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Transient Aerothermoelastic Experimental Response of a Full-Scale Curved Panel

Description:

TECHNOLOGY AREA(S): Air Platform

OBJECTIVE: Produce validation data for transient aerothermoelastic effects in high-fidelity coupled fluid-thermal-structure CFD modeling and simulation tools from a ground test of a full-scale curved panel in hypersonic flow.

DESCRIPTION: The extreme environmental conditions experienced in hypersonic flight can cause structural deformations and unsteady responses. Furthermore, the heating rates and maximum temperatures can vary significantly over the surface of a vehicle. Temperature gradients can also exist through the vehicle skin. This topic aims to fund an experiment that characterizes the fluid-thermal-structure coupling of a full-scale curved panel at hypersonic speeds. Similarity laws should be taken into consideration for aerodynamic pressure, aerodynamic heat transfer, conduction, stresses, and deflections; trade-offs between scaling to realistic flight conditions and obtaining a transient response should be discussed.

A validation-quality dataset of a coupled fluid-thermal-structure experiment of a full-scale curved panel is sought. In particular, curved panels that are subsections of conic or bi-conic test articles are desired and documented sufficiently for reproduction in a physical or numerical experiment. The panel should be designed to incorporate state-of-the-art integrated sensors for the measurement of its structural response (e.g., accelerations, deflections) as well as provide information about the surface quantities relevant to the aerodynamic (e.g., pressure, skin friction) and thermal environments (e.g., surface temperature, heat flux, temperature gradients).

Flowfield visualization in the vicinity of the panel at multiple azimuthal locations is needed for CFD validation. High-speed PIV is preferred, but Schlieren and other shockwave visualization methods are also desired. Furthermore, the upstream flowfield must be characterized sufficiently for follow-on modeling and simulation validation as well (e.g., freestream turbulence intensity, inlet asymmetries, and boundary layer effects). Test facilities that use air as the working fluid are preferred, but inert gases are also acceptable.

PHASE I: Design aerothermoelastic experiment including geometry, materials, instrumentation, test facilities, and parameter space of interest. Produce test plan capable of obtaining physical quantities required to characterize the transient response of test article, including test facility boundary conditions, and identify hardware and instrumentation required to measure those quantities accurately.

PHASE II: Demonstrate that measurements taken are sufficient to fully characterize the aerothermoelastic response of panel. Demonstrate that test procedures and methodologies are applicable to general class of this configuration. Deliverables include documentation of as-tested experimental design, experimental findings,conclusions, and all data required to independently reproduce validation data in a similar facility. Demonstrate and deliver models and documentation at an Air Force facility.

PHASE III DUAL USE APPLICATIONS: Follow-on test funded by US DoD or prime contractors using the methodology is desired to verify its applicability to more general or point designs. USAF encourages the patent and licensure of any or all technology derived from this effort and to seek collaboration with prime contractors.

REFERENCES:

    • Zuchowski, B., “Predictive Capability for Hypersonic Structural Response and Life Prediction, Phase 1 – Identification of Knowledge Gaps,” Air Vehicles Integration and Technology Research (AVITAR), AFRL-RB-WP-TR-2010-3069, 2010.

 

    • Thornton, E. A., Dechaumphai, P., “Coupled Flow, Thermal, and Structural Analysis of Aerodynamically Heated Panels,” Journal of Aircraft, Vol. 25, No. 11, pp. 1052-1059, 1988.

 

    • Calligeros, J. M., Dugundji, J., “Similarity Laws Required For Experimental Aerothermoelastic Studies Part 2 – Hypersonic Speeds,” Office of Naval Research, Technical Report 75-2, DTIC AD253970, 1961.

 

  • Brooks, J. M., Gupta, A. K., Smith, M. S., Marineau, E. C., “Development of Particle Image Velocimetry in a Mach 2.7 Wind Tunnel at AEDC White Oak,” AIAA Paper 2015-1915, 53rd AIAA Aerospace Sciences Meeting, 2015.

KEYWORDS: Aerothermoelasticity, hypersonic, wind-tunnel testing, flow visualization, structural dynamics, high-temperature materials, flutter, limit-cycle oscillation, fluid-thermal-structure interaction

  • TPOC-1: Daniel Reasor
  • Phone: 850-882-8221
  • Email: daniel.reasor@us.af.mil
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