Development of a general correlation for free convection vapor condensation over a horizontal tube in the presence of a noncondensable gas

In applications involving external condensation in the presence of noncondensable gases (NCG), there is a growing interest horizontal tubes because they minimize condensate resistance, and hence reduce adverse effects NCGs. literature, experimental heat transfer rates are summarized empirical correlations that fit underlying data, but do not cover spectrum possible steam-NCG mixtures thermal conditions. this work, we aim at developing general correlation applicable to wide range physical geometrical We first present CFD model for laminar free convection regimes, taking into account resistance gas phase liquid condensate. The validated against recent data on steam-N2 steam-CO2 mixtures. predictions agree well with being mostly within uncertainty. Subsequently, close 200 parametric simulations conducted steam-air across steam mass fraction (0.05–0.99), wall temperature subcooling (5-50 K), pressure (1–5 bar) tube diameter (0.01–0.04 m). resulting cast compact compatible analogy. proposed good agreement literature.