Absolute and convective instabilities in the incompressible boundary layer on a rotating disk with temperature-dependent viscosity

The absolute and convective instability of Von-Kármán rotating disk flow with a temperature dependence viscosity of the form μ′ = μ∞/[1 + ϵ(T − T∞)/(Tω − T∞)] is investigated. With the use of a spectral method, the linear stability equations are formulated and then solved numerically. Solutions have been obtained for various values of the parameter ϵ which controls the temperature dependence of viscosity. It is established the stability of the flow is particularly sensitive to changes in viscosity and even for small positive values of ϵ the flow is much more unstable compared to the constant viscosity case.