<p>Despite decades of innovation in aerospace engineering, wing attachments – also known as stores – still pose a serious threat to the safety and performance of modern aircraft. For example, in fighter jets during normal operations, stores can induce unwanted limit-cycle oscillations [1], which are self-sustaining vibrations that the pilot feels as large lateral motions [2]. Previous studies on an experimental model airplane indicated that wing-based stores can drastically alter the global dynamics of the parent aircraft when coupling mechanism between the stores and the wings consist of strong nonlinearities [3]. Furthermore, this past research found that the effect on dynamics is dramatically different when two stores are active instead of only one. It has been hypothesized that when two stores are present, they interact destructively with each other and cancel out their individual effects. With this research, we investigated the effects of two strongly nonlinear attachments on the dynamics of a two-degree-of-freedom, coupled oscillator system that reproduced the behavior of the first two linear modes of the airplane. The research found that no store-to-store interactions arose in the reduced-order system; however, because this model did not incorporate the complete geometry, it did not conclusively confirm or deny the existence of store-to-store interactions in the model airplane. Consequently, since the reduced-order model did not conclusively answer the proposed hypothesis, a deeper study into the behavior of the model airplane with nonlinear stores is warranted. To this end, the next step is to construct a more representative model of the airplane that captures the geometry using finite elements.</p>

The Effect of Store-to-Store Energy Transfers on the Global Dynamics of Aircraft

Paper Proceedings: https://asmedigitalcollection.asme.org/IDETC-CIE/IDETC-CIE2021/volume/85369

ASME 2021 International Design Engineering Technical Conferences & Computers and Information in Engineering Conference (IDETC/CIE2021)

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