Two-dimensional sails in a uniform potential flow

We consider a spatially two-dimensional potential flow model for the shape of and lift generated by a single or a pair of inextensible membranes or `sails' in a uniform stream. The problem is solved numerically via the boundary integral method. Of interest are (i) the `luffing' of a sail, which occurs when it is nearly aligned with the oncoming stream, (ii) the interaction of a pair of sails that share a common near-field, and (iii) possible optimal distributions of chord between two sails and relative orientations that can maximize the total lift generated.