Experimental study of airflow and heat transfer above a hot liquid surface simulating a cup of drink

The airflow visualisation by PIV (Particle Imagery Velocimetry) above the cup shows that the flow is complex with unsteady plumes detachment and vortex formation. The combined convection and evaporation lead to upward airflow with temperature fluctuations which become significant for drink temperature above 55 °C. This can be explained by the non-linearity between saturated pressure of water and its temperature. This work could highlight how volatile aromas are released from hot drink.