Accession Number : AD1019750

Title :   Real-Time Wing-Vortex and Pressure Distribution Estimation on Wings Via Displacements and Strains in Unsteady and Transitional Flight Conditions

Descriptive Note : Technical Report


Personal Author(s) : Masarati,Pierangelo ; Alioli,Mattia ; Morandini,Marco ; Carpenter,Trenton ; Osterberg,N B ; Albertani,Roberto

Full Text :

Report Date : 07 Sep 2016

Pagination or Media Count : 40

Abstract : The analysis of thin structural components, which are characteristic of a broad class of Micro Air Vehicles, is presented herein. A direct solutionapproach in co simulation with fluid-dynamics solvers is used. An original variational formulation is developed for the inverse problem ofreconstructing full-field structural displacement and pressure distribution of membrane wings subjected to static and unsteady loads frommembrane strain distribution. Moving Least Squares are used to smooth and remap surface strain measurements, estimated from Digital ImageCorrelation (DIC), as needed by the inverse solution meshing. The same approach is used to map the structural and fluid interface kinematicsand loads during the fluid structure co-simulation. The inverse analysis is verified by reconstructing the deformed solution obtained with acorresponding direct formulation, based on nonlinear membrane structural analysis implemented in a free general-purpose multibodydynamics solver and tightly coupled in co-simulation with a CFD solver. Both the direct and the inverse analyses are validated by comparingthe direct predictions and the reconstructed deformations with experimental data for prestressed rectangular membranes subjected to staticand unsteady loads. The load distributions reconstructed using the inverse analysis are compared with the corresponding ones obtained usingthe direct analysis. The inverse analysis runs on standard off the-shelf PCs and can be implemented in real-time, providing load distributionestimates at a rate in the order of tens of datasets per second.

Distribution Statement : APPROVED FOR PUBLIC RELEASE