(完整word版)传热学答案+第五版+章熙民(完整版)

10．Rt

Rt118.33102m2RA

qi 解:q1t1＝1180.3610)145.92Wm2 h1h2 870.61124 twtfq1037.549.7℃ 0.27.407104KAHL453245

qt285150310330.4KWm2R4.44410t285150103182.3KW iii 解:q1.2c1.2(1)(2)3.96(27350)4(27320)4139.2Wm2tw4tw4100

100

c1.2(1)4(2)3.96(273200)4(27320)41690.3Wm2t'w tw4100即：k11＝111031

h1h2 ' 0.620.650.016R"232560.265m2k/W'230.650.024 （2）由dt2v0tar2t

r2rr （2）由qdt知，q与平壁的材料即物性有关rrr r1r2r2r1 12

12312

123123

13

RRR Rtw1tw4 Rtw1tw4 Rtw1tw46006014.已 tf tf q0101

131031

h10h275 1)k11111

121031

h11h275 2)k2111

2

13101h12h275 3）k31110'

131031

h10h A1B1C1

A2B2C3 115.0410(mk)/WR1R2

0.13070.221

2)ql： 3)tw2,tw3.1231)R11lnd2

21d12581601lnd222

R31lnd22223

t 30050314.1W/mRRR0.5170.279 17.已知:12,211,d2m2d1mR1lnd0211lnd02122

1lnd0211lnd02122

qlt,ql't' 1lnd0211lnd02122ql'R22d0221dd02212'qlR

1ln0

1ln01

1dd022d021ln0

1ln0d41qlR'

231.277qlR1ln3ln5'qlImaxRl1w1maxdtw222.22103120.5123.7(A)lln

1lnd21lnd222

21d122 l

qlt1lnd222Qtw3tw1

F1tw2

R(11-r2)4r

1(1

)1(11

411d1(d2)42(d2)(11)1(11)16.30.350.3560.030.3560.416 1(11)42r2r3

0.3560.416 hUlh2Ll2hl0.025

LmL hUlhdlhl0.12

27.已知:3mm,l16mm hUlh2Ll2hl16103

hUlh2Ll2hl16103

21250.73 lcr2c722.15r133.5 l2l1twtwd

qlQst2tln21.5 l2

l1

Ql1l24l1H

Qt t1

t3

tcRct

t1

t32Rc3 ttf1%0t0tf

hVhR950.5103BivF3

eBi

pln h303103BiV2lnVln haF0hpln22

hVhR83.220103由BivF2

Bi10Bi1,mA0.5mBhAAaAAaBBA2122248minBBBi1

8010.52.6tft000平板查图有：tmtf0 由Rex得x10.1m〈Rec均为层流 Relul0.30.92.98105Recmax4.64l3y

1(y)3uul(y)(2max

2max 由Reccxc 0.6642.86510100.8）20.6971318已知：uyu

式左du(uu)dydu2u(1u)dydu2y(1y)dydx0

dx0

d(u)dxd(U)uUdx dvd6vdx 两边积分有：dx6vdx126x 12xRe12，Rex twtfdy

twtfdy 8ms 5012.31106有：Re111Re2u2l28.0852.31106

22Nu12l11而：11l222l1Q11l2F1t13.81013.091025314030） vavb,papb再：umG

Fd2Reavaumada2db2da2db1Rebumbdbumbdb da2db umbGbda2Gada168Gbdb3015

Gbda2db ln''mG,RefumdG

f f't80340.628130W/(m2K)0.627.871040.14ud q(tt)0.027Re0.8Prf30.81f0.14fPrf3

w

而：Refmi0.114167.2105104ud

t'90202，即t1(tt)30C40C有：''

t9040

2f1f2 PrRR110.3Nuf0.023(2.5310)(5.42)40.8

0.012tf1dnD(twtf)tf14nD(twtf)fumd2CpfQt d2uCpfm

ud 有:RefmtQQ

Fdl0.162.52013 12

t'f2tf1F(twtf)知：fl1Pfum2

5.5421133.32985.61.320.0192

若为光滑量，则有：Refm1.30.01964.78104104udd23T0.45Nuf0.0214(Re0.8100)Pr0.41flTwd23T0.45(Re0.8100)Pr0.41flTw25知：Refm3.50.02264.11103，过渡流ud

d23T0.450.0214(Re0.8100)Pr0.41f15.78W/(m2K)lTwRefumde4102.462.4104104 ud 有：Refm,um'Re0.8Prf330W/(m2K)Q70.82CQ159.5C有：Ref30.01468.12104ud 0.26Re0.6Pr0.37 19.4kW/(m2K)33.已知:d12mm,u14m/s,tf30.1C,tw12CRefud140.01261.05104有：Refmax15.50.0191.96104ud

0.027Re0.63Pr0.36

有：Refmax4.870.0199.23104udPrwS2z0.35Re0.6Pr0.36

PrwS2zud 有:RefmaxNuf0.31Re0.6z 0.31Re0.6zgm2tdPrm41.已知:d50mm,h0.5m,tw90C,tf20C故有:GrPrg2thPrm故有:GrPrgtdPrm9.310713.011031Kgmtd3Pr2107 m13.4251031K gmtl3Pr

56.已知:h2.5m,tw30C,tF10C0.10.1(27320)106.略7.略

14m

解：11 再：12 22 (3）由

而:2 G(0~6)dG(6~10)dG(10~12)d tf100 100 EbEb 100EbEb

1q1、2 1128.17 111

1212

0.80.5

Z(12),3Z1,3Z2,3c=a+b-2aZa,babab2abcos）10.（1）ZdF,FZdF,FZdF,FZdF,F 图9-19）得 (2）Z1,aZ1,(abcd)Z1,(bc)Z1,(cd)Z1,c (llac)(ladlbc)(3）Z1,2Zab,cdbd即:Z2,12Z1,2 图9-20）得 （2）Z1,33(Z3,(12),Z3,2)即：Z1,41(F(12)Z(12),4F1Z1,4aF2c) 1d1p,Z查图即得（P图9-20）dFdpFpd,p Fd1

Fd

dd,3FpZp,3FdZd,p

1dQ,JE1pQdFdd,pP

pFpp,d

EbdJdJpJdJ3J10

1(EdbJdJpJd)FdZd,31d即：cbT34J3,T3(3)14ZF11

J3F2EbEb13F1Z1,2(Eb1Eb2)

30,即：EJEbEb113F1Z1,3(EbEb)

EbEb

13F2Z2,3(Eb2Eb3)EbEb

111F'd2

1F1F1Z

1F1F' 故：Q

EbEb12

2F2F'Z111F'Eb50.5w

1F1F'ZF11

'

'

q1,21112 EbEb 1113a 13b12 即：EbEb EbEb 13b12Eb1(EbEb)111

21

再q1',2q1,3aq3b,2 EEq1',21b11b3 1 33',Z1,31,Z1

'ZF11

(ll)(ladlbc)解：Z1,2acbd

EbEb 112l

1F1F1Z1,22F2(EE)1b11b2dd1(1)112 d1(EbEb)1(11)d112 （3)ql'qlRqlc' '' 1(EE)t EbEb2(tft)11'

12

1(tft1)1(EbEb) EbEb1212.12kwF1F1Z1,2F2(GrPr)mgmt