DESIGN AND OPTIMIZATION OF COMPOSITE VESSEL FOR HYDROGEN STORAGE SUBJECT TO INTERNAL PRESSURE & IN-FLIGHT LOADS

The wide range of applications for civilian UAVs, will open up a variety of markets for potential sales and economic growth. The Scientific Community could benefit in many ways from employing UAVs in the civilian sphere. A research is being carried out aiming at the design of Very-Long Endurance Solar Powered Autonomous Stratospheric UAV. It could play the role of a pseudo satellite, with the advantage of allowing a more detailed land vision due to the relative closeness to the land (17-20 km) and at cost much less than real satellite. Two different configurations, as shown in fig (1), are under investigation in order to understand the best solution that completely fulfil the a priori imposed constraints. In recent years, an increasing interest of aeronautical community is focused on design of solar powered platforms and zero emission airplanes by using a coupled system (solar array and hydrogen fuel cells) to supply energy during whole day in order to ensure the capability of continuous flight for several months. As is known , the fuel cells system, require at least a couple of external tanks for fuel storage. The storage of hydrogen and oxygen is done using pressure vessel installed inside the wing. In this fashion, they are subjected not only to pressure loads but also to in-flight loads that may abruptly change the optimum layup required to satisfy regulation requirements. A parametric analysis is performed to define the optimum layout and number of tanks to supply the required power. In addition a genetic algorithm is used to optimize the laminate layup in order to reduce the weight of tank and ensure the capability to resist without catastrophic failure.