Theoretical and Experimental Method for Determining Flow and Structural Response of Parafoil Models

Abstract

The experimental study of parafoil structures is not an easy task, as the properties of the model make testing uncertain and imprecise. Parafoils are structures characterized by their non-linearity, the flexibility of their materials, and a shape that is determined by the surrounding flow field. In order to continue the development of these structures, new methods to make testing more precise have to be developed. It is for this reason that in this thesis, the method for determining full flow and structural response of parafoil models was proposed. The method is based on a fluid-structure interaction FSI analysis, which was carried out in different models for several angles of attack. The models varied from simpler two-dimensional geometries to a three-dimensional wing that resembled a parafoil. In the present study, experimental measurements were replicated with numerical simulations. Using ANSYS Fluent, an analysis of airflow around a wing model was carried out, and load and moment coefficients, and pressure distributions were obtained. Using ANSYS Static Analysis and the load distributions previously obtained, deformations stresses and strains of the wing model were calculated. Several points of the structure were selected and the data was compared to the one obtained by replicating the strain gauges and deformation sensors placed on the physical model. By solving an optimization problem, the experimental angle of attack was found. This procedure was carried out in different scenarios, including the simulation of measurement noise.