The modern development in design of airships and aerostats has led to unconventional configurations quite different from the classical ellipsoidal and spherical ones. This new class of air-vehicles presents a mass-to-volume ratio that can be considered very similar to the density of the fluid displaced by the vehicle itself, and as a consequence, modeling and simulation should consider the added masses in the equations of motion. The concept of added masses deals with the inertia added to a system, since an accelerating or decelerating body moving into a fluid displaces a volume of the neighboring fluid. The aim of this paper is to provide designers with the added masses matrix for more than twenty Lighter Than Air vehicles with unconventional shapes. Starting from a CAD model of a given shape, by applying a panel-like method, its external surface is properly meshed, using triangular elements. The methodology has been validated by comparing results obtained with data available in literature for a known benchmark shape, and the inaccuracies of predictions agree with the typical precision required in conceptual design. For each configuration, a CAD model and a related added masses matrix are provided, with the purpose of assisting the practitioner in the design and flight simulation of modern airships and scientific balloons.

This paper presents a conceptual design of a satellite device to be used for capturing asteroids, based on inflatable structures. The mission requirements, the conceptual design, the methodology for the selection of the best solution, and simulations for the preliminarily structural analysis of the device are described within. Several finite element analyses have been carried out in order to find the best strategy to model flexible materials under internal pressure, and the device structure has been changed accordingly in order to obtain the best trade-off between weight and strength. This paper presents the sizing and the weight breakdown of the satellite inflatable components, which are quite complex to model with regards to the structural simulation. The results obtained seem to confirm the feasibility of such a structure and motivates further studies and experimental tests.

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