PROBLEME INVERSE APPLIQUE AUX TURBOMACHINES ET AUX HELICES

Abstract

The paper presents an approach in perfect fluid model for the design of turbomachine blading or marine propeller by solving the inverse problem in which the boundary conditions are related to the bound vorticity distribution on the blades in order to produce the imposed deviation angle, with a given thickness distribution of the blade required by the structure analysis. In the case of turbomachine the 3D design is performed either by a two steps S2 (meridional flow)-S1 (blade to blade flow) approach. S2 step leads to the determination of axisymmetrical stream sheets as well as the approximate camber surface of the blades. In the S1 step, the inverse problem concerning blade to blade flow for turbomachines is carried out. The flow around the unshrouded propellers is rotationnal and tridimensionnal. An inverse computation method based on the model of inviscid and rotationnal fluid subdivised into two complementary steps (axisymmetric computation + 3D panel method) is proposed for design of the propellers.