:
k , , 2...6;
[σ] , ,
[σ] = 100 .
:
.= ;
. = ;
.= .
, .
:
d=d-2 ,
2.
2
, | , | ||||
dp | d | dBH | |||
:
:
V.. = /;
V. = /;
V.= /.
( ) .
, , .
l o -c:
l , ;
d , ;
, /3,
λ , ,
λ (Re):
ν , 2 /.
:
Re < 2320, , λ = 75/Re$
2320 < Re < 10000, , λ = 0,3164/(Re)0,25;
Re > 10000, , , :
Δ , Δ = 0,04 .
1-2
L1-2 = ; d, = ; V = /
:
Re = = < ,
λ = =
:Δl = .