Research on disruptive design pre-identification in the preliminary design phase of aero engine flow pass multidisciplinary optimization

In aero engine design, determining whether the preliminary design will have disruptive effects on the detailed design is the key to multidisciplinary design optimization in the preliminary design stage. In order to adapt to the non-orthogonal parameter value range caused by the selfconstrained parametric modeling method, a non-orthogonal space mapping method that maps the optimal Latin hypercube sampling points of the traditional orthogonal design space to the non-orthogonal design space is proposed. Based on the logical regression method in machine learning field, a kind of feasible domain boundary identification method is employed to identify whether the sample spatial response meets the relevant criteria. The method proposed in this paper is used to identify and analyze the key technologies of the high-pressure turbine mortise joint structure. It is found that the preliminary design of the aero engine may lead to the failure to obtain a mortise joint structure meeting the design requirements in the detailed design stage. The mortise joint structure needs to be pre-optimized in the preliminary design stage.

Multi-scale thermodynamic analysis method for 2D SiC/SiC composite turbine guide vanes

Ceramic Matrix Composite(CMC) turbine guide vanes possess multi-scale stress and strain with inhomogeneity at the microscopic scale.Given that the macroscopic distribution cannot reflect the microscopic stress fluctuation, the macroscopic method fails to meet the requirements of stress and strain analysis of CMC turbine guide vanes.Furthermore, the complete thermodynamic properties of 2 D woven SiC/SiC-CMC cannot be obtained through experimentation.Accordingly,a method to calculate the thermodynamic properties of CMC and analyze multi-scale stress and strain of the turbine guide vanes should be established.In this study, the multi-scale thermodynamic analysis is investigated.The thermodynamic properties of Chemical Vapor Infiltration(CVI) processed SiC/SiC-CMC are predicted by a Representative Volume Element(RVE) model with porosity, leading to the result that the relative error between the calculated in-plane tensile modulus and the experimental value is 4.2%.The macroscopic response of a guide vane under given conditions is predicted.The relative error between the predicted strain on the trailing edge and the experimental value is 9.7%.The calculation of the stress distribution of micro-scale RVE shows that the maximum value of microscopic stress, which is located in the interlayer matrix, is more than 1.5 times that of macroscopic stress in the same direction and the microscopic stress distribution of the interlayer matrix is related to the pore distribution of the composite.