Condensation on Horizontal Tube: Evaluation of Ten Heat Transfer Correlations

Ten existing correlations were selected to calculate the heat transfer coefficient during condensation on the external surface of a horizontal tube. These models were compared to a dataset of over 1000 experimental measurements. Statistical and graphical analyses were performed to assess their accuracy against experimental data. Results confirm that Nusselt’s correlation remains the reference in this field. Discrepancies of approximately 14% are observed in other models, such as those proposed by Bromley, Sparrow and Gregg, and Sadasivan and Lienhard. In contrast, the remaining correlations significantly overestimate the experimental values. Finally, a new semi empirical correlation is proposed, achieving a mean error of 14.66% and demonstrating reliability comparable to the most robust existing models. The newly proposed model introduces a modified dependence on the Jacob number, offering improved agreement with experimental data across multiple fluid types, especially in transitional and high-heat-flux regimes. This adjustment enhances the general applicability and accuracy of the model, providing more reliable predictions across a broader range of operating conditions.