Numerical study on the effect of Marangoni convection on condensation heat transfer of hydrophobic and hydrophilic hybrid inclined surfaces

Abstract

The research aims to enhance condensation heat transfer efficiency in microelectronics and energy conversion systems by examining the impact of Marangoni convection on droplet heat transfer dynamics on hybrid hydrophilic-hydrophobic surfaces. It evaluates droplet contact angle, surface inclination and heat transport mechanisms, integrating the thermocapillary effect and employing three dimensionless parameters. By establishing this theoretical framework, the study provides predictive insights to optimize heat transfer performance. It improves the model to compute the maximum radial radius for droplet detachment, considering droplet sliding, rolling or jumping as detachment modes, mirroring real-world scenarios. Utilizing a numerical analysis approach, the study employs the Wenzel and Cassie–Baxter wettability models to simulate condensation on hybrid surfaces. These simulations are performed using thermal resistance network (TRN) calculations implemented in MATLAB. The research uncovers four pivotal findings: (a) The Wenzel model indicates an optimal heat transfer range for hybrid surfaces with specific contact angles, CAH (contact angle hysteresis) and W_FWC values. (b) Heat flux performance improves with increasing surface inclination angles under the Wenzel mode, a trend that becomes more pronounced at higher angles. (c) The Cassie–Baxter model, at a CAH of 3°, demonstrates superior efficiency across various surface inclinations and CAH values, outperforming alternative models. (d) For all widths of the hydrophilic region, the Wenzel model exhibits superior heat flux performance at CAH values of 20° and above.