Change of dynamic contact angle of a drop spreading over copper surface

This work presents the comparison between the change of a dynamic contact angle during drop spreading over copper surfaces obtained in the experiment and calculated by using empirical correlations (Bracke et al., Jiang et al., Seebergh et al.). It is found that these correlations are applicable for the case of drop spreading over a smooth surface or over a rough surface into the low capillary number region (2.510-7). Dynamic contact angles obtained experimentally increase with increasing capillary number, besides it increases significantly on more rough surfaces. However the calculated values of angles do not depend on Ca.