On the Landau-Levich problem for a viscoplastic fluid

A systematic investigation of the Landau-Levich problem of a viscoplastic material (Carbopol 980 is \npresented). The validity of the Landau-Levich scaling is assessed via integral scale measurements of \nthe width of the coating films thickness performed for various Carbopol concentrations in the presence \nand in the absence of wall slip. To gain a deeper insight into the physical origins of the experimentally \nobserved deviations from the classical 2/3 scaling a full characterisation of the time resolved flow field \naround the moving solid is performed and the main differences of the viscoplastic flow patterns with \nrespect to their Newtonian counterpart are highlighted. The experimental investigation is complemented \nby a preliminary asymptotic analysis performed within the framework of the Bingham model.