Free-flight force and moment measurement in hypersonic impulse facilities using multi-camera telecentric visualization and massively parallel scene reconstruction
Abstract
We will develop a comprehensive methodology for highly accurate force and moment measurements on free-flight models in short-duration hypersonic facilities. Although forces and moments are basic and important aerodynamic quantities, their measurement in such facilities has traditionally been difficult, as their short test times preclude the use of conventional force balances. Balance modifications to account for these brief time scales require complex models and calibration procedures; free-flight techniques provide an attractive alternative, but in previous implementations have suffered from limited accuracy and/or flexibility. Our proposed approach will provide a revolutionary step forward for free-flight testing. Massively parallel, GPU-enabled ray-tracing applied to high-fidelity CAD geometries will be used to reconstruct pixel intensities near the visualized model outline, mimicking the physical process by which images are formed; these pixel intensities will be compared with those in high-speed experimental images obtained using a novel, multi-camera telecentric visualization system, allowing iteration to best-fit model-pose parameters. This approach will provide complete flexibility in model geometry and quantity, while accuracy will be at least an order of magnitude superior to alternative optical-tracking approaches, enabling accurate 6 degree-of-freedom recovery of forces/moments (less than one percent) even on sub-millisecond time scales. The developed software will be applicable to any problem requiring accurate, nonintrusive tracking of one or multiple objects. A rapid-acting, electromagnetically actuated release system will also be designed and fabricated, and the full methodology will be demonstrated at various hypersonic facilities nationwide.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 09, 2023
- Source ID
- W911NF2110338
Entities
People
- Stuart Laurence
Organizations
- Army Contracting Command
- Defense Advanced Research Projects Agency
- University of Maryland