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Main Authors: Cao, Yufan, Zhang, Yixin, Lv, Pengyu, Duan, Huiling
Format: Preprint
Published: 2023
Subjects:
Online Access:https://arxiv.org/abs/2312.17564
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author Cao, Yufan
Zhang, Yixin
Lv, Pengyu
Duan, Huiling
author_facet Cao, Yufan
Zhang, Yixin
Lv, Pengyu
Duan, Huiling
contents Effective slip boundary conditions for flows over periodic micro-structured surfaces containing a secondary immiscible fluid are derived. The primary fluid is in the Cassie state, while the geometries of the micro-structures can be arbitrary. We investigate the impact of the second immiscible fluid on external flow, introducing the effect caused by the viscosity difference between two fluids and the inertia effect of the second fluid into classic Navier slip condition. The effective slip length obtained from our theory for flows over rectangular micro-structures is in good agreement with prior analytical findings. We also apply the theory to mushroom-like micro-structures. The derived effective slip velocity also matches well with two-phase numerical simulations. Implementing the slip boundary conditions on micro-structured surfaces produces external flow fields that are aligned well with the simulation results. Employing a multi-scale homogenization method, we dispose of two-phase flows characterized by strong coupling at the fluid-fluid interface. By introducing the framework of lid-driven cavity approximation, our theory finds practical applications across various scenarios.
format Preprint
id arxiv_https___arxiv_org_abs_2312_17564
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle An effective slip boundary for micro-structured surfaces containing a second immiscible fluid
Cao, Yufan
Zhang, Yixin
Lv, Pengyu
Duan, Huiling
Fluid Dynamics
Effective slip boundary conditions for flows over periodic micro-structured surfaces containing a secondary immiscible fluid are derived. The primary fluid is in the Cassie state, while the geometries of the micro-structures can be arbitrary. We investigate the impact of the second immiscible fluid on external flow, introducing the effect caused by the viscosity difference between two fluids and the inertia effect of the second fluid into classic Navier slip condition. The effective slip length obtained from our theory for flows over rectangular micro-structures is in good agreement with prior analytical findings. We also apply the theory to mushroom-like micro-structures. The derived effective slip velocity also matches well with two-phase numerical simulations. Implementing the slip boundary conditions on micro-structured surfaces produces external flow fields that are aligned well with the simulation results. Employing a multi-scale homogenization method, we dispose of two-phase flows characterized by strong coupling at the fluid-fluid interface. By introducing the framework of lid-driven cavity approximation, our theory finds practical applications across various scenarios.
title An effective slip boundary for micro-structured surfaces containing a second immiscible fluid
topic Fluid Dynamics
url https://arxiv.org/abs/2312.17564