Computational fluid dynamics and fluid structure interaction analysis on the use of inflatable wing structures
The research conducted in this thesis was done to ascertain the potential of using drop-stitch panels for inflatable wing designs. This was done primarily by using 2D CFD analysis on airfoil sections approximating the shape of a drop-stitch panel to analyze the lift and drag performance of the panel. ANSYS Fluent and Star-CCM+ was the CFD software packages used in this study. The aerodynamic performance of the drop-stitch panel were found to be suboptimal in comparison to more traditional airfoil designs, such as the NACA 0012 and 4415, both in L/D ratio and stall characteristics. Modifications to the panel shape, in the form of foam or fabric additions, were also tested in CFD in an attempt to improve the panel airfoil. Overall, these additions did improve the L/D performance slightly, and in some cases the stall characteristics. Despite this the L/D ratio still did not approach that of the NACA airfoils, highlighting the major drawback of the drop-stitch panel: its inability to have thickness variation due to a manufacturing limitation. A proof-of-concept FSI analysis was also conducted to examine the validity of using this model on inflatable wing designs. The tests found that it is feasible to simulate the deformation of a flexible surface using internal pressurization, and that the flow will interact and further deform the material. The study also found that the increase of flow velocity over a bump in a flexible surface further displaces that surface into the flow due to the pressure drop caused by the increased dynamic pressure over that portion of the surface. This FSI model can be used in future test cases for inflatable wing flow deformation analysis.