A method for modeling at least one portion of a bathtub of a blade, the method including parametrizing a volume representing the bathtub portion as a set of markers extending from a reference transverse surface of the blade, the blade physically including the markers, and each marker associated with an elementary surface selected among a plurality of elementary surfaces forming a partition of at least one portion of the reference transverse surface; and defined by a marker height relative to the reference surface; determining optimized values of the marker heights relative to a given aerodynamic and/or thermal criterion; reproducing, on an interface of the device, the values thus determined.