Transonic Flutter of Hypersonic Skin-Panels
Abstract
This work is a numerical and experimental study of transonic panel flutter where alternative boundary conditions are explored. Hypersonic vehicles are subjected to strict low-weight requirements, thus skin-panel configurations are often optimized to maximize the payload. In the case of Skylon, a single-stage-to-orbit concept vehicle, one of these configurations involves the use of a series of discrete supports to stiffen thinner skin-panels, thus the question arises of whether this configuration offers improved stability margins also in the transonic regime. The geometrical boundary conditions are herein idealized as a rectangular panel clamped on all sides and with a rigid pin located in the middle. A numerical parametric analysis was conducted for a steel skin-panel for a range of altitude and Mach numbers to quantify the benefits of this panel configuration in the transonic, supersonic and low-hypersonic regime. A panel clamped on all sides and with a pin in the center was also tested in the transonic wind tunnel, where time-accurate displacement measurements were performed using laser sensors. The analysis of experiments and numerical simulations shows that transonic flutter is actually a forced response to an unsteady aerodynamic-load, rather than a two-way fluid-structure interaction. Higher natural modes, with a frequency close to the aerodynamic fluctuating pressure, are directly excited. Generally, the additional constraint in the center does not seem to add significant benefits in terms of dynamic stability in the transonic regime. Numerical results also suggest that the pin has a destabilizing effect at medium-low altitudes in the hypersonic regime. Conversely, flutter was successfully delayed in the supersonic regime.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 04, 2024
- Accession Number
- AD1228849
Entities
People
- Chih-yung Wu
- Gaetano Currao
- Kung-ming Chung
- Wen-lih Chen
- Zu P. Tan
Organizations
- National Cheng Kung University