Effect of concentric surface roughness on traveling disturbances in the rotating disk boundary layer
Year: 2025
Type: article
Abstract: The linear stability of the rotating disk boundary layer with surface roughness is investigated, building upon the earlier work by Harris [“Stability of the flow over a rough rotating disk,” Ph.D. thesis (University of Warwick, 2013)] and Garrett et al. [“On the stability of von Kármán rotating-disk boundary layers with radial anisotropic surface roughness,” Phys. Fluids 28, 014104 (2016)]. The study employs the Yoon et al. [“Flow and heat transfer over a rotating disk with surface roughness,” Int. J. Heat Fluid Flow 28, 262–267 (2007)] approach for modeling concentric surface roughness, where the roughness is defined as a function of the radial direction coupled with a spatial-averaging of the base flow. Neutral stability curves and critical conditions for linear instability are computed for varying roughness factors and for traveling wave disturbances with temporal frequencies ω¯∈[−10,10]. The results demonstrate that surface roughness stabilizes the type-I crossflow instability and destabilizes the type-II Coriolis instability. Finally, a high-Reynolds number asymptotic analysis is undertaken for the upper branch of the neutral stability curve associated with the crossflow instability.
Source: Physics of Fluids
DOI: 10.1063/5.0290340
Authors: Maha Alshahrani, Christian Thomas, Sharon O. Stephen, Zahir Hussain
Language: English
Subfield: Computational Mechanics
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4414205653