CFD investigation on thermal–hydraulic performance of flow boiling within micro‐pillar array surfaces

Abstract Micro‐structured surfaces are widely applied to enhance surface wettability and reduce hydraulic resistance. The study employs computational fluid dynamics (CFD) theory to investigate the flow boiling heat transfer performance of micro‐pillar array surfaces. A three‐dimensional dual‐channel model with micro‐pillar arrayed surface is developed. The volume of fluid (VOF) model is utilized to capture the two‐phase flow behaviour, and the mass transfer process is calculated by the Lee model. R134a is used as a working fluid undergoing phase transition. The effects of micro‐pillar height, diameter, and degree of subcooling are investigated. Parametric analyses revealed that the performance evaluation criterion (PEC) decreased by 18% and 47.9% with increasing pillar height (1–4 mm) and diameter (1–6 mm), respectively, due to flow stagnation and elevated friction losses. The performance evaluation criterion (PEC) were positively correlated with elevated subcooling levels. The optimal geometry (3 mm height and 1 mm diameter) achieved a 58.6% PEC superiority over traditional herringbone corrugations.