, (), . - .
( ), , , , ..
() :
40 < Re < 200
Nu= 0,1 Re; (7.122)
200 < Re < 610
Nu = 0,286 Re0,8, (7.123)
; ( ; ; d ; w , ).
[ = 0,13÷1,7 /] Re = 502000
Nu = 0,123Re0,83, (7.124)
; (d ; W = w ρ ).
[ = 37÷383 /] Re = 501770
, (7.125)
.
( ) . , , ( , , ).
, max, , ε. , , w :
. (7.126)
.
7.15 |
w (. 7.15), . w , .
:
|
|
j = 1¸5; (r/r) < 1100;
30 < Re < 480
; (7.127)
480 < Re < 2000
;
5 < φ <30;
. (7.128)
(7.127) (7.128) φ , /; ρ . .
, ,
; (7.129)
Re < 40 = 1,18103; = 1,5;
40 < Re < 1200 = 3,3510-3; = 1,2;
Re > 1200 = 2,95102; = 0,9.
, :
. (7.130)
, . , , . , , ; , .
. , . .
(, ), . . .
, , ,
.
, (7.131)
, , ,
. (7.132)
, , :
, (7.133)
,
, , 1 2 1 .
. , , , , , ,
, (7.134)
. 50¸350 .
.