Robust optimization design of compressor blade considering machining error

The machining error is inevitably produced during the actual manufacturing process of the compressor blade, which leads to the degradation of the aerodynamic performance to some extent. In order to reduce the influence of the machining error, this paper carried out a research on the robust optimization design considering manufacturing error. Scheme of optimization design in this paper is more economical than the scheme of directly increasing the manufacturing precision. The controlled diffused airfoil in the research is parameterized by the application of Non-Uniform Rational B Spline (NURBS) curve. A coordinate measuring machine is used to obtain the distribution of the machining error uncertainty. To ensure the high efficiency of the robust design, the uncertainty quantification is made by using the method of Non-intrusive polynomial chaos (NIPC) expansion. In the key nodes of NIPC, several surrogate models are established based on Latin Hypercube Design (LHD) + Kriging, which further reduces the costs of optimization design. Finally, a new design framework has been established and the optimization design has been made successfully. Under the condition of the machining accuracy unchanged, it reduces the sensitivity of aerodynamic performance to the machining error, and increases its stability.