Publications

Hydrogen has been identified as a potential fuel for air transportation without carbon emissions. Hydrogen contains much higher energy per unit mass than any conceivable rechargeable battery, potentially making longer-range missions possible than pure electric configurations. However, hydrogen’s low volumetric energy density presents practical challenges. Hydrogen must either be kept under deep cryogenic conditions or compressed under very high pressure. Either solution is likely to require adding significant drag and tank weight to the airplane. This is a packing optimization problem subject to aerostructural physics, and we can employ multidisciplinary design optimization techniques to provide insight into optimal wing design for novel hydrogen aircraft concepts. In this paper, we extend prior work on wing packing optimization subject to aerodynamics only, and now incorporate structural analysis and structure geometry into the problem. We optimize the range of a hydrogen-electric aircraft with hydrogen fuel storage located inside the wing outer mold line. The geometry of the hydrogen storage tanks influences the shape of the wing as well as the weight and volumetric capacity of the tank. While the effect of hydrogen storage on other aircraft concepts cannot be generalized from this study, the optimization methods we use are promising for performing relevant aircraft design trade studies. The optimizer finds the correct tradeoff between weight, drag, and fuel storage for the mission, subject to spatial integration feasibility. In our test scenario, we find that the optimal aerostructural design involves substantial wing root thickening.