0, 0 (=E or BE)

Steady state or entrance to SC or BC (n or k =0)

A, E, T (=AE)

Outlet, entrance, total (i.e. from outlet to entrance)

B, S

Basic channel or sub-channel (=channel region)

A, S, F, D, X (P = A + S + F + D + X) and G

Acceleration, static head, direct and additional friction, external pressure differences (in connection with ΔP) and pressure differences due to changes in mass flux

Mn, BMk

Mean values over SC or BC nodes

Nn, Bk

SC or BC node boundaries (n = 0 or k = 0: Entrance)



S, W

Steam, water

P, T

Derivative at constant pressure or temperature


Tube wall surface