Aerodynamic Drag Characteristics of Miura-Ori Composite Structure

Miura-ori is a form of origami and is widely used in aerospace. The aerodynamic characteristics of Miura-ori composite structure are greatly influenced by its configuration. In this paper, the aerodynamic performance of Mirua-ori sheet in different deployable configurations is studied. Through the analysis of a three-dimensional model of Miura-ori sheet, it is found that the largest pressure is on the foremost crease of Miura-ori sheet, which is prone to failure. A two-dimensional model can be used to refine the analysis of the special orientation of this crease. Next, the aerodynamic characteristics of the sheet with and without grooves are studied, with results showing the former can significantly reduce drag. Then, the aerodynamic characteristics of the grooves with holes are studied, and it is found that holes in the front wall increase the drag and holes in the rear wall reduce the drag. Finally, the arrangement and combination of grooves with different apex angles are studied. It is found that the model with the shape of a check sign has the best drag reduction, which is due to a large separation vortex formed in the upper part. During the negative pressure landing of the airship, the internal pressure is relatively low, and when the wind speed is high, it is prone to local snap-through instability and global collapse (contact and squeeze) instability. The adjustment of drag force through reconfiguration of origami is of great significance to the study of shape retention and stability of stratospheric airship envelopes.