Turbomachinery component design by means of CFD

A short overview of the main techniques for turbomachinery blade design based on CFD is followed by a more detailed description on an Optimisation- and Inverse Design method, developed at the von Karman Institute. The optimisation method uses an Artificial Neural Network to extract knowledge from a Database containing the results of previous designs and a Genetic Algorithm to define the optimum blade. The inverse design method makes use of the Euler or Navier-Stokes equations to predict how a given 3D blade shape should be modified to reach a prescribed pressure or Mach number distribution along the blade surface. Examples of transonic compressor and turbine blades, designed by both methods, illustrate the potential of these modern aero-design systems. Special attention is given to the problems related to existence and uniqueness and to those features that facilitate the practical use of these methods.