Impact of Structural Damping Nonlinearity in Transonic Limit Cycle Oscillations (LCO)
Abstract
The focus of this research has been on the assessment of the effects of internal friction on the response of aeroelastic systems exhibiting either explosive flutter or limit cycle oscillations to provide a confirmation of the potential of friction as a significant stabilizing factor in the limit cycle oscillations observed on several aircraft, e.g. F- 16. The work performed in this regard can broadly be divided into three major efforts, two computational/ theoretical and one experimental: (1) the analysis of the effects of friction on a structural dynamic systems in which the effects of the aerodynamic forces have been modeled. The computational expediency of this simple model allowed to analyze and study a vast array of cases from which broad conclusions were derived the validity of which was later extended to the complex models of task (2). (2) the analysis of the effects of friction on actual aeroelastic systems, i.e. airfoil and flat plate in a uniform flow, in which the aerodynamic forces are computed in time in parallel to the structural dynamic analysis in a tight coupling format. (3) the experimental testing in the DLR- Gottingen (Germany) Transonic wind tunnel of a NLR7301 airfoil equipped with a friction device similar to the ones studied in tasks (1) and (2). This effort was followed by a data analysis that revealed mostly similarities, albeit a few differences, with the theoretical results of tasks (1) and (2) above.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2005
- Accession Number
- ADA439001
Entities
People
- Danny D. Liu
- Marc P. Mignolet
Organizations
- Arizona State University