Comparison of Marangoni condensation heat transfer characteristics on two surfaces with different temperature fields

Marangoni condensation heat transfer characteristics for water-ethanol mixture vapor on a vertical surface with temperature gradients were studied experimentally. The present heat transfer coefficients and condensation modes were compared with those on a flat vertical surface with uniform temperature, respectively. The comparison showed that, the present condensation drops tended to be denser and tinier and the sweep speed of drops was faster. Under the same condition, the present heat transfer coefficients were higher than those on the flat surface for full ethanol concentration range. The preliminary analysis also shows that, under the coaction of concentration and temperature gradients, the surface tension gradients on the condensate surface become greater, leading to the Marangoni condensation heat transfer to be further enhanced.