On the role of three-dimensional inverse design methods in turbomachinery shape optimization

The application of a three-dimensional (3D) inverse design method in which the blade geometry is computed for a specified distribution of circulation to the design of turbomachinery blades is explored by using two examples. I n the first instance the method is applied to the design of radial and mixe d flow impellers to suppress secondary flows. Based on our understanding of the fluid dynamics of the flow in the impeller, simple guidelines are deve loped for input specification of the inverse method in order to systematica lly design impellers with suppressed secondary flows and a more uniform exi t flow field. In the second example the method is applied to the design of a vaned diffuser. Again based on the understanding of the detailed Row fiel d in the diffuser obtained by using 3D viscous calculations and oil flow vi sualizations, simple design guidelines are developed for input specificatio n to the inverse method in order to suppress corner separation. In both cas es the guidelines are verified numerically and in the case of the diffuser further experimental validation is presented.