Examination of Three-Dimensional Flow over a Chambered Inflatable Wing

摘要

Inflatable wings provide a compact alternative for aircraft that need to fit into small volumes before deployment, such as backpack unmanned aircraft or rocket-delivered air vehicles. Common inflatable designs use inflation chambers separated by spanwise baffles, generating a naturally undulating airfoil surface. Early wind tunnel tests of these designs showed evidence that separation over these airfoils was reduced compared to their smooth counterparts. Subsequent efforts to replicate these advantages computationally have proven ambiguous-while under certain conditions the inflatable airfoil may improve the lift-to-drag characteristics of the wing, in other conditions the inflatable profile appears detrimental. Currently, these wings are being investigated through a combination of two-dimensional and three-dimensional simulations and physical experiments. The initial targets of these comparisons are moderate Reynolds number (～10~5) flows, comparable to known flight conditions of inflatable wing UAVs. This places the flows in a naturally transitional regime, presenting additional complications in attempting to reconcile the results for these different investigative techniques.