Effects of suction/blowing on the lower branch modes of the incompressible boundary layer flow due to a rotating disk (Q957850)

For a disk rotating at sufficiently high Reynolds numbers with reasonably small scaled frequencies, the author develops a self-consistent rigorous expansion, accounting for the nonlinearity, non-parallelism and influence of viscous and Coriolis forces on the suction and blowing. The imposition of suction or blowing on the three-dimensional incompressible boundary layer is shown to have a significant effect on the mean flow, which in turn, influences the stability properties of this boundary layer. The influence of the nonlinearity has been analyzed using time-dependent solutions by deriving an amplitude equation as a result of a balance between the acting forces. Regardless of the positive or negative frequency waves and suction or blowing, the nonlinearity has always a destabilizing impact on the three-dimensional boundary layer. This effect is more pronounced for positive short-wavelength waves. The effects of suction/blowing on the linear results and the finite amplitude effects have been studied numerically.