Validation of Time Domain Flutter PredictionTool with Experimental Results

Sammanfattning: In turbomachinery applications as propulsion and power generation, there is a continuous endeavour to design engines with higher efficiency, driving the compressor and turbine blades towards slimmer and more aerodynamically loaded configurations that frequently operate with fluids at higher temperatures and speeds. This combination of reduced design space and adverse operating environment makes the blades more susceptible to flutter and challenges the designer to predict its occurrence. Nowadays there are different CFD solvers that allow the prediction of flutter in turbomachinery; some of them are more efficient than others and provide considerable computational power savings when compared with traditional CFD methods that sometimes require the simulation of several or all the blades in a given row. The present thesis work is aimed at investigating the strengths and potential limitations of a novel time marching method for Flutter prediction in the Travelling Wave Mode (TWM) domain available in ANSYS CFX 14.5. The results are compared with experimental measurements obtained at the KTH test rig and CFD simulations in the Influence Coefficient Domain (INFC) performed in a previous MSc. Thesis in 2013. An approach in CFX to solve flutter is the Fourier Transformation method that uses only two passages with phase lagged periodic boundary conditions. In the previous thesis only one operating point was calculated using this method. This project focuses on the extension of the calculations to various operating points and expanding the solver validation.