FLUTTER ANALYSES VIA DIFFERENT SOLVERS AND VALIDATION WITH EXPERIMENTAL DATA
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
With the desire of increasing the performance and power to weight ratio (for aero engines), the gas and steam turbine blades are becoming slimmer and exposed to higher loads. Together with this, different physics underlying the blade failures became stimulated. Flutter is one of the instabilities that lead failure and design against flutter is still a challenge. Validated, trustable Computational Fluid Dynamics (CFD) tools are believed to be the ultimate key towards the design of flutter-free turbomachines.
This work is dedicated to flutter analyses via different CFD solvers and comparison of the calculated results with the experimental data. The experimental data was produced in previous studies with the flutter test rig situated at The Royal Institute of Technology (KTH). This test rig is a unique, controlled flutter testing setup with an annular cascade.
Classical time marching approach (influence coefficients-INFC) and Transient Blade Row (TBR) approach (traveling wave mode-TWM) in ANSYS-CFX are tested in this study. Also some comparisons are made between these and in-house harmonic solver TF3D.
From the steady state perspective there are two design and two off-design operating points. In addition to this, three different reduced frequencies and three different oscillation modes (axial, circumferential, torsion) make up nine unsteady operating points. A number of combinations of the steady and unsteady operating points are investigated.
INFC and TWM results are compared with the experimental data at 10, 50 and 90% spans in terms of unsteady Cp properties (phase and amplitude) around the blade circumference. Finally, the stability curves obtained via INFC are compared on their own to point out operational differences. Stability curves for a selected operating point from INFC, TBR (TWM) are compared.
Place, publisher, year, edition, pages
2013. , 76 p.
Fluid Mechanics and Acoustics Aerospace Engineering Energy Engineering
IdentifiersURN: urn:nbn:se:kth:diva-137321OAI: oai:DiVA.org:kth-137321DiVA: diva2:678761
Master of Science - Turbomachinery Aeromechanic University Training
2013-09-27, KTH-Heat and Power Generation Department, 13:00 (English)
Glodic, Nenad, PhDMayorca, Maria, PhD
Laumert, Bjorn, Lecturer
ProjectsFUTURE (Flutter-Free Turbomachinery Blades)