A HEAT TRANSFER TEXTBOOK - THIRD EDITION Episode 1 Part 1 pdf

... [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 =...

Ngày tải lên: 07/08/2014, 10:20

... 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...

Ngày tải lên: 07/08/2014, 10:20

... and J. P. Hart- nett, editors, Advances in Heat Transfer, volume 6, pages 50 4 56 4. Academic Press, Inc., New York, 1970. [6.14] A. A. Žukauskas and A. B. Ambrazyavichyus. Heat transfer from a ... that of predicting laminar convection in a pipe. 7 .2 Heat transfer to and from laminar flows in pipes Not many industrial pipe flows are laminar, but laminar heating and cool- in...

Ngày tải lên: 07/08/2014, 10:20

... fins of a heat exchanger may form a rect- angular passage through which air flows. Sometimes, the passage cross- section is very irregular, as might happen when fluid passes through a clearance between ... situations, but all must be viewed critically. Many are based on limited data, and many incorporate systematic errors of one kind or another. In the face of a heat transfer situa...

Ngày tải lên: 07/08/2014, 10:20

... by Fujii and Imura [8. 16], Vliet [8. 17], Pera and Gebhart [8. 18] , and Al-Arabi and El-Riedy [8. 19], among others. 8. 5 Film condensation 431 on the same basis. The integration of eqn. (8. 47) subject ... 434 Natural convection in single-phase fluids and during film condensation 8. 5 Figure 8. 12 Results of the exact b.l. analysis of laminar film condensation on a vertical plate [8. 36]...

Ngày tải lên: 07/08/2014, 10:20

... on natural convection heat transfer from a horizontal plates. Int. J. Heat Mass Transfer, 17(1):135–1 42, 197 4. 458 Heat transfer in boiling and other phase-change congurations 9. 1 Figure 9. 1 ... Natural convection heat transfer from a plate with arbitrary inclination. Int. J. Heat Mass Transfer, 15(4): 755–767, 19 72. [8.17] G. C. Vliet. Natural convection local...

Ngày tải lên: 07/08/2014, 10:20

... quite ac- curate and widely-used, semi-empirical equation for correlating surface 470 Heat transfer in boiling and other phase-change congurations Đ9 .2 Table 9 .2 Selected values of the surface ... 25 8 2. 80 25 5 2. 29 25 3 1.95 Isopropyl alcohol 10 to 100 22 .90 0.0789 Mercury 5 to 20 0 490.60 .20 49 Methane 90 18.877 100 16. 328 115 12. 371 Methyl alcohol 10 to 60 24...

Ngày tải lên: 07/08/2014, 10:20

... 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...

Ngày tải lên: 07/08/2014, 10:20

... 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...

Ngày tải lên: 07/08/2014, 10:20

... §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...

Ngày tải lên: 07/08/2014, 10:20

... 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...

Ngày tải lên: 07/08/2014, 10:20

... 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