() dx, dy, dz (. 7.2) , λ, ρ . x, y z, wx, wy wz. t . . .
, dydz d τ,
.
,
.
d τ :
.
y z
;
.
d τ
.
(1.34)
.
,
.
, d τ, (7.21)
.
,
dQ, ,
.
,
.
,
,
, (7.66)
.
(7.66) , -. ().
wx = wy = wz = 0 (7.66) (7.23).
,
. (7.67)
(7.66) , .. . , , - , .
. , , . , , ().
|
|
(), (7.64):
.
, (. 1.3.6), :
.
() , , :
. (7.68)
, , .
:
, (7.69)
.
- (7.66).
. (7.70)
, ,
;
.
, . :
. (7.71)
, , :
. (7.72)
. , Re Fr, () L. , , L = d, L = l, L = R ..
, (7.73)
.
, . Nu . , ,
. (7.74)
,
, ( ).
Pr . ( ), 3 ÷ 300. , , ( Pr = 0,67; Pr = 0,72; Pr = 0,8; Pr = 1).
|
|
(7.74) :
. (7.75)
(7.75) Fo Ho, , ,
. (7.76)
(7.76) .
, , , :
. (7.77)
( ) :
. (7.78)
, , , , () :
,
ρ ρ0 ().
Δ t , bΔ t (b ). :
. (7.79)
, Gr , ,
. (7.80)
Pr ≈ 1 (7.79) .
, :
, (7.81)
, , , ;
; (7.82)
, (7.83)
(G ) .
.
. , (7.77) ; (7.79) ..
:
.
, , , . , . , , , , .