Stability of the Blasius boundary layer over a heated plate in a temperature-dependent viscosity flow

Miller, Robert, Garrett, Stephen J, Griffiths, Paul T and Hussain, Zahir (2018) Stability of the Blasius boundary layer over a heated plate in a temperature-dependent viscosity flow. Physical Review Fluids, 3. ISSN 2469-990X

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Abstract

We present complementary numerical and asymptotic studies of the flow over a heated, semi-infinite flat plate for a fluid with temperature-dependent viscosity. Liquid-type viscosities are found to entrain both the velocity and temperature profiles closer to the plate with increasing temperature sensitivity; gas-type viscosities are found to exhibit the reverse effect. A linear stability analysis is presented and we find that increasing the temperature dependence of the fluid (from gas- to liquid-type behavior) results in an increased critical Reynolds number to a point of maximum stability. Using an energy-balance approach, we determine that this behavior is primarily driven by the inviscid instability of the modified steady flow, rather than being a result of modified viscous instability effects. Application and extension of the results are considered in the context of chemical vapor deposition.