Forced and mixed convection experiments in a confined vertical backward facing step at low-Prandtl number

Abstract In this paper, we present experimental results for a non-isothermal vertical confined backward facing step conducted with low-Prandtl number fluid. The eutectic alloy gallium–indium–tin is used as the working We experiments different Reynolds and Richardson numbers covering both forced mixed convection regimes. Time-averaged velocity profiles were measured at six streamwise positions along test section center-plane so-called permanent magnet probes. local Nusselt was in spanwise directions heating plate mounted right after step. further ran RANS simulations of experiment to study qualitative influence assuming constant specific heat flux thermal boundary condition plate. show expected behavior studied regimes, while do not. This explained by how defined. performed an order magnitude estimate forced- transition onset. shows good agreement data, although measurements are needed validate estimated threshold. measurement fluctuating quantities remains open task be addressed future experiments, since probe equation needs adjustments. Graphical