TRANSONIC FLUTTER OF HYPERSONIC SKIN-PANELS
Abstract
Strict low-weight requirements and large thermal loads characterizing the hypersonic flight result in skin-panels with reduced stiffness, thus prone to deformations and structure insta- bility. In this scenario, an optimal distribution of thermal protection systems (TPS) and an appropriate choice of skin-panel support can significantly reduce the structural weight, thus maximizing payload while ensuring aircraft survivability. A typical approach employed by single-stage-to-orbit (SSTO) spaceplanes such as Skylon and HOTOL, consists in separating thermal-shield material from load-bearing structure. In this case, the "floating" skin-panels only absorb the thermal loads while transmitting the aerodynamic loads to the underlaying ultra-light composite structure through a number of posts. The presence of thermal loads certainly makes hypersonics the harshest regime under an aerothermoelastic point of view; However, it is not clear if a structural design optimized for hypersonic speeds will still present satisfactory performance in the transonic regime, where flutter margins are typically at a minimum and numerical simulations often fail in predicting flutter during the flight tests. The experiments will be conducted in the NCKU Transonic Wind Tunnel facility, capable of providing a freestream Mach number between 0.8 and 1.2. The basic set-up will consist of an aeroelastically scaled panel hinged at the corners by four posts. Successive tests will employ a series of panels supported in the same fashion in order to assess the level of constructive and destructive interactions among panels undergoing flutter. Mass distribution will be altered by the addition of lumped loads to model the presence of thermal insulation layers. The simulation of the experiment will improve the fidelity of existing low-fidelity models and numerical simulations.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 04, 2023
- Source ID
- FA23862114118
Entities
People
- Gaetano Currao
Organizations
- Air Force Office of Scientific Research
- National Cheng Kung University
- United States Air Force