Biomimetics in Airship Design

Many attempts have been made to mimic the movement of a fish in water in order to find novel solutions in autonomous underwater vehicles (AUV) [1-4]. Conventional airships are driven by propellers and steered by stabilizers with rudders or with thrust vector control. Such propulsion and steering systems are efficient only in a small range of operation. The goal of our project is to mimic the fish-like movement with an airship body in air. In a theoretical study [5] we have shown that a 6m long airship in air is similar to the trout in water. Therefore we want to build a geometrically similar body which mimics the body. motion of a trout in steady state swimming. The activation is realized using Dielectric Elastomers (DE), a promising class of Electroactive Polymers (EAP). The principles of biomimetics in structural design and propulsion are discussed in this paper. The similarity of the optimized solutions found by the evolution for animals living in water and an optimized design of an airship will be shown. In a next step, the design of an indoor-flying airship propelled by a fish-like motion is evaluated. Various development tests, including wind tunnel testing and flight trials were performed and the gained results will be presented. First computational fluiddynamic simulations performed have shown similar vortex flow fields. In addition. the average forces could be measured accurately in wind tunnel tests and will be used to dimensioning the activation of the fin appropriately. From these results a conclusion shall be drawn, how far biomimetics can be used successfully in the design of future airship. Fin Ray Effect®