Competing Instabilities for Rotating Boundary Layer Flows
In this talk we summarise some recent developments on instabilities of boundary layer flow over rotating bodies. While the rotating disk is widely acknowledged as a key test case to investigate the crossflow instability, recent theoretical and experimental studies have successfully identified the more dangerous centrifugal instability, which is present on sharp spinning geometries. We add further complexity to this problem by investigating the effect of isotropic and anisotropic roughness models for the rotating disk and, more recently, the rotating cone. The results suggest a complex interaction between competing instability mechanisms and potentially interesting implications for the design of spinning turbomachinery.