LAMINAR FREE-CONVECTION CONDENSATION OF SATURATED VAPORS IN THE NEAR-CRITICAL REGION

A numerical analysis is presented for laminar free convection condensa tion of saturated vapors of Hater and carbon dioxide on a vertical fla t surface in the reduced temperature range T-s/T-c = 0.990-0.9998. The heat transfer coefficient can be correlated by the equation containin g the correction for the convection and inertia terms in the case of c onstant physical properties, when the specific heat is evaluated using its average value over the surface temperature T-w to the saturation temperature T-s and the other physical properties are evaluated at the film temperature. The reduction of condensation mass flux or the heat flux at the vapor-liquid interface due to the convection term is expr essed as the same function of the phase change number as the case of c onstant physical properties, when the specific heat is evaluated using its average value over the temperature T-x = T-w + (1/3)(T-s - T-w) t o T-s.