Numerical analysis rotating flows

This paper investigates the effects of surface roughness modelled with the YHP model on the convective instability of some flows in the rotating BEK flows. Linearised perturbation equations are solved using Chebyshev polynomials. The results reveal that presence of surface roughness on the rotating disk surface changes the instability characteristics of the flows. The Type I mode onsets at higher Reynolds number as roughness increased. However, the Type II mode onsets at earlier Reynolds numbers. The findings also reveal a decrement in the quantity of co-rotating vortices with enhanced roughness. Therefore, it can be concluded that increased roughness has a stabilising effect on the Type I mode but a destabilising effect on the Type II mode. Keywords: Bödewadt flow, Flow control, Von Karman flow