Numerical simulation of drop impingement onto superheated textured walls

Abstract

Spray cooling stands out as a suitable method for cooling of high-end electronic devices. Texturing of the surface can further increase the cooling performance. Understanding the flow dynamics and heat transport during the impingement of a single drop is crucial to gain an in-depth insight into complex phenomena governing spray cooling. In this study, the influence of textured walls on drop impingement dynamics and heat transfer is investigated. Numerical simulations are conducted within the OpenFOAM framework. Our solver accounts for evaporation, conjugate heat transfer and a dynamic contact angle. We study wall topographies comprised of cubes, rectangular grooves, pyramids and triangular grooves. Our results reveal that textured surfaces significantly increase both wetted area and contact line length compared to a smooth wall, with cubes demonstrating the best performance. Furthermore, we observe a significant increase in heat flow during the sessile drop phase. This study lays the foundation for designing surfaces that optimize heat transfer for drop impingement and spray cooling.