<p>An efficient method is developed to efficiently predict the effect of blend repairs on airfoil frequencies, modal assurance criterion (MAC), and mode shape displacement vectors. The method is demonstrated on blade-only model of a transonic research rig compressor rotor airfoil. A subset of the blend repair design space is sampled to provide training data to a Guassian Stochastic Process regressor. Each training point finite element mode (FEM)&nbsp;is constructed using a parametric definition of blend repair surface. This blend repair surface is used to modify the airfoil surface definition and a mesh morphing process is used to modify the nominal FEM to the repaired configuration. The scalar frequencies and MAC values are emulated directly, but the mode shape vectors are transformed into a reduced basis space. The coefficients of this reduced basis are emulated directly and used to to re-expand the vectors to for full blended airfoil mode shape reconstruction. Emulator fit is determined with leave one out validation and it is found that large variations in modal properties from large blend repairs can be accurately emulated with a reasonable number of training points. Two high frequency modes are found to challenge emulator quality because of the interaction of closely spaced modes.</p>

Gaussian Stochastic Process Modeling of Blend Repaired Airfoil Modal Response Using Reduced Basis Mode Shape Perturbations

Paper Proceedings: https://asmedigitalcollection.asme.org/GT/GT2021/volume/84898

Turbo Expo 2021

Supporting the need among researchers worldwide for additional online and multimedia content, ASME now offers the ASME Conference Video Collection. This platform will collect and provide long-term access to conference presentation videos, encompassing all technology areas within ASME's technical conference and events program. About 30,000-40,000 engineers across all mechanical engineering and related disciplines participate in ASME conferences each year. This includes authors of approximately 6,000 to 8,000 technical papers published by ASME, the majority of whom also submit video presentations for our virtual conferences. The video collection will be available as an add-on to existing product packages or as a separate subscription.