Browsing by Author "Bezuidenhout, Bradley"

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    Design methodology for an inflatable membrane aerofoil using numerical shape optimisation
    (Stellenbosch : Stellenbosch University., 2020-04) Bezuidenhout, Bradley; Venter, Gerhard; Venter, Martin P.
    ENGLISH ABSTRACT: The use of inflatable wings for unmanned aerial vehicles over their fixed-winged counterparts has many advantages such as the wing’s ability to be folded up when deflated, this saves storage space. However, there are challenges associated with predicting the profile of the inflatable wing, which makes achieving a desirable aerofoil profile non-trivial. This research aimed to formulate a design methodology which would determine the uninflated geometry for an inflatable aerofoil profile, accurately fitting that of a target, prescribed aerofoil profile. The uninflated geometry can then be used to construct a physical model. The methodology involved performing numerical shape optimisation on finite element models. Once the methodology had been established, its robustness was tested by utilising numerical models with differing numbers of inflation cavities, altering the thickness of the target aerofoil profile as well as increasing its complexity. For each case, the methodology successfully satisfied its aim, producing accurate fits between the inflated numerical model and the target aerofoil profile. When fitting a fifteen cavity numerical model to a NACA 0030 aerofoil, an R2 fit of 0 .990 was achieved. When validated, the inflated shape of the numerical model proved to predict that of its corresponding physical model accurately. For an eight cavity model, the fit between the physical and numerical model produced an R2 value of 0.988. Future work should focus on a more comprehensive material model that will allow for a larger load-bearing capacity of the inflated structure.