Multiphase Eulerian–Eulerian study on sedimentation and thermal transport of Ti3C2Tx MXene nanofluids in a heated microchannel

Abstract

Sedimentation plays a critical role in accurately assessing the heat transfer performance of microchannel-based thermal systems. This study investigates the sedimentation behavior of MXene–water nanofluid (MWNF) in a bottom-heated 2D microchannel with and without internal fins using the two-phase Eulerian–Eulerian (EE) approach. The analysis also focuses on the impact of particle concentration (ϕ), internal fins, and sphericity-sensitive drag models such as Haider–Levenspiel (HL) and Schiller–Nauman (SN) on heat transfer performance and nanoparticle (NP) dynamics. Results show that the HL model captured the behavior of 2D Ti₃C₂ MXene (TMX) NPs more accurately, where SN overestimated the average Nusselt number (Nu) by 1.15 % and the Euler number (Eu) by 5.1 %, for higher ϕ. Finned microchannels significantly influence NP sedimentation, which increased the local ϕ by 49.83 % compared to unfinned configurations and disrupted the symmetry of particle distribution across the microchannel. While both drag models estimated similar Nu at low concentrations, deviations widen with increasing ϕ, particularly in finned geometries. At ϕ = 3 wt.%, Nu enhancement reached 15.78 % with HL versus 13.09 % with SN, reinforcing the superiority of the HL model in microscale simulations involving 2D materials. The findings also demonstrated that while ϕ influences heat transfer, its effect is moderated by fin-induced thermal disruptions, highlighting the need for coupled consideration of NF properties and internal geometries in microscale heat exchanger design.