Droplet train impinging onto a solid substrate surface

The heat transfer characteristics are experimentally investigated when a droplet train impinges onto a heated surface. A steady-state experimental method is applied to measure the heat transfer coefficient continuously. The boiling regime, transition of the splashing regime, and post-transition regime can be observed. The hydrodynamic pattern significantly changes with an increase of wall temperature. The associated heat transfer characteristics are diverse in different regimes. In the boiling regime, the heat flux increases with an increase of wall temperature. A peak value is reached when the splashing is just established. However, when it steps into the transition regime, the wall heat flux reduces with an increase in wall temperature. At the end of the transition regime, a sudden drop of the heat flux is found. In the post-transition regime, the heat flux increases with an increase of wall temperature again, whereas the heat transfer coefficient is kept a constant.