Numerical Study of the Effect of Rib Height in Two-Phase Flow on the Heat Transfer Coefficient in a Vertical Ribbed Channel

A thorough numerical examination of vertical ribbed duct heat transfer performance due to rib height and geometry adjustments under air-water two-phase flow conditions is provided.The numerical analysis through the CFD approach implemented both the VOF model with k- turbulence model to simulate three rib patterns including circular, triangular and rectangular types across different air and water velocity ranges from 4.38 to 13.16 m/s and 0.328 to 0.986 m/s, respectively.Heat transfer performance as well as flow behavior depend heavily on rib height together with their shape.Triangular ribs demonstrated maximum thermal efficiency through their ability to produce extensive turbulence and mixing among all tested shapes.Tests revealed a maximum heat transfer coefficient of 11,200 W/m K for triangular ribs during peak water velocity along with peak air velocity whereas circular and rectangular ribs exhibited maximum heat transfer coefficients of 10,600 W/m K followed by 10,000 W/m K, respectively.Triangular ribs performed the best by transferring 2,600 W of maximum heat energy which surpassed the heat energy reached by circular (2,500 W) and rectangular (2,300 W) configurations.Vertical twophase systems achieve highest efficiency in heat transfer when their ribs are properly optimized for triangular geometry that leads to excellent performance in cooling applications.