We study approximations by conforming methods of the solution to the variational inequality ∂ t u, v − u + ψ(v) − ψ(u) ≥ f, v − u , which arises in the context of inviscid incompressible Bingham type fluid flows and of the total variation flow problem. In the general context of a convex lower semi-continuous functional ψ on a Hilbert space, we prove the convergence of time implicit space conforming approximations, without viscosity and for non-smooth data. Then we introduce a general class of total variation functionals ψ, for which we can apply the regularization method. We consider the time implicit regularized, linearized or not, algorithms, and prove their convergence for general total variation functionals. A comparison with an analytical solution concludes this study.