Effect of Microchannel Geometry on Nanoparticle Deposition in Nanofluid Flow

Abstract

Particle deposition poses a significant challenge in the application of nanofluids within microchannels. This study provides an angle‐ and radius‐resolved numerical analysis of nanoparticle deposition in bent microchannels and clarifies how microchannel geometry regulates deposition through curvature‐induced acceleration, secondary flow, and particle‐wall encounter mechanisms. The results demonstrate that the particle deposition number per unit area decreases from 28.612 to 8.941 as the bending angle increases from 30° to 120°. Furthermore, particle deposition per unit area decreases from 11.922 to 4.769 as the bending radius increases from 0.2 mm to 0.4 mm. The inlet and curved segments exhibit significantly higher particle deposition than the other segments. Specifically, deposition in the inlet segment is approximately 10 times higher than that in the other segments, while deposition in the curved segment is approximately three times higher. The Reynolds number and Dean number are identified as critical parameters for linking primary flow, curvature‐induced secondary vortices, and deposition risk. These findings provide quantitative insights and a mechanistic framework for the rational design and optimization of nanofluid microchannel cooling systems.