傳熱學(xué)楊世銘答案

經(jīng)典word整理文檔，僅參考，雙擊此處可刪除頁眉頁腳。本資料屬于網(wǎng)絡(luò)整理，如有侵權(quán)，請聯(lián)系刪除，謝謝！11110.0031tq＝w42400tqn2xgradtq,q/(.K)W/(.K)W/(.K)45W及2xyijkW/(m2.K)W/(m2.K)qqiqjqk,,及xyz34tt30(2)A37.2120時，)11tfw110.0007940.1520.00951231hh11.52.5450.070.1t＝30時())212fx＝＝w2t()h(tt)/(.)WmKW/(.K)xwwf575055tt1q150020.020122211.30.12m268A及BAB0.1W/(.K)0.06W/(.K)tB,f1Ah1WmK50/(.)tWm2K9.5/(.)f2h。29ttqhtthttf1fw1f12f2ABBtAxy又fwAB0.078;0.039mmABW/m26。tf180℃，冷表面溫度t230mmt1t,t12thtttttt1803.7210/(.);WmK8得t12crt,1t,2t,1t,21t3022.6710W/(.K);2cmcm2tt18030d2A214W/(.K)。ffttttq1q5200w/m2121f12f123＝tt1231AQAq41.95W12122q2q1f1得fgairttgio28.1%ff·為fkg/m3-42℃0.0330.0023tW/(.K)740W/(m2.K)2ddt30ttW/(.K)12112t600lqf0.06W/(.K)dds107mm122qKt得/(.)WmK60300.0010.06q60301800W/m21lttWm1142.8/q21210.2lndd/lndd/3Z1213220.02qqqZ2942.8/Wm2168.25WZ℃/(.)WmK為ltt172.33W12lndd/121ttltt121219.195075507575ltt2lnln358.29W12505075lndd/322ll12lttltt10導(dǎo)熱系數(shù)為W12z1212ln2.5ln1.615.47/(.K)321ttq2ltt)101QqW12122r/r)/1.5121119.86IR22IA1AW/(.K)100W/(m2.K)/(.)WmK10m/m10m/m3333B5000W/(m2.K)/(.K)W()0.03120)100）rlhtth＝12/(.)WmK）；/(.)222WmK0.0350.049(r0.015)3.14(rr)4r3rm）1。23，m11212ltt)110002001212532.98W1ln(/)rr11ln52/401ltt2112150000.02420.026100rrln/rrln/1rh11hr2210211ltt)hr2212rrrr100201ln(/)ln(/)176.11022ln0.035/0.015ln0.049/0.03511hr10hr02260.049110002005852.94W②1ln54/52ln52/4010.03871(r0.015)4(rr)3.142r1m222330.0250000.08420.027100，⑵⑶121r0.0492lttltt)1rr2112lnr/rlnr/r11ln(/)ln(/)ln/rr1rri1021022111hrhr10hr2i220i100201100020043.725207.06Wln0.03871/0.015ln0.049/0.0387111ln54/52ln52/40ln40/3610.10.513.260.04950000.0180.084211000.027W/(.K)dl1.8104/(.)WmK25(195.6)〕ttdx)d1.8100.822W4td224x111x4x4－2，210.150.165t200.822243600199.61000xttxt1xl,ttm0.3562Kgx2tt12t2W/(.K)l1/(.)tt()3f2330Wm2K②1t4h2tt)0txttxl,ttt1x2f212R111hh(2)x(2)xttCeCe11111ddR()()0.1785f12rr0.11.011.330hr2212(40)hh448.168W)tt)e2e2dltt)tt)ttldhhxtte2xe22f1f1f2fddWfhhhhe2le2le2le2dldddd0.15m;d0.25m,t200長10W/(m2.K)i0t/(.K)W。40t0tttt)eetttttmlml～。[emxe]mx2f1f1f2fxemlemlemleml20040〕h456.5Wm2mlm211d－＝0.150.25W/(.K)t(6030)(25030)e2.12e(25030)(6030)2.12|7.07[xx0ee2.12ee210W/m53tdW/(m.K)td222(19.46WfQ440－tt)ettettttml434tmlr65416|[emle]V332f1emlemlf1f2fml3xtemlemlxl(6030)(25030)e2.12e(25030)(6030)2.120.0654161056541.67W|7.07[e－2.12e2.12xxle2.12e2.12e2.12e2.12(25)6541.67rht2d42〔t30.78〕Q162.89)2.05W15.24W解得t53.62℃xl11－0.250.3/(.K)Wm1/2m1/2x25,x125mmr0.5m,l2.0mW/(m2.K)。0。12ttt12x2A1dxxn84℃。f0xx2n1320m22x211111Aax2＝1R1XhAhArridx4tx2ioo112x2x320.35m21Aax2＝W11X162024Rdxox4dx263.23mxx2221A2xxW＝11X3o31211111111RthAhA4rr1rr2iioo1223bt)W0tRobb1W3oWmK5/(.)W/(.K)得21W/(m2.K)Abt)又0ttxx1b1tt2/(.K)A210122120W）ttt422b0212tt22t1）02100W/(.K)()bt)trrttrrttt處，處。20。112(x)x30ddtr0rcxrdrdr001x51.23即4.16.5x得0b6.54.11ccrclntt202001012即rr0.410.082dxx得xbln1397Wt01tcrc20rrtt21112處即1）1d,t,tlncrct02t02xdaxna及nrtt112r22122處即2）2b2xtt1tt12012012221c2lnrr112x21bx1lnttttr20120121111/2xct(x)212221lnrr2bb120brlncttt1t22212112rt(x)t012021）2b1bc,c0將12tt=λ120rrbbt1tt12tttt222x012r100012r2qbtt1ttddt2c012012Axxx0q1rdxdxrr.ln1r2得()bt)及t式0t1rrrr0()bt)ttxx=0mm,10mm,20mm0rtcrcr212)brr,tt;r0,tt0。0w010060t802ttr/ttr/℃33r3tlnrt0w00w0ln1lnr1r0qtt)b0012又即01b1006010000）-41b60401000。00.02）0.6870()bt)t0d()r(r)0t(x0),t(x)12dtdtr，；rrh(tt。dr0drfatt1e1rhtt。xln12faat0r2tcrc00由，c1；e412ax0ax是rdtr2(，得htthct0rrdr242ff由，，0rr204rc20t02h2hf。dt20m2/mW2）/(.K)/I2b2A2C0(r))rrtt00處0rr,tt001txtrrrr01teeaaa220001te1trr,ttaaa22tt20000當tqrr4Arrt223310dt1000qedxat,tf10及及f2hh,ttf112f210W/m63450W/(m2.K)18W/(.K)1ddt10rrdrdreax0；1a處處1ddt20rrdrdrtrt為有限；。d2t10e1又處處20dtdtrr時，tt,11dr2112dt2dr。dt1drdte,rtrtt,1a2tt0021212dre對；22ax12aatxt00a2a1rr時，htt222dr21。0令A(yù)QmthmHr2Wc0tclnrc；1r121HH2,66.9Wtcrc2cccc121212t為有限的條件，得c0據(jù)11rrc2200rrccrctwtf11142r1211212111；/(.)Wm2K/212.9;1.03105mcHHmmAA2rrhcrct12f22r1222382，22(H)0.313h1/2rrc，ctlnr2A11222hr12f22222r12.5;rrH25.4rrrr222121c2lnt0.88111242hr2r1ff。1222rrhtt37.15Wrrrrr22222lnt021wft11111442hr2r1f.7W；11220frr221tt2lnrlnr12httrsWn;122hrf21swf。222n4382.8WZ208/(.)WmK/(.)WmK2/(.)WmK/(.)WmK2W/(.K)/(.)WmK20.6%1chmh0.6100,2hchmhHh0h0mharcch5.81105，thhU5.8191.3%m48.75H0.119mf48.7549.10.9103。2hHh=25W/(m2.K)th56.9%390W/(.K)50W/(.K)。ftf/(.)h=15Wm2K度28W/(m2.K)/(.)WmKd2t0hp/A14.092m）ttcsAA又ccmxmemHmhcemH0he20mmh2tt510mH,22mxmheemHmheemxmH00℃0202時mHmHemhemh221℃22mHxhmmHx2hm020mmHxmmHxmhd2|AchmHhm0x002xhmAm2Wmh0x0m02為··3為didd·of為a所bttt12W/(.K)0H2lS8.156mmHxh/mmHxbttln1.082tt0h/md2SttW/m12cece,c、c由邊界條件確定：，1212x，ccxHcc，2，hcecemHmHmHmH/(.)WmK011212emHmht,t,tc102mhemhemHmH，22＝st0.80.15x40050035012.6W。213dd4w4wdd4w4w22222tttlRln1212/2l1l2l321dd1dd2為212bRln1.08/l2dA,A,2121t,t1/2）/;RARA）））111222RRR`112AARR121122ttAAtQ211122RmmmmW/(.K),。0irr1R;R21rrhii2i1irr1R;R32rrh0020200.752x0.52x0.752x0.52x1010mmmm0.75x220.540.752x210m.K/Wxxx42S0.752xh=150W/(m.K)2220.540.52x40.15x20.752x0.52x20.752xx2600W/(.K)10W/m又42Stt12℃xmhAtt1r,rtt21A4tt1112trr2＝2121R11r1r1h，。1226,;1.510/4wm2QqAQqt12tRStt又12122Rq,t,r,rJJJm38.9Wm33m3600s102.8ms532，Wrs22338.90.04mRm3t℃s℃℃℃5.09℃r35mm,r48mm15W/(.K)h36WmK2，，23＝dlqRR38.90.04℃21r℃5.090.025.11℃tltttth660.50。1s2s1rrddrr1r1rr，122,,ccctt/ttccxcxln3232ttdq1rr12121123dqs2ttr3x()ttdqlnrr/2r41r22即，s。s11r232tt2qWm1s262d2tdrr0.005lnr0，1322tts1s2tt/ttccxcxqdqWm423rrL1r121123。32xtt;x,tt又21tt840kg/m3/(.)WmKxh=6W/(m2.K)062020x2131t0W/m3r2rrr2W/(m2.K)。ddtrdtrc13rr/1d22r2c1，dtddtrrdrdrrrdrdr33drr2，，drdr，cr212tcr2rcrc6rr，1r，trc1c242122tr，；rRr。httR42R42。。r，c；r，tt，tc，ct122www，rrRRrr22222/hctttt364442wR0.0222rrttt1.35℃2RRh/ct2440.420wct。及與362h2，R22trRrt22h6m，RhRR2tsht0th6rR。t42R∞RRhtt32tst23hs，1003510110.0021l25001.133901.07504.0944.84.88qhTT)1hrad,T4,TT3TT()/2122avav121240WmT470K463。2500Wm2(t)bt)0bW(mK)]mmx1,1qbt200，0t11h～0221qtt023000W/(m2.K)1228822d12mm,d36mmt35h2/(m.K)，i50W，i002btbt222390W/(.K)。qt212t0214H1522ttt2t(a)bt表達式代入：213.14820282bt222bt22bt2bt2tttt2h0101321222mHH212，A，c2th50Wm2K,390WmKb02，t/2tt2t1t22。AH0.0010.018711.871105m212120，ABL2501001053mH0.018712.5591032,/(.K)tt200W3901.871105729，AB101010