. A1,==DLflRe,εRefL/D 1 2 5 10 15 20 30 40 50 1. 104 1, 65 1, 50 1, 34 1, 23 1, 17 1, 13 1, 07 1, 03 1 2 .10 4 1, 51 1,40 1, 27 1, 18 1, 13 1, 10 1, 05 1, 02 1 5 .10 4 1, 34 1, 27 1, 18 1, 13 1, 10 1, 08 1, 04 1, 02 1 1 .10 5 1, 28 1, 22 1, 15. 1, 15 1, 10 1, 08 1, 06 1, 03 1, 02 1 1 .10 6 1, 24 1, 11 1,08 1, 05 1, 04 1, 03 1, 02 1, 01 1Với: Re = 1, 4 317 5 .10 5 19 5,5=DL⇒ Nu = 0, 018 .1, 1447. (1, 4 317 5 .10 5)0,8 = 274,57 31 - Hệ số cấp nhiệt 1 :5554,62 ,1 02865,0.57 31, 274. 1 ===TkDNuλα(W/m2.K)GVHD:. d 1 .B = 0,6 21. 1 ϕ. 1 bp+ d 1 . 1 ϕ. 1 bp d 1 .B = 1 ϕ. 1 bp(0,6 21 + d 1 )⇒ 19 153,0) 019 459,06 21, 0. (15 562,09 81, 0. 019 459,0)6 21, 0(. 1 1 1 1=+=+=dpBdbϕ839 ,10 5)55.842 ,12 500.( 019 459,055.004 ,1 ).842 ,12 500.(.004 ,1 111 1=++=++=...