Periodic trim solutions with hp-version finite elements in timeFinite elements in time as an alternative strategy for rotorcraft trim problems are studied. The research treats linear flap and linearized flap-lag response both for quasi-trim and trim cases. The connection between Fourier series analysis and hp-finite elements for periodic a problem is also examined. It is proved that Fourier series is a special case of space-time finite elements in which one element is used with a strong displacement formulation. Comparisons are made with respect to accuracy among Fourier analysis, displacement methods, and mixed methods over a variety parameters. The hp trade-off is studied for the periodic trim problem to provide an optimum step size and order of polynomial for a given error criteria. It is found that finite elements in time can outperform Fourier analysis for periodic problems, and for some given error criteria. The mixed method provides better results than does the displacement method.
Document ID
19920064307
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Hou, Lin-Jun (NASA Langley Research Center Hampton, VA, United States)
Peters, David A. (Georgia Institute of Technology Atlanta, United States)
Date Acquired
August 15, 2013
Publication Date
January 1, 1991
Subject Category
Aircraft Stability And Control
Meeting Information
Meeting: AHS International Specialists'' Meeting on Rotorcraft Basic Research