Heat transfer enhancement in turbulent boundary layers with a pulsed slot jet in crossflow

The convective heat transfer enhancement in a turbulent boundary layer (TBL) employing pulsed, slot jet crossflow is investigated experimentally. A parametric study on actuation frequencies and duty cycles performed. actuator flush-mounted that injects fluid into well-behaved zero-pressure-gradient TBL over flat plate. heated-thin-foil sensor measures the time-averaged coefficient downstream of location flow field characterised by means Particle Image Velocimetry. results show both penetration streamwise direction overall Nusselt number increase with increasing cycle. frequency at which maximised independent topology considerably altered pulsation. wall-attached rises from accompanied pair counter-rotating vortices promote entrainment mixing. Eventually, simplified model proposed decouples effect pulsation cycle enhancement, good agreement experimental data. cost also quantified terms amount injected during actuation, leading to conclude lowest most efficient for enhancement.