Verification and validation for microfluidic CFD simulations of Newtonian and non-Newtonian flows

Lab-on-a-chip devices are employed in different research areas to evaluate the physics of flow in micro-channels. Integration of these devices with Computational Fluid Dynamics provides a powerful platform to study complex flow behaviors in convoluted geometries. Uncertainty analysis is crucial to assure and assess the fidelity of simulation-based designs and flow predictions. However, the current uncertainty estimation is based on macroscale approaches, where some relevant error sources at the microscale are not accounted for. Moreover, there is a scarce implementation of rigorous verification and validation proce-dures for microfluidics, especially for contraction-expansion geometries. In this study, a computational verification and validation (V&V) methodology for CFD simulations of New-tonian and non-Newtonian flows in microfluidic devices is proposed. The successful imple-mentation of this systematic V&V procedure for uncertainty analysis of CFD simulations of microfluidic flow experiments in a hyperbolic contraction-expansion device elucidated the importance of accounting for additional error sources such as geometrical uncertainties at the microscale. (c) 2022 Elsevier Inc. All rights reserved.