3D shape optimisation of turbomachinery blading

The shape of HP gas and steam turbine stages, as well as of an LP exit stage of a steam turbine, is optimised numerically using a code Optimus and 3D RANS solver FLowER. The numerical method draws on direct constrained optimisation based on the method of deformed polyhedron. Values of the minimised objective function, that is stage losses with the exit energy are found from 3D viscous compressible computations. There are constraints imposed on the mass flow rate, exit swirl angle and reactions. Among the optimised parameters are stator and rotor blade numbers, stagger and twist angles, stator sweep and lean, both straight and compound. The optimisation gives new 3D designs with increased efficiencies.