HTCO is only calculated in turbulent flow in PHOENICS,
if you want to get that for laminar flow, you can calculate
the it by ground or IM-FORM etc. Then HTCO is
HTCO=2*KOND/Y , (W/m^2/K)
here, KOND: the heat conductivity of fluid(W/m/K)
Y : the size of grid.(m)