltzmannconstant，εm，:>istheemisivitysetingsof theIRcame1'aoperatinginthe8to12μmspectral
range，andTw isthewal ltemperatureoftheisother- malgraybody.Whenthewaltemperatureofthe graybodythroughtheairismeasuredbytheIRcam- era，thespectralintensity1a.h"isequivalenttothe intensityhavingtheequivalentwaltemperatu1'eTw' ofagraybody.Thenwewilconsiderthe1'adiationof intensity1fawithinanabsorbingandemitingfuel- 3. ErorAnalysis ai1'mixtureasshowninFig.4(b).Theintensity1fa，"h16
lSglvenas
r n 4 7 σ同u，}:.lW
X p仏αf伝'a:~.e一PI"C\:f;àぬ(Lφ一正吟)dχ
rpfnαfa，i;L r n 4
A. HolographicInteげerometry AsthelaserandIRrayspasth1'oughthemixtureof
fuel vapo1' and air， the 1'ays are bent in the direction oftheincreasingindexofrefraction.A 1'e仕actionof therayresult13inthretypesofe口 01':(a)ageometric e1'1'o1'inthepositionofthefringesduetodeflectionof cordinates，(b)aconcentrationerorduetotheva1'i- ationinconcentrationalongtheraypathcausedby de丑ection，and(c)aconcentrationero1' duetothe changeinpathlength.Theero1'thatisdueto(c)is
-DFn('(e，iL，
，I. . faλ 一 一 巴 !
σεfaμf 一 一守 一 守一 -
0
γσεIR
T
τ'T (8)
，>:~山JFH，
whereα弘:¥istheabsorptioncoe自 cient，Pfaistheden-
sity，εfa，"Xistheemisivity;andTfaisthetemperature negligiblysmal.Wenowpresentabriefdescription ofthefuel-airmixture，respectively.Asdesc1'ibed ofactors(a)and(b).Detailsoftheero1'analysiscan above，thespectralintensity1fa.h"isequaltothein- befoundinRefs.15-17.
tensityoftheequivalentwaltemperatureTw" ofa graybodywhenthesurfacetemperaturethroughthe fuel-airmixtureismeasu1'edbytheIRcamera.
Assumingωεよ 》 εfa，>:anddividingEq.(7)byEq.(8) yield
5728 APPLlEDOPTICS/Vo.l45，No.2/1August206
Figure5ilustratesthegeometricerorsOc+OT，the concentrationerorsLlPc+!lPT，.theefecte1'rorムPy， andthetotalerors.Themeasurementer1'o1'sare relativetotheequilibriumvaporconcent1'ationatthe liquidsurfacefor400C n-propanol.Intheexperi-
ωε8 ，>:Tω41τ)片e一附向ρ附内α叫附U内川.I内叫
1fn，:> (σ九五九41τ)e
σε四点u
eL(Pfa(\:fn，
~-Patl<，
x)
一附
h;，iL
/ 中 '¥4
= (;:") ， (10)
PfaCtaf，:¥一 Therefo1'etheresultisthefolowingequationprovid-
ingfuelvaporconcentration:
4 可 ITw'(0)l m=5imelTJ(0)j
(13) BysubstitutingEq.(12)intoEq.(5)orEq.(6)，the
temperature distribution Tr伊 uSlng
μ
can be calculated 1 1.Ni(z)入R R ( Ma¥
一一・
o r勺
・
4 /T.'¥ ×玩Zln《，T27
(14)
=一一一一一一. (9)
1
l/
jτ
一一一
(12)
、巴、t'1lstI'
川ν-HU mム一巾'川
、 FFI'ittt
n 4 一同
一
rl nド