Managing the lifecycle of the elements of a complex and safety-critical system, from conceptual design to support in operation, is still a relevant challenge in the industrial domain. Starting from research and engineering activities, up to production and delivery, the need of maintaining the trace of dependence, changes, and possible updates regarding the final product is a crucial aspect for success. Particularly, conceptual and preliminary design activities are affected by a high level of uncertainty and a certain degree of project instability, usually caused by the need to explore alternative solutions and variants. Different tasks are performed concerning the identification of system requirements, functional and physical behavior using model-based design (MBD), and model-based systems engineering, which, generally, are subjected to extensive trade studies aimed at identifying the best solution. In this context, this paper presents how model-based digital twin and threads concepts will likely change the way in which the MBD process is managed, overcoming the issues associated with federated IT infrastructures and with tools integration. Notably, lifecycle and nonlifecycle related interoperability aspects are described, with particular focus on the exploitation of standards for lifecycle collaboration and heterogeneous simulation. The design of an ice protection system for a regional aircraft is selected as case study, starting from the work performed by the authors within the EC-funded research project CRYSTAL.

The design of integrated and highly efficient solutions for thermal management is a key capability for different aerospace products, ranging from civil aircraft using hydrogen on board to miniaturized satellites. In particular, this paper discloses a novel numerical tool for the design and thermal performance assessment of heat pipes. To achieve this goal, a numerical Ansys Parametric Design Language code is set up to verify the effective subtractive heat flux guaranteed by the selected heat pipe arrangement. The methodology and related tool show their ability to provide good thermal performance estimates for different heat pipe designs and operating conditions. Specifically, the paper reports two very different test cases: (1) solid metal heat pipes to cool down the crotch leading-edge area of the air intake of a Mach 8 civil passenger aircraft, and (2) a copper-water heat pipe to cool down a Printed Circuit Board of a generic small LEO satellite. The successful application of the methodology and numerical code confirms the achievement of the ambitious goal of developing in-house tools to support heat pipe thermal performance prediction for the entire aerospace domain.

The design of a Control Maintenance system (CMs) for an airborne platform deeply deals with the mission, the on-board systems interfaces and the identification of their behaviour in operation. This paper describes how the Model Based Systems Engineering (MBSE) was applied to an industrial test case to perform the functional design of an innovative CMs to be integrated with the aircraft Fuel system (Fs). The impact of different approaches applied when modelling the two systems and their integration through the SysML was investigated. As the IBM Rational Rhapsody® tool was used, the Harmony® methodology was applied to the CMs, while a MBSE customized approach was implemented for the Fs, even to cope with some differences in coupling an avionic system to a physical one.

This paper discloses the architecture and related performance of an environment control system designed to be integrated within a complex multi-functional thermal and energy management system that manages the heat loads and generation of electric power in a hypersonic vehicle by benefitting from the presence of cryogenic liquid hydrogen onboard. A bleed-less architecture implementing an open-loop cycle with a boot-strap sub-freezing air cycle machine is suggested. Hydrogen boil-off reveals to be a viable cold source for the heat exchangers of the system as well as for the convective insulation layer designed around the cabin walls. Including a 2 mm boil-off convective layer into the cabin cross-section proves to be far more effective than a more traditional air convective layer of approximately 60 mm. The application to STRATOFLY MR3, a Mach 8 waverider cruiser using liquid hydrogen as propellant, confirmed that presence of cryogenic tanks provides up to a 70% reduction in heat fluxes entering the cabin generated outside of it but inside the vehicle, by the propulsive system and other onboard systems. The effectiveness of the architecture was confirmed for all Mach numbers (from 0.3 to 8) and all flight altitudes (from sea level to 35 km).