2024/11/21 by Zhiyong Li, Li, Zhi-yong, Xiao, Ya-kang +8
Engineering · #FOS: Physical sciences #Fluid Dynamics (physics.flu-dyn) #Fluid Dynamics Simulations and Interactions #Fluid Dynamics and Vibration Analysis #Spacecraft and Cryogenic Technologies
paper · pdf · doi:10.48550/arxiv.2411.14116
openalex publication_date 2024/11/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In this research, a two-dimensional numerical simulation is conducted to determine the equivalent wall slip length for flow around a circular cylinder featuring a super-hydrophobic surface. The super-hydrophobic surface is modeled as an alternating distribution of slip and no-slip conditions along the cylinder's surface. The smallest unit of this alternating pattern is referred to as a monomer. The study takes into account the Reynolds number and two critical dimensionless parameters: the gas fraction (GF) and the ratio l/a. GF indicates the proportion of the slip length relative to the total length of the monomer, while l/a denotes the ratio of the monomer length (l) to the cylinder's radius (a). The ranges considered for the Reynolds number, GF, and l/a are from 0.2 to 180, 0.1 to 0.99, and π/80 to π/5, respectively. A dimensionless number, the Knudsen number (Kn), is introduced to measure the ratio between the equivalent slip length (λ) and the cylinder's diameter (D). By equating the integral wall friction resistance on the cylinder surface, a quantitative relationship between the equivalent Kn and the parameters (Re, GF, l/a) is established. A meticulous comparison of flow parameters between the equivalent slip length model and the slip-no-slip scenario reveals that the slip length model is an effective approximation for the slip-no-slip alternating model.