Three-dimensional inverse method for aerodynamic optimization in compressor

Abstract

Design experience plays an important role in compressor design. Accumulated design experience is used to reduce the number of simulations and to make time for the whole optimization process to be compatible with industrial standards. However, the major drawbacks of this design strategy are that the design result depends on talented designers with rich design experience and this method does not easily produce better configurations than existing designs. These drawbacks are related to the parametric description of the blade, which is conventionally performed using only geometric parameters. A good solution to this problem is to use a blade parametrization based on an inverse design method. Inverse design methods have been widely used for the design of various kinds of turbomachines, proving that it is a valuable alternative to the iterative use of direct methods. One main design parameter in the inverse design approach is the blade loading on both the hub and the shroud along the meridional direction. The blade loading distributions have a more direct relationship to the aerodynamic performance because they influence the flow field in a more straight-forward way. Fewer design parameters are then required to describe the blade shape than a purely geometric expression of the blade. Therefore, an optimization design method using the inverse method to parameterize the blade geometry can reduce the overall optimization time. The optimization design process then gives the optimal blade loading distributions, instead of the optimal combination of the geometric parameters. This is a more general result which can be applied to similar design problems without repeating the optimization process.