Spatially developing instabilities in non-Boussinesq convection flows

Convection flows are found in many industrial applications. As a result of strong nonlinearity of the governing equations associated with nontrivial fluid properties variations with temperature, multiple flow patterns exist for the same set of parameters such as Reynolds and Grashof numbers and dimensionless temperature difference. In practice, it might be preferable to suppress certain types of flows and to enhance others, i.e. the problem of intelligent control of flow instabilities arises. This study is undertaken to understand transition scenarios between different flow states. One of the aspects of this research is investigation of the response of an unstable flow system to an initially localized disturbance as usually occurs in realistic applications. This leads to convective/absolute instability analysis. Here we describe the approach and the resulting boundaries in parameter space between different types of instabilities arising in non-Boussinesq mixed convection channel flow.