Computational investigation of air and water flow past laminar wake characteristics behind a circular cylinder

This study presents a comprehensive computational investigation of two-dimensional viscous flow around a circular cylinder, serving as a foundational benchmark for exploring more complex geometries, such as those encountered in ship and submarine hulls. Utilizing the realizable k - ∈ turbulence model within the ANSYS Fluent environment, the research captures essential flow characteristics, including velocity profiles, pressure distributions, and turbulence intensity. These findings validate the effectiveness and robustness of the model for applications in the industrial, marine and aerospace engineering domains. The simulations consider both air and water as working fluids, analyzing flow behavior at varying cylinder positions (10-40 mm) and inlet velocities (5-20 m/s) for four different cases. The model successfully reproduces key phenomena such as vortex shedding, boundary layer separation, and pressure gradients. Due to its higher viscosity, water exhibits vortical structures that are more pronounced than those of air. In addition, axial positioning of the cylinder significantly affects wake development and flow evolution. The study analyzed cylinder-induced vortices by extracting velocity profiles along four axial lines ( L = 100 m m ) around a cylinder ( D = 10 m m ) with 30 m m spacing. The Upstream ( A 1 , A 2 ) and downstream ( W 1 , W 2 ) lines distinguished air/water phases in multiphase flow. Normalized axial positions ( 0 − 0.3 , representing y = 0 m m to 30 m m ) were compared at two velocities ( 5 m s − 1 and 20 m s − 1 ) to evaluate vortex development and wake structure. This work provides a validated computational framework that can be readily extended to the analysis of more intricate flow configurations.