Effects of Coriolis Force on Instability of Laminar Boundary Layer on a Concave Surface

Stability of laminar boundary layer having a mean velocity of Pohlhausen type was studied by solving numerically the perturbation equations when the boundary layer is subject to curvature and Coriolis force. When the channel rotates so that the Coriolis force acts toward the concave wall, the Taylor-Görtler vortices are generated on a concave surface with a weaker curvature than that in the stationary condition because of the instability effects of the Coriolis force. Vortices are suppressed and the critical Görtler number is increased when the Coriolis force acts opposite to the centrifugal force due to the wall curvature. Over a wide range of rotation rate, vortices with scales as large as the boundary layer thickness are easily generated.