A finite-volume method for simulating contact lines on unstructured meshes in a conservative level-set framework

•Numerical simulations of contact lines on unstructured meshes are performed.•The contact angle is imposed through a sub-grid scale curvature at contact line.•Distance extensions in the Blind Spot allow accurate curvature computation at contact line.•The numerical method is validated on complex geometries.•The drop detachment from a fiber is simulated. Accurate numerical simulation of moving contact lines on complex boundaries with surface wettability effect remains a challenging problem. In this paper, we introduce a robust and accurate method to perform 3D contact line simulations on unstructured meshes with an imposed contact angle. The contact angle is imposed through a sub-grid scale curvature term and the contact line motion is enabled thanks to partial slip on the wall. Moreover, an original strategy has been designed to improve normal and curvature computation at contact line from the level-set field. The whole method is validated on 2D and 3D test cases and shows good mass conservation properties. The drop detachment from a horizontal fiber due to gravity or surface tension is then investigated. For this purpose, dynamic mesh adaptation is used to keep high resolution around the interface with moderate number of cells. These realistic cases demonstrate the ability of the numerical method to handle surface wettability effects on resolved complex geometries.