In aeronautical CFD, engineers require accurate predictions of the forces and moments but they are less concerned with flow-field accuracy. Hence, the so-called "goal oriented" mesh adapatation strategies have been introduced to get satisfactory values of functional outputs at an acceptable cost, using local node displacement and addition of new points rather than mesh refinement all over the computational domain. Most often, such methods involve the adjoint vector of the functional of interest. Our purpose is precisely to present a new goal oriented mesh adaptation strategy in the framework of finite-volume schemes and discrete adjoint method. It is based on the total derivative of goal with respect to (w.r.t.) mesh nodes. More precisely, a projection of this derivative, removing all components corresponding to geometrical changes in the solid walls or the support of the output, is used to adapt the meshes. The method is first demonstrated for an academic problem (1D Poisson equation). It is then assessed for Euler flows.