MODELING SURFACE VARIATION AND ASSESSMENT OF ITS IMPACT ON AERODYNAMIC PERFORMANCE IN TURBOMACHINERY APPLICATIONS

摘要

Analyzing the impact of manufacturing variability on the performance of turbomachinery components supports two critical dimensions in the product life cycle. It provides a technological process to decide on the criterion of acceptability of the deviated manufactured component based on the performance assessment andsecondly,provides sensitivity of the geometrical variation to the component performance to build a robust design space. Currently, non-deterministic methods based on probability distribution function of the design parameters are used to assess the impact of variability, and the output is presented as a set of correlation coefficients linking the geometrical parameters to the component performance. Though these methods provide adequate information on the robustness ofthe design space, the amount of computational requirement and lack of consideration of the local effect of geometry modification on the performance pose challenges. In the current work, the method presented is based on a variant of radial bas is functions to construct the deviated manufactured geometry of the turbine rear frame (TRF) of a modern gas turbine engine for aerodynamic as sessment. The approach is used to accurately and rapidly construct a 3D deviation map from a set of discrete measured data using a coordinate measuring machine (CMM). Additionally, the developed approach is usedas a method of applying free-form deformation in the critical localities on the aerodynamic surface identified using the sensitivity information from an adjoint analysis to re-design the baseline geometry. Aerodynamic analysis is conducted to understand the nature of geometry change due to the manufacturing variation and explain the mechanismofperformance change.