A HEAT TRANSFER TEXTBOOK - THIRD EDITION Episode 3 Part 1 potx

... [5.6] 13 . Isothermal ellipsoid of semimajor axis b and semiminor axes a conducts heat into an infinite medium at T ∞ ; b> ;a( see 4) 4πb  1 a 2  b 2 tanh 1   1 a 2  b 2  meter [5 .16 ] 24 6 26 2 ... 5 .1 0a Φ 1 ( Fo 1 = 0.565, Bi 1 = 0 . 21 05 ) = 0 .10 Φ 2 ( Fo 2 = 0.565, Bi 2 = 0 . 21 05 ) = 0 .10 and, with eqn. (5.7 3a) , Φ = Φ 1 +Φ 2 (...

Ngày tải lên: 07/08/2014, 10:20

...  = 3 20 φ− 3 28 0 φ 3    = 3 2u ∞ (6. 52) Since φ is a constant for any Pr [recall eqn. (6.46)], we separate variables: 2 t dδ t dx = dδ 2 t dx = 3 /u ∞  3 20 φ − 3 28 0 φ 3  §6.5 Heat transfer ... 0.0 021 35 so τ yx = (0.0 021 35 ) 1 2 ρu 2 ∞ = (0.0 021 35 )(1.05)(15) 2 2 = 0 .25 22 kg/m·s 2 and the force is τ yx A = 0 .25 22( 0.5) 2 =...

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... transitional value. Problems 335 6.31 A thin metal sheet separates air at 44 ◦ C, flowing at 48 m/s, from water at 4 ◦ C, flowing at 0.2m/s. Both fluids start at a leading edge and move in the same ... at 25 ◦ C flows at 0.7m/s over a 4 cm-long flat heater at 60 ◦ C. Find h, τ w , h(x = 0. 04 m), and δ(x = 0. 04 m). 6 .20 A large plate is at rest in water at 15 ◦ C. The plate i...

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... R -1 2 5 1. 10 R -1 2 1. 50 R- 13 4a 1. 63 R-22 2.20 R -1 5 2a 1. 10 R -3 2 1. 20 R- 41 0a 1. 72 so that h fb h lo = fn ( Bo, Co ) (9.49) When the convection number is large (Co  1) , as for low quality, nucleate boiling ... 30 5.6kg/m 2 s and Re lo = GD à f = (30 5.6)(0.05) 1. 297 × 10 −4 = 1. 178 × 10 5 From eqns. (7.42) and (7. 43) : f = 1  1. 82 log 10 (1. 178...

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... Int. J. Heat Mass Transfer, 13: 1 425 –1 439 , 1970. [9. 23 ] J. S. Ded and J. H. Lienhard. The peak pool boiling heat flux from a sphere. AIChE J., 18 (2) :33 7 34 2, 19 72. [9 .24 ] A. L. Bromley. Heat transfer ... correlation for saturated two-phase flow boiling heat transfer inside horizontal and vertical tubes. J. Heat Transfer, 1 12( 1) :21 9 22 8, 1990. §10 .3 Radi...

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... §10.4 Heat transfer among gray bodies 5 53 Additional two-body exchange problems Radiation shields. A radiation shield is a surface, usually of high re- flectance, that is placed between a high-temperature ... equa- tions above. Figure 10.16 Illustration for Example 10.9. §10.4 Heat transfer among gray bodies 549 10.4 Heat transfer among gray bodies Electrical analogy for g...

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... The geometrical mean beam length is defined as L 0 ≡ 4 (volume of gas) boundary area that is irradiated (10. 54) Thus, for two infinite parallel plates a distance  apart, L 0 = 4A / 2A = 2. Some other values ... net heat transfer is calculated using the surface area of the wall: Q net g-w = A w g T 4 g g T 4 w = (0 .4) (5.67 ì 10 8 ) (0.098)( 14 73) 4 (0.12)(5 73) 4...

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... 1.42ì10 5 air-ethanol 31 3 1. 45 air-helium 276 6.24 air-napthalene 30 3 0.86 air-water 31 3 2.88 argon-helium 2 95 8 .3 628 32 .1 1068 81.0 (dilute solute, 1 )-( liquid solvent, 2) T (K) D 12 (m 2 /s) ethanol-benzene ... D 12 (m 2 /s) ethanol-benzene 288 2. 25 10 9 benzene-ethanol 298 1.81 water-ethanol 298 1.24 carbon dioxide-water 298 2.00 ethanol-water 288 1.00 methane-water 2...

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... 59.72.0 16 Air 3. 711 78 .62 8. 96 H 2 O2 .65 5 a 36 3 a 18.02 Ar 3. 542 93. 339 .95 H 2 O2 .64 1 b 809.1 b Br 2 4.2 96 507.9 159.8H 2 O 2 4.1 96 289 .33 4.01 C3 .38 5 30 .61 2.01 H 2 S3 .6 23 301. 134 .08 CCl 2 F 2 5.25 2 53 ... 28.85 Cyclohexane 0.117 33 . 03 n-Heptane 0.1 63 31 .69 n-Octane 0.185 34 .14 n-Nonane 0.207 36 . 53 n-Decane 0.229 39 .33 Acetone 0.074 28.9...

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... possi- bilities in turn. Heat transfer at low rates of mass transfer One very common case of low-rate heat and mass transfer is the evapora- tion of water into air at low or moderate temperatures. ... mass transfer. Coupling can arise when temperature-dependent mass transfer pro- cesses cause heat to be released or absorbed at a surface. For example, during evaporation, late...

Ngày tải lên: 07/08/2014, 10:20

... tempera- ture. We may evaluate h ∗ and g ∗ m,i in the same way when heat and mass transfer occur simultaneously. If composition variations are not large, as in many low-rate problems, it may be adequate to ... when more than one species is transferred? §11.9 Simultaneous heat and mass transfer 667 Stagnant film model of heat transfer at high mass transfer rates The multicomponen...

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... 1 29 .3 304.4 1 096 35 0 231 5 895 .2 1 09. 0 112.5 30 4.1 1078 36 0 2 290 824.881. 891 .0 30 3.8 1054 37 3 2257 717.0 30 3 .3 1022 400 21 83 346 .9 30 2.4 94 5 500 1828 299 .2 39 1 600 11 73 295 .9 700 292 .3 T tp 2 73. 16 ... 8 ,95 4 38 4 39 8 11.57 4 83 420 401 39 1 38 9 38 4 37 8 36 6 35 2 33 6 DS-C15715 ∗ 8 ,90 0 38 4 36 5 ≈10.7 36 7 35 5 34 5 33 5 32 0...

Ngày tải lên: 07/08/2014, 10:20

... Ambrazyavichyus (1961), 32 5, 32 6, 33 9 Žukauskas and Šlanciauskas (1987), 32 5, 32 6, 33 9 Žukauskas (1972), 38 2, 38 3, 39 5 Žukauskas (1987), 38 2, 39 6 726 Appendix C: Nomenclature E,E 0 voltage, initial voltage (V) e, ... 10 −24 yocto y 10 21 zetta Z 10 −21 zepto z 10 18 exa E 10 −18 atto a 10 15 peta P 10 −15 femto f 10 12 tera T 10 −12 pico p 10 9 gig...

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... 7 43 H Hagan, G., 34 8 Hagan-Poiseuille flow, 34 8 Halocline, 674 Heat, 3 Heat capacity, see Specific heat capacity Heat conduction, see Conduction Heat convection, see Convection Heat diffusion equation multidimensional, ... velocity, 637 , 649 Critical heat flux (CHF), see Peak heat flux Cross flow, 37 4 38 4 cylinders flow field, 37 4 37 7 heat transfer, 37 7 38 0 tube bu...

Ngày tải lên: 07/08/2014, 10:20