MODELLING OF THE HEAT LOAD IN THE PISTON OF TURBO DIESEL ENGINE - CONTINUATION

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1 TRANSPORT PROBLEMS 007 PROBLEMY TRANSPORTU Tom Zeszyt 4 Potr GUSTOF*, Aleksander HORNIK, Daman JĘDRUSIK Slesan Unversty of Technology, Faculty of Transort, Deartment of Vehcle Servce Krasńskego St. 8, Katowce, Poland *Corresondng author. E-mal: otr.gustof@olsl.l MODELLING OF THE HEAT LOAD IN THE PISTON OF TURBO DIESEL ENGINE - CONTINUATION Summary. In ths study the mathematcal descrton of characterstc surfaces of the heat exchange of the ston and temerature dstrbuton of the turbo desel engne at the begnnng hase ts work was resented. The comutatons were erformed by means of the two-zone combuston model, the boundary condtons of III knd and the fnte elements method (MES) by usng of COSMOS/M rogram. MODELOWANIE OBCIĄśEŃ CIEPLNYCH TŁOKA DOŁADOWANEGO SILNIKA ZS - KONTYNUACJA Streszczene. W nnejszej racy rzedstawono matematyczny os charakterystycznych owerzchn wymany ceła tłoka oraz rozkład ch temeratury dla doładowanego slnka z załonem samoczynnym w oczątkowej faze jego racy. Oblczena numeryczne zostały rzerowadzone rzy zastosowanu dwustrefowego modelu rocesu salana [], warunków brzegowych III rodzaju oraz metody elementów skończonych (MES) za omocą rogramu COSMOS/M.. MODELLING OF THE HEAT LOAD IN THE PISTON In analysng the engne ston 6 characterstc surfaces of the heat exchange (fg.) were dstngushed whch defnte the values of the boundary condtons of III knd were attrbuted [,3,4]. Fg.. Surfaces of the heat exchange of the ston Rys.. Powerzchne wymany ceła tłoka Surface: ston head, flank ston over I rng, 3 uer groove of I rng, 4 bottom groove of I rng 5 under groove of I rng, 6 between rngs I-II, 7 uer groove of II rng, 8 bottom groove of II rng, 9 under groove of II rng, 0 between rngs II-III, uer groove of III rng bottom groove of III rng 3 under groove of III rng, 4 leadng of the ston,, 5 nternal of the ston, 6 the ont of contact of the ston n wth the engne ston

2 8 P. Gustof, A. Hornk, D. Jędrusk.. Surface of the ston head In calculatons the whole surface of the ston head was acceted for equvalent heat condtons n combuston chamber engne for ndvdual cycles ts work: W ( ϕ ) = g ( ϕ ) m K () ( ϕ ) = T( ϕ ) [ K] T () where: g ( ϕ ) - coeffcent of surface flm conductance n crank angle functon, ( ) of engne workng medum n crank angle functon... Surface sde of the ston over I rng T ϕ - temerature [5]: However for sde surface of ston the followng condtons of the heat exchange were acceted W ( ϕ ) = g ( ϕ ) m K (3) ( ϕ ) 0, 8T ( ϕ ) [ K] T = (4).3 Uer surface of the groove of I, II, III rng In case of uer surface of groove of I, II, III rng (3,7,) the average substtute overall heattransfer coeffcent as well as temerature T ( ) z(3,7,) 3,7, ϕ of medum surroundng the analyzed surfaces was acceted by work []: z = ( 3,7,) d ( 3,7,) lsr tu ( ϕ ) = T ( ϕ ) [ K] m W K T3,7, x (6) where: z( 3,7,) - average substtute overall heattransfer coeffcent n lace of the contact of rng from uer surface of the groove, d ( 3,7,) - average coeffcent of surface flm conductance n lace of the contact of rng from uer surface of the groove, tu - average coeffcent of surface flm conductance n the lace of contact of the rng from the cylnder lner of the engne [6], l sr - the average road of the heat stream from the surface of the groove of the rng to the cylnder lner, - coeffcent thermal conductance of the rng, Tx ( ϕ ) - temerature of the nternal surface of the cylnder lner reresented the ndvdual ostons of the ston n functon of crank angle engne..4. Bottom surfaces of the groove of I, II, III rng In regard to the ga among nternal surface of I, II, III rng and the surface of the bottom of the groove (4,8,) the heat exchange s very low on these surfaces. In calculatons was assumed the fault of heat exchange from these surfaces (adabate) []. (5)

3 Modellng of the heat load n the ston 83 W 4 = 8 = = 0 m K (7) ( ϕ ) = T ( ϕ ) [ K] T4,8, x (8).5. Under surfaces of the groove of I, II, III rng For under surface of the groove of I, II, III rng (5, 9, 3) the average substtute overall heattransfer coeffcent and temerature T ( ) z(5,9,3) 5,9,3 ϕ of medum surroundng the analyzed surfaces was acceted by work []: lsr m K = (9) z( 5,9,3) d ( 5,9,3) tu W ( ϕ ) = T ( ϕ ) [ K] T5,9,3 x (0) where: z( 5,9,3) - average substtute overall heattransfer coeffcent n the lace of contact of the rng from under surface of the groove, d ( 3,7,) - average coeffcent of surface flm conductance n the lace of contact of the rng from under surface of the groove..6. Flank surfaces between rngs of the ston For the flank surfaces between rngs of the ston (6,0) as well as the leadng surface (4) the coeffcent of surface flm conductance ( ϕ ) and ndvdual temeratures of medum 6,0,4 surroundng the analyzed surfaces was descrbed as follows [6,7]:.7. Internal surface of the ston ( ϕ ) W 6,0,4 ( ϕ ) = 3 m K () ( ) 0, T ( ϕ ) [ K] T6 ϕ = 665 () T ( ) 0, T ( ϕ ) [ K] = (3) 0 ϕ 69 [ K] T4 = 348 (4) However for nternal surface of the ston followng averages condtons of the heat exchange were acceted []: W 5 = ( 60 90) m K (5) T = K (6) ( ) [ ] 5.8. Surface of ont of contact of the ston n wth the engne ston In case of the heat exchange of surface ont of contact the n from the ston the boundary condtons 6 and T 6 were descrbed by means of the followng equatons []:

4 84 P. Gustof, A. Hornk, D. Jędrusk 6 = ts l st sw l sk sw s k s sk k 5 m W K (7) ( 333 ) [ K] T = 363 (8) 6 where: = = - average coeffcent of surface flm conductance n lace of contact the ts s k ston- ston n, the ston n bearng bush, the bearng bush connectng rod,,, - heat conductvty of the ston n, the bearng bush and the connectng rod materal, wall of the bearng bush of the ston n and the head connectng rod. sw k S, S - thckness of k. THE RESULT OF COMPUTATION In ths work the heat loads of the ston of turbo desel engne wth drect njecton about caacty 390 cm 3 and ower ratng 85 kw were ntroduced. The comutatons were executed for excess ar rato =,66 and seed of engne n = 000 mn - makng the vsualzaton of the dstrbuton of temeratures on the ston surfaces to 5 degree crank angle after nner dead centre n fllng u ts cycle. The examles results of numerc calculatons for 9 and 8 seconds of the work of analyzed engne were ntroduced on fgure. HEATING UP OF THE PISTON T[K] TIME [s] TIME 8 [s] T[K] Fg.. Phases heatng u of the ston Rys.. Fazy nagrzewana sę tłoka Next the executed numerc comutatons wll become verfed on the secally to ths am reared the engne whch wll allow to make the comlex research on the measurement staton (fg.3).

5 Modellng of the heat load n the ston 85 ar flter Intercooler exhaust system comuter PC engne coolng system ENGINE control system fuel system eddy-current dynamometer measurements system -engne ower -engne torque temerature sensor engne controls baterry sensors -engne seed -boost -temerature: ol; coolng agent; exhaust gas; ar of suerchargng -combuston ar factor valves-seat -thermoelement valves -yrometry cylnder lner -thermoelement ston -thermoelement measurng transducer Fg. 3. Block dagram of measurng oston Rys. 3. Schemat blokowy stanowska omarowego 3. CONCLUSIONS The carred out relmnary calculaton wll suggest that n ntal hase of the work of turbo desel engne the lace of the occurrence of the largest of the heat load of the ston s ts the head as well as the flank surface above the frst rng of the engne ston. The relmnary numerc comutatons show after 8 seconds of the engne work on the heat transfer from these surfaces nto nsde of the engne ston materal. The conducted analyss doesn't ermt fully to qualfy the heat load of ths engne element n regard to short tme, the carred out comutatons however gve any cture of the temerature dstrbuton on ts ndvdual surfaces. Moreover the correctness of conducted calculatons requres on the real ston of the turbo desel engne use of the verfyng researches whch wll be the object of far morer nvestgatons of the authors. Lterature. Gustof P.: Wyznaczane rzebegu temeratur ładunku dla ełnego cyklu roboczego w cylndrze doładowanego slnka o załone samoczynnym. Zeszyty Naukowe Poltechnk Śląskej, Sera: Transort z. 43, Glwce 00.. Kwaśnowsk S., Sroka Z., Zabłock W.: Modelowane obcąŝeń celnych w elementach slnków salnowych. Ofcyna Wydawncza Poltechnk Wrocławskej, Wrocław Wśnewsk S.: Wymana ceła. Państwowe Wydawnctwo Naukowe Warszawa Jaskólsk J.: Zagadnena otymalzacj obcąŝeń celnych tłoków slnków salnowych. Wydawnctwo Poltechnk Częstochowskej, Częstochowa Sygnewcz I, Leyko J., Wajand J.A. n.: Zwększene srawnośc mechancznej slnków salnowych rzez otymalzacje wsółracy zesołu tłok cylnder - erścene tłokowe. Model uszczelnena tłoka. Oracowane Poltechnka Łódzka, Łódź, Wśnewsk S.: ObcąŜena celne slnków tłokowych. Warszawa, WKŁ,97.

6 86 P. Gustof, A. Hornk, D. Jędrusk 7. Parczewsk K.: Metoda dośwadczalno-analtyczna wyznaczana wsółczynnków rzejmowana ceła rzez ścank kanałów chłodzących slnków salnowych. Motoryzacyjny Kwartalnk Naukowo-Technczny, Auto-TM /9, Warszawa, 99. Praca wykonana w ramach badań własnych: BW-488/RT/007 Receved ; acceted n revsed form

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