Linear stability analysis of boundary layer flows with thermal effects*

The study of shear flows with thermal effects finds several applications in weather prediction, heat exchangers, chemical vapor deposition (CVD), among others. In some of these applications, for example in CVD, one needs to ensure a laminar flow to keep the quality of the process. To investigate the thermal influence in shear flows, a local linear stability approach is adopted in this work. This analysis allows the investigation of mixed convection flows including their response to infinitesimal disturbances. The incompressible form of the Navier-Stokes equations is employed together with the Oberbeck-Boussinesq approximation to model the present flows and, therefore, include buoyancy effects. The setup studied consists of the Blasius boundary layer heated from below. To assess the stability properties with respect to critical parameters (Reynolds and Grashof numbers, oblique wavenumbers), modal and non-modal analyses are employed.