Tech Briefs

Predicting Flutter and Forced Response in Turbomachinery

TURBO-AE is a computer code that enables detailed, highfidelity modeling of aeroelastic and unsteady aerodynamic characteristics for prediction of flutter, forced response, and bladerow interaction effects in turbomachinery. Flow regimes that can be modeled include subsonic, transonic, and supersonic, with attached and/or separated flow fields. The three-dimensional Reynolds-averaged Navier-Stokes equations are solved numerically to obtain extremely accurate descriptions of unsteady flow fields in multistage turbomachinery configurations. Blade vibration is simulated by use of a dynamic-grid-deformation technique to calculate the energy exchange for determining the aerodynamic damping of vibrations of blades. The aerodynamic damping can be used to assess the stability of a blade row. TURBO-AE also calculates the unsteady blade loading attributable to such external sources of excitation as incoming gusts and blade-row interactions. These blade loadings, along with aerodynamic damping, are used to calculate the forced responses of blades to predict their fatigue lives. Phase-lagged boundary conditions based on the direct-store method are used to calculate nonzero interblade phase-angle oscillations; this practice eliminates the need to model multiple blade passages, and, hence, enables large savings in computational resources.

This program was written by Dale E. VanZante and John J. Adamczyk of Glenn Research Center; Rakesh Srivastava, Milind A. Bakhle, and Aamir Shabbir of the University of Toledo; Jen-Ping Chen and J. Mark Janus of Mississippi State University; Wai-Ming To of AP Solutions, Inc.; and John Barter of GE Aircraft Engines. For further information, access the Technical Support Package (TSP) free online at www.techbriefs.com/tsp under the Software category.

Inquiries concerning rights for the commercial use of this invention should be addressed to NASA Glenn Research Center, Commercial Technology Office, Attn: Steve Fedor, Mail Stop 4–8, 21000 Brookpark Road, Cleveland, Ohio 44135. Refer to LEW-17514-1.

This Brief includes a Technical Support Package (TSP).

Predicting Flutter and Forced Response in Turbomachinery ; (reference LEW-17514-1) is currently available for download from the TSP library.

Please Login at the top of the page to download.