Category
Applied
Description
Direct Numerical Simulation (DNS) is an important tool in fluid mechanics as it directly solves the governing equations and resolves the turbulent structures in a flow. Surprisingly, this foundational method has not yet been validated in ANSYS Fluent, especially for separated boundary layers. This study investigated the capability of Fluent to resolve turbulent flow in a wavy channel using DNS. The results were compared with data from previous numerical studies on this canonical flow. The simulation was performed at a fixed bulk Reynolds Number of 6760 over a wavy wall with an amplitude-to-wavelength ratio of 0.05. Under these conditions, the flow separated from the wall on the leeward side of the wave and reattached on the front of the following wave. To validate the Fluent DNS solver for separating and reattaching flow, the results were compared with literature values for the same conditions. The mean pressure and shear stresses along the wall, mean stream-wise and wall-normal velocity profiles, and mean turbulent kinetic energy profiles were calculated and compared with the literature results. In general, the Fluent results were in good agreement with the literature values. However, the mean pressure and shear stresses along the wall deviated slightly from the referenced study, likely because the referenced paper utilized the immersed boundary method to impose the wavy wall no-slip boundary condition. These findings prove that ANSYS Fluent can conduct DNS for complex geometries involving separating and reattaching boundary layers.
Direct Numerical Simulation of Turbulent Flow in a Wavy Channel: A Validation Study
Applied
Direct Numerical Simulation (DNS) is an important tool in fluid mechanics as it directly solves the governing equations and resolves the turbulent structures in a flow. Surprisingly, this foundational method has not yet been validated in ANSYS Fluent, especially for separated boundary layers. This study investigated the capability of Fluent to resolve turbulent flow in a wavy channel using DNS. The results were compared with data from previous numerical studies on this canonical flow. The simulation was performed at a fixed bulk Reynolds Number of 6760 over a wavy wall with an amplitude-to-wavelength ratio of 0.05. Under these conditions, the flow separated from the wall on the leeward side of the wave and reattached on the front of the following wave. To validate the Fluent DNS solver for separating and reattaching flow, the results were compared with literature values for the same conditions. The mean pressure and shear stresses along the wall, mean stream-wise and wall-normal velocity profiles, and mean turbulent kinetic energy profiles were calculated and compared with the literature results. In general, the Fluent results were in good agreement with the literature values. However, the mean pressure and shear stresses along the wall deviated slightly from the referenced study, likely because the referenced paper utilized the immersed boundary method to impose the wavy wall no-slip boundary condition. These findings prove that ANSYS Fluent can conduct DNS for complex geometries involving separating and reattaching boundary layers.
