空调翅片管换热器设计计算(4)

查干空气物理性质表

肋片/当量直径th(mh')mh'

)(12a a pf f k v t t C Q q -=ρa

g V w HB

=ε/max g w w =mm s n L 4.252=⨯==-+--⨯-⨯=-+---=1.06.14.75.20)1.06.1()4.75.20(2)

)((211f f b f f b eq s d s s d s d δδ=-

eq d L =

=f eq amx ef d w R ν1.1)(⨯=m eq n ef e a

of d L R d c λψαf

f a m δλ0

2='('1)(10.35ln ')2b d h ρρ=-+1

b s d ρ

=' 1.27ρ=b f b f

a a ++η