Influences of Compression Ratio and Methane Additive on Combustion Characteristics in a DME-HCCI Engine

Transcription

1 Copyright SAE Intrntionl --7 Influns of Comprssion Rtio n Mthn Aitiv on Comustion Chrtristis in DME-HCCI Engin Hiroki Nomur, Tkuy Muto n Syk Nishimi Nihon Grut Univrsity Hio Shoji Nihon Univrsity Kzunori Yoshi Diw Siko, In. ABSTRACT In this stuy, sptrosopi mtho ws us to msur th omustion hrtristis of tst isl ngin whn oprt on imthyl thr (DME) unr homognous hrg omprssion ignition (HCCI) omustion pross. A numril nlysis ws m of th lmntry rtions using Chmkin. to prform th lultions. Th rsults of th nlysis show tht omprssion rtio hngs n th mthn itiv influn th utoignition timing in th DME-HCCI omustion pross. In th xprimnts, ruing th omprssion rtio ly th tim of th pk ylinr prssur until ftr top ntr, thry inrsing th rnkshft output n thrml ffiiny. Th ition of mthn nl th DME-HCCI ngin to provi rnkshft output quivlnt to tht sn for isl ngin oprtion t low quivln rtio. This ppr isusss ths ffts in rfrn to th xprimntl n lult rsults. historis wr msur to invstigt th ftors influning th vlopmnt of low-tmprtur flms tht influn th ourrn of utoignition. Dimthyl thr (DME) ws us s th min tst ful n mthn ws us s ful itiv. On ftur of DME is tht it n prou from wi vrity of mtrils. It is lso hrtriz s ing ln nrgy sour us its moluls ontin oxygn ut not sulfur. Furthrmor, its tn numr is qul to or highr thn tht of isl ful. For ths rsons, it hs ttrt ttntion in rnt yrs s n ltrntiv ful for isl ngins. This ppr isusss th influn of omprssion rtio hngs n th mthn itiv on th omustion hrtristis of n HCCI tst ngin whn oprt on DME. A omprison is lso m twn th xprimntl t n th rsults of lultions prform with Chmkin. in numril nlysis of th lmntry rtions. INTRODUCTION In rnt yrs, grt l of rsrh hs n on on homognous hrg omprssion ignition (HCCI) omustion [,,,,], whih n simultnously ru missions of nitrogn oxis (NOx) n prtiult mttr (PM) tht usully rquir tr-off with rspt to th omustion gs tmprtur. Th HCCI omustion pross hs th vntg of otining oth high ffiiny n low missions us th ngin n oprt in ln mixtur rgion yon th orinry limits of flm propgtion. Howvr, HCCI omustion hs th rwk tht it is iffiult to ontrol th ignition timing n th omustion prio. Th ojtiv of this stuy ws to gin furthr insights for xpning th oprting rgion of HCCI ngins n hiving ttr ontrol of ignition timing. A sptrosopi mtho ws us to invstigt th hvior of omustion intrmit prouts, n ht rls TEST FUELS CHARACTERISTICS OF DME AND METHANE Th min tst ful us in th xprimnts ws imthyl thr (DME). In th ln ful xprimnts, mthn ws to th min ful of DME to rt th tst ful. Th proprtis of h ful r givn in Tl []. DME hs ttrt intrst s n ltrntiv ful for HCCI ngins [7]. This ful hs ngtiv tmprtur offiint rgion in whih th ignition ly is not shortn vn if th tmprtur is highr t th onst of omprssion. Th omustion pross is hrtriz y multipl-stg ht rls ttriut to low-tmprtur rtions (LTR) n to high-tmprtur rtions (HTR). Bus mthn hs high utoignition tmprtur n tn numr of, mixing it with DME is n

2 fftiv wy to ontrol th ignition timing. Whil DME shows two-stg ht rls pttrn u to LTR n HTR, mthn isplys only singl-stg ht rls pttrn inu y HTR. OXIDATION PROCESSES OF DME AND DME/METHANE Th oxition rtion pross of th DME/mthn ful ln is outlin in Fig. [,9]. DME rtions r ivi into two prosss: on tht pros from th first ition of O n follows pth involving son ition of O pning on th tmprtur rgion (not s () in th figur), n nothr pross in whih th rtion pros without th ition of O (not s ()). In th low-tmprtur rgion low K, th rtion is lrt y hin-rnhing stp (ool flm rgion). As th tmprtur riss furthr, th pross hngs to rtion (), whih is hin propgtion stp, so th lrtion of th rtion ss (ngtiv tmprtur offiint rgion, NTC [,,,] A susqunt tmprtur ris inus rtion (), rsulting in th proution of xss OH rils (lu flm rgion) n ling to utoignition. In onjuntion with th tmprtur ris, two-stg ignition [] ours owing to th progrssion from ool flm through th NTC rgion to utoignition, s th rtions pro from () to (). In th s of th DME/mthn ful ln, rtion () inu y DME tks pl in th low-tmprtur rgion. As th tmprtur susquntly inrss, th pross pros to rtion (), t whih point th OH rils prou from H O r suppli to mthn. Mthn tivly unrgos its initil H-tom strtion rtion, n its oxition rtion pros to rtion (). Ths rtions giv ris to two- or vn thr-stg ignition. It is rport tht th rtion pross hr involvs th proution of HCHO n CO y DME (LTR), th proution of CO y DME (st HTR), n th oxition of CO n mthn (n HTR). EXPERIMENTAL CONDITIONS Tl Proprtis of tst fuls Ful DME Mthn Molulr Fomul CH OCH CH Ctn Numr > Auto-ignition Tmp [K] 9 Low Ht Rls Vlu [MJ/kg].. Stoihiomtri A/F Rtio [kg/kg].9.9 (Extrnl H-tom strtion y OH) +OH,O,HO +O +OH,O,H +M,O,H CH CH HCO HCO CO >K Chin Brnhing High Tmprtur β-sission H + O OH + O Rtion ( Smllr R ) CH,CH Aumult HO K CHOCH thrml omposition HO (out OH + OH K) Blu Flm + O ( st O-ition ) Chin Propgtion Ngtiv 9K~ CHOCHOO CHOCHOOH CHOCHO + OH Tmprtur K + O ( n O-ition ) Coffiint OOCHOCHOOH Chin Brnhing HOOCHOCHOOH HOOCHOCHO + OH <K Cool Flm OCHOCHO + OH Fig. Chmil rtion pross of mthn/dme ful ln Tl Spifitions of tst ngin -Cyl Air-ool Engin Numr of Cylinrs Bor Strok 7 mm Displmnt 99 m Comprssion Rtio () : Comprssion Rtio (Comprssion rtio hngs) Comprssion Rtio (DME/mthn) Vlv Arrngmnt Typ of Piston Mthn Oxition Rtion 9:,:,7:,:,:, :,:,:,:,: :,:,: Ovrh vlvs (OHV) Rntrnt TEST EQUIPMENT AND CONDITIONS Th tst ngin us in this stuy ws n ir-ool singl-ylinr isl ngin, hving th spifitions givn in Tl. Th onfigurtion of th tst quipmnt us is shown in Fig.. A rystl prssur trnsur ws instll in th top of th ylinr h to msur th ylinr prssur. In orr to invstigt th ngin oprting onitions, msurmnts wr m of th omustion hmr innr wll tmprtur T W, intk ir tmprtur T IN n xhust gs tmprtur T EX. All fuls wr introu into prmixr [], instll pproximtly, mm upstrm of th intk vlv, for formtion of th prmix mixtur. Th onfigurtion of th ful supply systm is shown shmtilly in Fig.. Th ht rls rt n ril light mission hvior wr nlyz unr h st of oprting onitions. Th LTR n HTR finitions us in nlyzing th ht rls rt r shown in Fig.. Th onst tim of LTR ws fin s th point whn th ht rls rt show positiv vlu (i.., grtr thn ) n th onst tim of HTR ws fin s th point of th lowst ht rls rt in th intrvl twn th pk ht rls rt of LTR n th pk ht rls rt of HTR (i.., th point whr th ht rls rt gn to ris gin ftr rsing). Flm light in th omustion hmr ws smpl y mns of qurtz

3 osrvtion winow holr tth to th top of th ylinr h. Th smpl flm light pss through n optil fir l hving or imtr of mm n ws introu into polyhromtor [,7],whih sprt th light into wvlngths of 9. nm, orrsponing to th hrtristi sptrum of HCHO, n. nm, orrsponing to tht of th OH ril [,9,].Th wvlngth rsolution of th polyhromtor ws. nm. Following sprtion, th light t h wvlngth ws f into photomultiplir, n th rsptiv output voltg ws rgr s th light mission intnsity. A spr ws insrt twn th ylinr n th rnk s to vry th ngin omprssion rtio ε whil running th ngin t onstnt sp of N = rpm. Th omprssion rtio ε ws ru in inrmnts of on ovr rng from 9: to :. In th xprimnts, th quivln rtio φ of th fuls ws vri in rng tht llow th tst ngin to oprt t ths omprssion rtios. In th xprimnts using th DME/mthn ful ln, th omprssion rtio ws vri mong thr lvls of ε =, n :, whil kping th ngin sp onstnt t rpm. Th quivln rtio of DME in th ful ln ws kpt onstnt, n tht of mthn ws vri in rng tht i not x th quivln rtio of DME. NUMERICAL ANALYSIS OF ELEMENTARY REACTIONS Th oxition rtions of DME wr nlyz numrilly n th rsults wr ompr with th t msur xprimntlly with th tst ngin. Th IC Engin softwr in Chmkin. ws us to prform th lultions in th numril nlysis of th lmntry rtions [].Th shm us ws th lmntry rtion mol propos y Currn t l. [,,], involving lmntry rtions n 7 hmil spis. Th oprting onitions us in th lultions wr th sm s thos us in th xprimnts. RESULTS AND DISCUSSION INFLUENCE OF VARYING COMPRESSION RATIOS ON DME-HCCI COMBUSTION Wvforms msur for vrious omprssion rtios Figurs n show typil wvforms msur for ngin oprtion unr HCCI omustion t onstnt ngin sp N of rpm, rltivly low quivln rtio φ of. n vrying omprssion rtios ε of 9, 7,,,, n :. Th rnk ngl θ (g.) is shown long th horizontl xis. From th top, th vrtil xs init th ylinr prssur P (MP), ht rls rt (, J/g.) foun gomtrilly from n initor Ht Rls Rt [J/g.] Cylinr Cntr Q H mx LTR Q L mx. Qurtz Osrvtion Winow Prssur Trnsur θ LS Dynmomtr Fig. Configurtion of ful supply systm L S Prsonl Computr θ HS Engin HTR Optil Fir Polyhromtor Photomultiplir Crnk Angl Pikup Low-Pss Filtr Cylinr Cntr ntr A-D Convrtr Fig. Configurtion of tst quipmnt Lminr Flowmtr Mtr Intk Air Surg Tnk (.m ) Cylinr Cntr Intk Air Qurtz Osrvtion Winow θ LS : Onst Tim of LTR Q Lmx : Pk Ht Rls of LTR θ HS : Onst Tim of HTR Q Hmx : Pk Ht Rls of HTR L: Durtion of LTR S: Amount of Ht Gnrt y LTR Crnk Angl, θ [g.] Fig. Dfinitions of LTR n HTR 7. K-typ Shth Thrmooupl igrm, n th light mission intnsity E OH (V) t. nm, orrsponing to th OH ril [,], n th light mission intnsity E HCHO (V) t 9. nm, orrsponing to HCHO [,,7], t th osrvtion point in th φ. Mss Flow Controlr Control Unit Prmixr Control Unit mm. φ K-typ Shth Thrmooupl Mhtn Gs Cylinr Mss Flow Controlr Cylinr H DME Gs Cylinr Exhust Gs

4 omustion hmr. Th hrging ffiiny η (%), xhust gs tmprtur T EX (K) n omustion hmr innr wll tmprtur T W (K) r shown low th rnk ngl s initors of th ngin oprting stt in this xprimnt. Th ylinr prssur wvforms in Figs. n show tht th ylinr prssur gn to ris shrply t n rlir rnk ngl with highr omprssion rtio. In th s of low omprssion rtio of ε = : or :, th shrp ris in th ylinr prssur wvform ourr in th viinity of top ntr (TDC). Ths rsults init tht lowring th omprssion rtio shift th pk ylinr prssur to point ftr TDC. Th wvforms in th figurs minly show pttrn of two-stg ht rls. This pttrn of multistg ht rls is hrtristi of omprssion ignition omustion of DME. Th first n son stgs r initiv of LTR n HTR, rsptivly. It is si tht omprssion ignition rtions with DME thortilly show pttrn of thr-stg ht rls, onsisting of th first-stg LTR tht prou formlhy, Light Light Emisson Emission Intnsity Intnsity E OH P [MP] rpm φ DME =. P r s s u r Crnk Angl, θ [g.] ε η [%] T EX [K] T W [K] : HCCI : HCCI : HCCI 79. H. R. R.. n m (O H r i l) 9. n m (H C H O ) Fig. Msur wvforms ( High omprssion rtio, ε ).... E HCHO son-stg HTR tht prou th CO ril, n thir-stg HTR tht prou CO. Howvr, s rport [] lswhr, it hs n osrv tht th sonn thir-stg rtions my intgrt into singl stg ompnying n inrs in th quivln rtio. Th rsults otin in this stuy show tht th son- n thir-stg rtions wr lso intgrt t low quivln rtio s rsult of inrsing th omprssion rtio. Figur 7 shows typil ht rls wvforms msur for HCCI omustion t n quivln rtio of φ =. n vrying omprssion rtios of ε = 9, 7,,, n :. Lin is for th LTR onst tim θ LS n lin is for th HTR onst tim θ HS. In Fig., th LTR onst tim θ LS is shown long th x-xis, th quivln rtio long th y-xis n th mximum Q Lmx of LTR long th z-xis. It is sn in Figs. 7 n tht th LTR onst tim shift to ltr rnk ngl s th omprssion rtio ws ru. As th omprssion rtio is ru, th omprssion prssur t th sm rnk ngl is lowr ompr with tht for highr omprssion rtio. Light Light Emission Emisson Intnsity E OH P [MP] rpm P r s s u r φ DME =..... H. R. R. 9. n m (H C H O ). n m (O H r i l) - - Crnk Angl, θ [g.] ε η [%] T EX [K] T W [K] : HCCI. : HCCI 7. 7 : HCCI. Fig. Msur wvforms ( Low omprssion rtio, ε ).... E HCHO Th Mximum Vlu of LTR, Q Lmx [J/g.] Ht Rls Rt, DME-HCCI N = rpm ε=9 ε=7 ε= ε= ε= ε= Comprssion Rtio, ε TDC Crnk Angl, θ [g.] Fig. 7 Influn of omprssion rtio on L 9 7 T.D.C Onst of LTR, θ LS [g.] Low Comprssion Rtio - Ln Rih Equivln rtio, φ Fig. Msur wvforms ( Vrying omprssion rtio ε )

5 Aoringly, it tks longr rnk ngl intrvl for th in-ylinr gs to rh th tmprtur lvl for th onst of LTR, whih xplins this shift to ltr rnk ngl. Th tmprtur ris originting from th LTR is lso ly to th xtnt tht θ LS shifts to ltr rnk ngl, whih mns tht th HTR onst tim θ HS lso movs to ltr rnk ngl s rsult. Th mximum Q Lmx of LTR inrs with lowr omprssion rtio. Figur 9 shows th LTR urtion s funtion of th quivln rtio φ. Th LTR urtion L m longr s th omprssion rtio ws ru. Tht n xplin y th ft tht th rtions slow own n pro t slow rt ompnying rution of th omprssion rtio. Th ht rls from LTR is shown in Fig. in rltion to th quivln rtio φ. It is sn tht th ht rls from LTR inrs t lowr omprssion rtio. Thr min ftors r thought to rsponsil for inrsing th in-ylinr gs tmprtur in th progrssion to HTR. Thy r th tmprtur ris u to omprssion of th gs y piston motion, th tmprtur ris u to ht rls from LTR, n th trnsfr of ht to th gs from th omustion hmr wlls. In th rnk ngl intrvl from 9 g. for top ntr (BTDC) to TDC, th piston sp oms slowr t ltr rnk ngls, with th rsult tht th gs tmprtur riss mor slowly u to omprssion. Aoringly, th progrss of LTR uring tht intrvl prsumly ount for th inrs ht rls. With high quivln rtio of φ =. or mor n low omprssion rtio ε of :, th ht rls from LTR rs slightly. It is lso sn in Fig. tht, t omprssion rtio of :, th LTR urtion show lrgr rt of rs with n inrsing quivln rtio ompr with th othr omprssion rtios. At omprssion rtio of :, it is ssum tht ht trnsfr from th ylinr wlls n th umult nrgy of th in-ylinr gs h lrg fft on th gs tmprtur, with th rsult tht th tmprtur lvl for th onst of high-tmprtur oxition rtions ws rh in short prio of tim, whih woul ount for th shortr LTR urtion. Aoringly, vn though th LTR mximum Q Lmx inrs in th rgion of high quivln rtio t omprssion rtio of :, th shortr LTR urtion prsumly ru th mount of ht rls from LTR. Light mission hvior of intrmit prouts Th light mission intnsity wvforms of th intrmit omustion prouts in Figs. n init tht th onst of shrp ris in light mission intnsity shift to ltr rnk ngl s th omprssion rtio ws ru. Tht shift to ltr rnk ngl ourr inintl to th HTR onst tim θ HS. Bus th inrs uring th urtion of LTR, it n infrr tht low-tmprtur flm (ool flm) ourr in tht intrvl. Howvr, no orrsponing Durtion of Low-tmprtur Rtions, L [g.] Ht Rls from Low-tmprtur Rtions, S [J] Equivln Rtio, φ Fig. 9 Durtion of low-tmprtur rtions ( Vrying omprssion rtio ε ) ε =: ε =: ε =: ε =: ε =: ε =: ε =7: ε =: ε =9: Equivln Rtio, φ Fig. Ht rls from LTR ( Vrying omprssion rtio ε ) ε=: ε=: ε=: ε=: ε=: ε=: ε=7: ε=: ε=9: hvior is osrv in th light mission intnsity wvform in th xprimntl rsults for φ =. us light mission from low-tmprtur flm is xtrmly fint. Figur shows typil wvforms msur for ngin oprtion unr DME-HCCI omustion t omprssion rtio ε of : n n quivln rtio φ of.. Figur shows th wvforms msur unr th sm oprting onitions whn th rsolution of th polyhromtor ws st slightly highr thn th norml lvl for HCHO lon. In th rgion not s A in Fig., light mission hvior orrsponing to HCHO n osrv in th LTR intrvl. Th gnry of light mission hvior n lso sn in th LTR intrvl in th rgion not s B in Fig.. In orr to xmin this hvior furthr, Fig. shows th rsults of hmil kintis simultion in whih numril lultions wr m of th lmntry rtions. Th onitions us in th simultion wr n ngin sp N = rpm, omprssion rtio ε = :, initil tmprtur T = 7 K n initil prssur P =. MP. Th horizontl xis inits th rnk ngl θ [g.]. Shown from th top long th vrtil xis is th ylinr prssur P (MP), ht rls rt (,

6 J/g.), in-ylinr gs tmprtur (K) n th mol frtions of th OH ril, HCHO, H O, CO ril n CO. Th vrtil xis of th hmil spis grph is givn in logrithmi nottion. Th wvform in Fig. shows two-stg ht rls pttrn ttriutl to low- n high-tmprtur oxition rtions. It is sn in th simultion rsults tht th mol frtion of HCHO inrs grully t th point whr ht rls ws mnifst u to th low-tmprtur oxition rtions. Th numril lultions of th lmntry rtions wr on t zro imnsion n unr n iti onition. Consquntly, th simultion rsults o not urtly rprou th xprimntl t, whih wr influn y th in-ylinr flow of th omustion gs n ht loss. Howvr, us oth sts of rsults r for phnomn inu y low-tmprtur oxition rtions uring th ht rls prio, it is prsum tht th light mission osrv in th tst ngin t wvlngth orrsponing to tht of HCHO ws u to th proution of HCHO. On th othr hn, th OH ril onntrtion is low ompr with tht of HCHO. Th proution of th CO ril tht hrtrizs high-tmprtur oxition rtions riss togthr with th xtintion of HCHO n vntully th rtion pros to th proution of CO. In othr wors, it is ssum tht th shrp ris in light mission intnsity osrv in th wvforms msur xprimntlly with th tst ngin rprsnts th ttion of th ontinuous light mission sptrum of CO-O rition tht ourr in this pross. Expnsion of oprtion rgion Figur shows th ngin oprting rgion for DME-HCCI omustion t vrious omprssion rtios n onstnt ngin sp of rpm. Th knoking rgion init for h omprssion rtio is s on jugmnt of nois rsmling knoking uring ngin oprtion unr tht onition. It ws jug tht th ngin misfir whn th ynmomtr ring ws zro. As th omprssion rtio ws lowr, it ws possil to oprt th tst ngin until rltivly high quivln rtio. Stl oprtion ws possil from n quivln rtio φ of. t h omprssion rtio. In th s of rltivly high omprssion rtio, it ws possil to oprt th ngin with torqu output t n quivln rtio low φ =.. Improvmnt of rnkshft output n thrml ffiiny Figur shows th rnkshft output L msur in rltion to th quivln rtio for ngin oprtion unr DME-HCCI omustion t vrious omprssion rtios ε from 9: to :. Th figur lso shows th rnkshft output msur in rltion to th quivln rtio whn th tst ngin ws oprt unr its rgulr spifitions (Tl ) t omprssion rtio ε of : using isl ful. It is sn tht ruing th omprssion Light Emission Intnsity EOH P [MP] Light Emission Intnsity E OH.... P [MP] - - Crnk Angl, θ [g.] ε N [rpm] φ η [%] T EX [K] T W [K] Fig. Bhvior of light mission intnsity in LTR ( orinry snsitivity ) - - Crnk Angl, θ [g.] ε N[ rpm] φ η [%] T EX [K] T W [K]. 7 7 Fig. Bhvior of light mission intnsity in LTR ( high snsitivity ) P [MP] Mol Frtion T G [K] Prssur Tmprtur.. E- E- E- E- E-7 E- E-9 A B DME-HCCI ε = N-rpm E TDC Crnk Angl, θ[g.] Fig. Rsults of hmil kintis simultion Prssur. nm (OH ril) 9. nm (HCHO) Prssur. nm (OH ril) 9. nm (HCHO) OH HCHO HO CO CO EHCHO E HCHO

7 rtio inrs th rnkshft output. Tht is thought to ttriutl to ly ignition timing (i.., omustion in th viinity of TDC) n highr quivln rtio in th oprl rgion of th ngin. A lowr omprssion rtio n highr quivln rtio m it possil to hiv rnkshft output from DME-HCCI omustion tht pproh th output sn for isl oprtion t lowr quivln rtio. Ruing th omprssion rtio unr DME-HCCI omustion rtr th tim of th pk ylinr prssur to point ftr TDC, thry inrsing rnkshft output n rk thrml ffiiny. In th xprimnts, th highst rk thrml ffiiny ws otin t omprssion rtio ε of : n th highst rnkshft output t ε = :. Th ngin misfir t ε =: n stl omustion oul not mintin. INFLUENCE OF ADDING METHANE Oprtion rgion Th stl oprting rgion otin t omprssion rtio ε of :, : n : is shown in Figs. 7, n 9, rsptivly. Th oprl rgion ws fin s th rgion in whih nithr knoking nor misfiring ourr n th mthn-s quivln rtio φ CH i not x th DME-s quivln rtio φ DME. At omprssion rtios of ε = : n :, msurmnts wr m from φ DME =.. It is sn in Fig. 7 tht th ngin misfir whn too muh mthn ws in th rgion of low quivln rtio t omprssion rtio ε of :. In ths xprimnts, misfir ourr t omustion hmr innr wll tmprtur T W of ºC whn th mount of mthn x mthn-s quivln rtio φ CH of. t onstnt DME-s quivln rtio φ DME of.. It ws possil to stily mor mthn until th DME-s quivln rtio φ DME rh., ut s φ DME inrs yon DME-s Equivln Rtio, φ DME Comprssion Rtio ε =: Misfir Knoking Misfir us y ition of mthn Mthn-s Equivln Rtio, φch Fig. 7 Oprtion rgion ( DME/mthn-HCCI, ε =: ) Equivln Rtio, φ [-] DME-s Equivln Rtio, φ DME..... Misfir Knoking.. Comprssion Rtio, ε [-] Fig. Oprtion rgion ( rpm) Brk Thrml Effiiny, η [%]..... DME-HCCI Equivln Rtio,φ Fig. Brk thrml ffiiny (DME-HCCI n isl) rpm Comprssion Rtio ε =: DME-HCCI rpm Equivln Rtio, φ Fig. ( DME-HCCI n isl ) rpm Comprssion Rtio ε =: ε =: ε =: ε =: ε DME-HCCI =: ε rpm =: ε =: ε =7: ε =: ε =9: Comprssion Rtio ε =: Knoking ε =: ε =: ε =: ε =: ε =: ε =: ε =7: ε =: ε =9: Mthn-s Equivln Rtio, φ CH Fig. Oprtion rgion (DME/mthn-HCCI, ε =:)

8 tht lvl, th llowl rgion for th ition of mthn nrrow. It n lso sn in Figs. 7, n 9 tht th mount of mthn whih oul rltiv to th DME-s quivln rtio rs with highr omprssion rtio. For xmpl, in th s of φ DME =., mthn oul to φ CH =. t omprssion rtio ε of :, ut th llowl φ CH rs to. t ε = : n to. t ε = :. As th omprssion rtio ws inrs, th mount of mthn tht oul in rltion to th sm quntity of DME ws rstrit y th ourrn of knoking. Aition of mthn t onstnt DME-s quivln rtio φ DME Figur -() shows typil xmpls of th wvforms msur whn mthn ws t vrious mthn-s quivln rtios of φ CH =,.,. n. whil kping th DME-s quivln rtio onstnt t φ DME =.. Th tst ngin ws oprt t n ngin sp N of rpm n omprssion rtio ε of :. Figur -() shows n nlrg rprsnttion of th wvforms, n Fig. -() shows th rnkshft output s funtion of φ CH, whih ws inrs in inrmnts of. whil kping φ DME onstnt t.. Th numrs,, n in Fig. -() orrspon to wvform nos.,, n in Fig. -(). It is sn in Fig. -() tht th onst of shrp ris in th ylinr prssur shift to ltr rnk ngl s th mount of mthn ws inrs n tht th pk ylinr prssur ros highr. Th wvforms in Fig. -() init tht oth LTR (lin ) n HTR (lin ) gn t ltr rnk ngl with n inrsing mthn ontnt. Th HTR onst tim θ HS (lin ) in prtiulr ws sustntilly rtr. In ition, th mximum Q Hmx of HTR ros s th mount of mthn ws inrs. This ris in th of HTR is ttriut to n inrs in th injt ht vlu with lrgr mthn ontnt. DME/mthn-HCCI N = rpm φ DME =. : φ CH =. : φ CH =. : φ CH =. : φ CH =. - - TDC Crnk Angl, θ [g.] Fig. () Influn of mthn ition on (ε =:, φ DME =. onstnt). Mthn-s Equivln Rtio, φ h... Light Emission Intnsity DME-s Equivln Rtio, φ DME Comprssion Rtio ε =: Knoking Mthn-s Equivln Rtio, φ CH Fig. 9 Oprtion rgion ( DME/mthn-HCCI, ε =: ) P [MP] E OH Prssur. nm ( OH ril ) 9. nm ( HCHO ) - Crnk Angl, θ [g.] ε Q [J/yl] DME φ DME CH φ CH Fig. () DME / mthn-hcci msur wvforms ( rpm) Output Brk Thrml Effiiny Tim of th Pk Cylinr Prssur ATDC 7 o [g.] DME φdme =. rpm, ε = : Mthn-s Equivln Rtio, φ CH Fig. () DME / mthn-hcci output,rk thrml ffiiny, n tim of th pk ylinr prssur (ε =:, φ DME =. onstnt) ATDC o [g.] ATDC o [g.] ATDC o [g.]

9 Th light mission intnsity wvforms of th intrmit prouts in Fig. -() init tht th onst of shrp ris in light mission intnsity shift to ltr rnk ngl s th mount of mthn ws inrs. Tht is us th onst of th light mission hvior of th intrmit prouts ourr inintl to th ly of th HTR onst tim θ HS. Th inrs in th injt ht vlu with th ition of mor mthn us th light mission intnsity of th intrmit prouts to ris. It is sn in Fig. -() tht th rnkshft output ros s th mthn-s quivln rtio ws inrs. With highr mthn-s quivln rtio, th tim of th pk ylinr prssur ws ly n th injt ht vlu lso inrs, oth of whih prsumly ount for th inrs rnkshft output. Brk thrml ffiiny lso ros with n inrsing mthn-s quivln rtio φ CH, ut th inrs tn to om smllr ftr φ CH x. n thr ws virtully no hng ftr φ CH rh.. At point (φ CH = ) in th rk thrml ffiiny wvform, th pk ylinr prssur ourr t 7º ATDC, ut th tim of th pk ylinr prssur ws rtr to th viinity of º ATDC t point (φ CH =.), n th wvform shows sustntil inrs in rk thrml ffiiny. At point (φ CH =.), th tim of th pk ylinr prssur ws rtr furthr to º ATDC, ut vry littl inrs is sn in rk thrml ffiiny. At point (φ CH =.), th tim of th pk ylinr prssur ws rtr to º ATDC n no inrs in rk thrml ffiiny is osrv. In th intrvl twn points n in th wvform, rk thrml ffiiny inrs sustntilly us th tim of th pk ylinr prssur stily pproh rnk ngl rng of º~º ATDC, whih is thought to n pproprit tim frm for th ylinr prssur to pk. On th othr hn, rk thrml ffiiny shows littl inrs in th intrvl twn points n us th pproprit tim frm for th pk ylinr prssur hs lry n rh. Figur -() shows typil xmpls of th wvforms msur for vrious mthn-s quivln rtios φ CH of,.,. n. whil kping th DME-s quivln rtio onstnt t φ DME =.. Th tst ngin ws oprt t n ngin sp N of rpm n omprssion rtio ε of :. Figur -() shows typil wvforms msur for vrying quivln rtios φ CH of,.,. n. whil kping φ DME onstnt t.. Th tst ngin ws oprt t n ngin sp N of n omprssion rtio ε of :. Figurs -() n -() show th rnkshft output s funtion of. inrss in φ CH whil kping φ DME onstnt t. unr h st of onitions, rsptivly. Looking t th wvforms for ngin oprtion unr DME-HCCI omustion in Figs. -() n -(), it is sn tht LTR n HTR gn t ltr rnk ngl for ε P [MP] P [MP] Prssur - Crnk Angl, θ [g.] ε Q in [J/yl] DME φ DME CH φ CH Fig. ()DME / mthn-hcci msur wvforms ( rpm) 7 Fig. () DME / mthn-hcci output,l [kw] ( rpm, ε =:,φ DME =. = onstnt ) Prssur - Crnk Angl, θ [g.] ε Q [J/yl] DME φ DME CH φ CH Mthn -s Equivln Rtio, φ CH Fig. ()DME / mthn-hcci msur wvforms ( rpm) Mthn-s Equivln Rtio, φ h DME φ =. rpm, ε =: 7 Fig. () DME / mthn-hcci output,l [kw] ( rpm, ε =:,φ DME =. = onstnt ) DME φ=. rpm, ε =

10 = : thn for ε = :. Tht n ttriut to rtring of th LTR n HTR onst tims t th lowr omprssion rtio. It is osrv in th wvforms in h figur tht th onst of LTR n HTR ourr t ltr rnk ngl s th mount of mthn ws inrs. Howvr, th fft of th ition of mthn on rtring LTR n HTR ws smllr t th highr omprssion rtio. In th s of high omprssion rtio, th prssur fils r lrgr, so th rtions wr prsumly mor pnnt on prssur thn on th mthn ontnt. Th wvforms in Figs. -() n -() init tht output inrs with th ition of lrgr mount of mthn. Tht is us th ition of mor mthn inrs th injt ht vlu of th ful. Howvr, whn roughly th sm mount of mthn ws, output ws highr t ε = : thn t ε = :. Th rson for tht is us tim of th pk ylinr prssur t ε = : ws rtr to rnk ngl ftr TDC ompr with tht for TDC for ε = :. Light mission hvior in st HTR n n HTR Figur shows th wvforms msur for vrying mthn-s quivln rtios of φ CH of,.,.,. n. unr onitions of omprssion rtio ε = : n onstnt DME-s quivln rtio φ DME =.. Th wvforms init th ourrn of two-stg HTR s th mthn-s quivln rtio φ CH ws inrs. Th first stg signifis th st HTR n th son stg (rgion B) th n HTR. Th rtion pross of DME/mthn pros from DME-inu LTR rtions prouing HCHO n CO, through DME-inu st HTR rtions prouing CO, to CO n mthn oxition rtions rprsnting th n HTR. In othr wors, th mnifsttion of th n HTR is u to th ition of mthn. Th rsults in th figur lso init th intgrtion of th st n n HTR s rsult of inrsing th mthn-s quivln rtio φ CH. In Fig., wvform- ws msur for ngin oprtion unr DME-HCCI omustion t DME-s quivln rtio φ DME of. n wvform- ws msur for DME/mthn-HCCI omustion whn mthn-s quivln rtio φ CH of. ws to φ DME =.. wvform- shows vin of th ourrn of st n n HTR, n th ounry twn ths rtions is not y th sh lin. Th light mission intnsity wvforms not s wvform- t wvlngths of. (OH ril) n 9. (HCHO) oth show fint light mission hvior in th st HTR intrvl (R rgion), ut ftr pssing th sh lin n ntring th n HTR intrvl (R rgion), shrp ris in light mission intnsity is osrv. It is gnrlly si tht th st HTR rprsnt DME oxition rtions n tht th n HTR r rtions whih onsum mthn. Thrfor, it is Light Emission Intnsity P [MP] EOH EOH H.R.R [J/g.] DME/mthn-HCCI rpm ε = : φ DME =. - st HTR TDC Crnk Angl,θ [g.] st HTR, n HTR Comin n HTR B Mthn-s Equivln Rtio, φ h Fig. Influn of mthn ition on Prssur. nm (O H ril) DME-HCCI. nm (O H ril) DME/Mthn-HCCI 9. nm (H C H O ) DME-HCCI 9. nm (H C H O ) DME/Mthn-HCCI R st HTR n HTR Fig. Light mission intnsity in st HTR n n HTR : DME-HCCI, φ DME =. : DME/mthn-HCCI, φ DME =., φ CH =. prsum tht th light mission hvior sn in th st HTR intrvl is ttriutl to DME-inu oxition rtions n tht sn in th n HTR intrvl n sri to th oxition rtions of CO n mthn. Vrious mixing rtios of DME n mthn unr onstnt injt ht vlu Figur -() shows slt msur rsults in rng of ± J/yl whn th totl ht vlu Q in (= Q DME + Q CH ) of DME n mthn injt pr yl ws st t J/yl. Figur -() is n nlrg rprsnttion of th wvforms, n Fig. -() shows th rnkshft output otin unr h st of onitions. Th lttrs,,, n in Fig. -() orrspon to th wvforms not y th sm lttrs in Fig. -(). R - Crnk Angl, θ [g.] EHCHO EHCHO Light Emission Intnsity

11 Th wvforms in Fig. -() init tht LTR (lin ) n HTR (lin ) gn t ltr rnk ngl s th proportion of th mthn-s quivln rtio ws inrs n tht th HTR urtion simultnously lngthn. In ition, ing too muh mthn us th tst ngin to misfir (plot in Fig. -()). In th s of Q in (= Q DME + Q CH ) = ± J/yl, LTR ourr unr th onitions of (), ut th rtions i not pro to th ourrn of HTR. Th light mission intnsity wvforms of th intrmit prouts in Fig. -() show tht th light mission intnsity gn to ris t ltr rnk ngl s th proportion of th mthn-s quivln rtio ws inrs. Tht is prsumly u to th fft of rtring th HTR onst tim θ HS (s Fig. 7) y th inrs proportion of th mthn-s quivln rtio. In Fig.-(), th figur of h point shows th tim of th pk ylinr prssur. Th rsults in Fig. -() show tht th rnkshft output ros n s th proportion of mthn ws inrs. Th rson for tht is us th inrs proportion of mthn rtr th tim of th pk ylinr prssur, ringing it losr to th optimum tim frm. Light Emission Intnsity P [MP] E OH Prssur. nm (OH ril) 9. nm (HCHO) - Crnk Angl, θ [g.] ε Qin [J/yl] DME φ DME CH φ CH Fig. () DME / mthn-hcci msur wvforms ( Q in = ± [J/yl] onstnt ) E HCHO Rsults for ition of mthn unr rltivly high omprssion rtio Figur -() shows slt msur rsults in rng of ± J/yl whn th totl ht vlu Q in (= Q DME + Q CH ) of DME n mthn injt pr yl uring ngin oprtion unr DME/mthn-HCCI omustion t omprssion rtio ε of : ws st t J/yl. Figur -() shows th rnkshft output msur for h st of onitions. Figur 7-() shows slt msur rsults in rng of ± J/yl whn th totl ht vlu Q in (= Q DME + Q CH ) of DME n mthn injt pr yl uring ngin oprtion unr DME/mthn-HCCI omustion t omprssion rtio ε of : ws st t J/yl. Th rnkshft output otin unr h st of oprting onitions is shown in Fig. 7-(). Th wvforms in Figs. -() n 7-() show tht LTR n HTR gn t ltr rnk ngl s th proportion of th mthn-s quivln rtio φ CH ws inrs. Th HTR onst tim θ HS in prtiulr ws sustntilly rtr n th HTR urtion ws lngthn. It is sn in Figs. -() n 7-() tht th rnkshft output inrs s rsult of rtring th onst tim of LTR n HTR. Tht is ttriut to th ft tht rtring tim of th pk ylinr prssur to th pproprit tim ru th mount of ngtiv work. Ths rsults init tht th onst tim of LTR n HTR n ontroll vn t rltivly high omprssion rtio y justing th proportions of th DME n mthn-s quivln rtios. Howvr, :φ CH =. :φ CH =. DME/mthn-HCCI N = rpm Q in =Q DME +Q CH =± [J/yl] :φ CH =. :φ CH =. - - TDC Crnk Angl, θ [g.] :φ CH = Fig. () Influn of mixing rtios of DME n CH on Injt ht vlu Q in =Q DME +Q CH onstnt Tim of th Pk Cylinr Prssur ATDC o [g.] ATDC o [g.] Q in=q DME+Q CH =± [J/yl] ATDC o [g.] Misfir Fig. () DME / mthn-hcci output,n tim of th pk ylinr prssur ( Q in = ± [J/yl] onstnt ) Mthn-s Equivln Rtio, φ CH ATDC o [g.]..... Mthn-s Equivln Rtio, φ CH

12 in th s of high omprssion rtio, thr r svr rstritions owing to th ourrn of knoking, mong othr ftors, s ws m lr y th oprtion rgion igrms in Figs. n 9. Thrfor, ompr with omprssion rtio ε of :, th onst tim of LTR n HTR must ontroll mor prisly. Crnkshft output otin with DME/mthn ful ln Figurs -() n () rsptivly show th rnkshft output n rk thrml ffiiny otin in rltion to th injt ht vlu unr ngin oprtion on DME/mthn-HCCI omustion t omprssion rtio ε of : whn th proportions of th injt ht vlu Q DME n injt ht vlu Q CH wr vri. For omprison, th figurs lso show th rnkshft output n rk thrml ffiiny otin with th orinry isl ngin spifitions (Tl ) n isl ful s th tst ful. Similrly, Figs. 9-() n () n Figs. -() n () show th orrsponing rsults otin t omprssion rtios of ε = : n :, rsptivly. P [MP] - Crnk Angl, θ [g.] Prssur 7 ε Qin [J/yl] DME φ CH φ ±. ±.. ±.. ±.. ±.. Fig. () DME / mthn-hcci msur wvforms ( Q in = ± [J/yl] onstnt ) For DME/mthn-HCCI omustion, th proportion of mthn Q CH in th totl injt ht vlu ws inrs in inrmnts of %, n th figurs show th rnkshft output otin in rltion to h proportion of mthn. In Fig. -(), it is sn tht th ition of mthn rsult in highr output for DME/mthn-HCCI omustion thn for DME-HCCI omustion. In ition, y justing th mixing rtios of th two typs of ful, th output otin with DME/mthn-HCCI omustion pproh tht of isl ngin oprtion. Figur -() inits tht high rk thrml ffiiny ws mintin. P [MP] Crnk Angl, θ [g.] Prssur..... Q in =Q DME +Q CH =± [J/yl] 7 ε Qin [J/yl] DME φ CH φ ±. ±.. ±.. ±.. ±.. Fig. 7 () DME / mthn-hcci msur wvforms ( Q in = ± [J/yl] onstnt ) Mthn-s Equivln Rtio, φ CH Mthn-s Equivln Rtio, φ CH Fig. () DME / mthn-hcci output,l [kw] ( Q in = ± [J/yl] onstnt ) Q in =Q DME +Q CH =± [J/yl] Fig. 7 () DME / mthn-hcci output,l [kw] ( Q in = ± [J/yl] onstnt ) In Figs. 9- n -() n (), it is sn tht th fft of mthn on improving rnkshft output n rk thrml ffiiny t omprssion rtios ε of : n : ws ivi twn rgion of lrg fft (rgion L) n on of smll fft (rgion S). Ths rsults wr strongly influn y th optimiztion of th ignition timing y th proportions of th DME n mthn-s quivln rtios. This suggsts tht

13 th ttinmnt of high output unr high omprssion rtio rquirs pris justmnt of th mixing rtios of th two typs of ful. In this stuy, th highst output of. kw ws otin unr onitions of omprssion rtio ε of :, DME-s quivln rtio φ DME of. n mthn-s quivln rtio φ CH of.. Th highst thrml ffiiny of.% ws otin unr ngin oprting onitions of omprssion rtio ε of :, DME quivln rtio φ of. n mthn quivln rtio φ of.. Brk Thrml Effiiny, η [%] rpm Comprssion rtio ε =:.... Injt Ht Vlu, Qin [J/yl] Fig. () ε =: ( DME/mthn-HCCI n isl) rpm Comprssion rtio ε =: Injt Ht Vlu, Qin [J/yl] DME/Mthn - HCCI rpm) Comprssion Rtio ε =: Q in =Q DME +Q CH Q CH = [%](DME-HCCI) Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] DME/Mthn - HCCI rpm Comprssion Rtio ε =: Q in =Q DME +Q CH Q CH = [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Fig. () Brk thrml ffiiny, η [%] ε =: ( DME/Mthn-HCCI n isl) Brk Thrml Effiiny, η [%] Brk Thrml Effiiny, η [%] rpm Comprssion rtio ε =: L DME/Mthn - HCCI rpm Q in =Q DME +Q CH Q CH = [%] S Injt Ht Vlu, Qin [J/yl] Fig. 9 () Brk thrml ffiiny, η [%] ε =: (DME/mthn-HCCI n isl). rpm Comprssion rtio ε =: L S Comprssion Rtio ε =: Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] DME/Mthn - HCCI rpm Comprssion Rtio ε =: Q in =Q DME +Q CH Q CH = [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Injt Ht Vlu, Qin [J/yl] Fig. () ε =: (DME/mthn-HCCI n isl) rpm L S Comprssion rtio ε =: Injt Ht Vlu, Qin [J/yl] DME/Mthn - HCCI rpm Comprssion Rtio ε =: Q in =Q DME +Q CH Q CH = [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Fig. () Brk thrml ffiiny, η [%] ε =: (DME/mthn-HCCI n isl) rpm Comprssion rtio ε =: L. S.... Injt Ht Vlu, Qin [J/yl] Fig. 9 () ε =: (DME/mthn-HCCI n isl) DME/Mthn - HCCI rpm Comprssion Rtio ε =: Q in =Q DME +Q CH Q CH = [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ [%] Q CH = ~ ) [%] Q CH = ~ [%] Q CH = ~ [%] CONCLUSIONS Th xprimntl rsults of this stuy m th following points lr with rspt to omprssion rtio hngs: () Th onst tim of low-tmprtur rtions (LTR) n tht of high-tmprtur rtions (HTR) wr furthr ly with lowr omprssion rtio n th LTR urtion m longr. () Th mount of ht rls y LTR inrs s rsult of lowring th omprssion rtio. () Prsumly, th onst tim of HTR ws sustntilly

14 influn y th mount of ht rls uring th LTR urtion. () Whn th injt ht vlu of th ful ws inrs t lowr omprssion rtio, fint light mission orrsponing to HCHO ws osrv uring LTR. () Ruing th omprssion rtio h th fft of rtring th tim of th pk ylinr prssur. Th highst rk thrml ffiiny ws otin t omprssion rtio ε of :. () Ruing th omprssion rtio nl th tst ngin to oprt t rltivly high quivln rtio, n th rnkshft output pproh th lvl otin t low quivln rtio unr orinry isl ngin oprtion. Th xprimntl rsults lso m th following points lr with rspt to two-ful ln: (7) A low omprssion rtio filitt ngin oprtion in th rgion of high injt ht vlu Q in (Q DME + Q CH ). Aitionlly, th rgion llow for th ition of mthn inrsingly nrrow with highr omprssion rtio. () Whn mthn ws unr onition of onstnt DME-s quivln rtio, th highr mthn-s quivln rtio ly th ourrn of LTR n HTR. Furthrmor, th mount of ht rls y HTR inrs. Howvr, inrsing th omprssion rtio ru th fft of th ition of mthn on lying LTR n HTR. (9) Whn mthn ws unr onition of onstnt DME-s quivln rtio, vin of th n HTR ws sn in th ht rls wvform s rsult of th highr mthn-s quivln rtio. Th light mission hvior of th intrmit prouts of th st n n HTR ws osrv y mns of mission sptrosopy. () Unr onition of onstnt injt ht vlu, th onst tim of LTR n tht of HTR wr rtr s th mthn rtio ws inrs. () As th mount of mthn ws inrs unr onition of onstnt injt ht vlu of DME, rk thrml ffiiny ros togthr with th rnkshft output in th intrvl whr th tim of th pk ylinr prssur ws suitly rtr. With furthr inrs in th mthn itiv, th rnkshft output ros us of th rsulting highr injt ht vlu. Brk thrml ffiiny, on th othr hn, i not show ny ppril inrs us th tim of th pk ylinr prssur h lry rh th viinity of suitl ignition timing. () Ajusting th proportions of DME n mthn to n optimum mixing rtio m it possil to ontrol th tim of th pk ylinr prssur, n highr output ws otin thn with DME-HCCI omustion. This inits tht pris justmnt of th mixing rtio is nssry in th s of high omprssion rtio. () At omprssion rtio of ε = :, rltivly high output ws sustin for ngin oprtion unr HCCI omustion. Th rnkshft output ttin pproh tht of th rgulr isl ngin spifitions whn oprt on isl ful. Th HCCI ngin ws l to sustin high rk thrml ffiiny. REFERENCES. Eng, J.A., Lppr, W.R. n Slon, T.M, Th Efft of POx on th Autoignition Chmistry of n-hptn n Isootn in n HCCI Engin, SAE ppr, --.. Tro Aoym, Yoshiki Httori, Junihi Mizut, Ysuo Sto, An Exprimntl Stuy of Prmix-Chrg Comprssion Ignition Gsolin Engin, Proings of JSAE (in Jpns), 977, Vol.7, No., April (99).. Koji Morikw, Mkoto Knko, Jin Itoh, Youhi Sishu, Stuy on Homognous Chrg Comprssion Ignition Gsolin Engin First Rport -Invstigtion of Engin Systm n Rliztion of Comprssion Ignition-, Proings of JSAE (in Jpns), No.-, pp.- ().. Mkoto Knko, Koji Mrikw, Jin Itoh, Youhi Sishu, Stuy on Homognous Chrg Comprssion Ignition Gsolin Engin Son Rport -Control of Auto-Ifnition y MixturStrtifition-, Proings of JSAE (in Jpns), No.-, pp.9- ().. Koji Hiry, Akihiko Kkuhou, Tomonori Urushihr, Truyuki Itoh, A Stuy of Gsolin Ful Comprssion Ignition Engin -Efft of Ful Rformtion uring Ngtiv Vlv Ovrlp-, Proings of JSAE (in Jpns), No.7-, pp.-, (), ().. Irvin Glssmn, Comustion Thir Eition, pp.9 n pp.9 7. Ttsuy IGARASHI, Norims IIDA, Stuy of Auto Ignition n Comustion in Homognous Chrg Comprssion Ignition Engin, Proings of Th th Intrnl Comustion Engin Symposium, pp.77-, Sptmr, Jpn, (997).. M. J. Pilling, Low-Tmprtur Comustion n Autoignition, Vol., Introution XII-XVI, pp. IX-XVII 9. Mitsuru Konno, Comprssion ignition mhnism of mthn, Proings of th Mhnil

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