Performance Assessment of an Integrated Environmental Control System of Civil Hypersonic Vehicles

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)

Cooling system of STRATOFLY hypersonic vehicle: conceptual design, numerical analysis and verification

This paper describes the thermal design processes of STRATOFLY hypersonic vehicle cooling system showing either the methodology and the supporting FEM numerical simulations. It focuses on two different regions that are both subjected to severe overheating: air-intake leading edges and the combustion chamber. Final remarks on structure survivability are presented

Liquid Metals Heat-Pipe solution for hypersonic air-intake leading edge: Conceptual design, numerical analysis and verification

Embedded propulsion systems will allow future hypersonic aircraft to reach amazing levels of performance. However, their peculiar small-radius air-intake leading edges pose serious challenges from the aerothermodynamic, design, integration, and manufacturing standpoints. This paper discloses the methodology developed in the framework of the H2020 STRATOFLY project and specifically tailored to support the conceptual and preliminary design phases of future high-speed transportation systems. The methodology implements an incremental approach which includes multifidelity design, modelling and simulation techniques. The specific application to the MR3, a Mach 8 waverider configuration with an embedded dorsal mounted propulsive subsystem, is reported. Different alternative solutions have been thoroughly analysed, including five liquid metals as fluids (Mercury, Cesium, Potassium, Sodium and Lithium) and relative wick and case materials (Steel, Titanium, Nickel, Inconel® and Tungsten) and three leading-edges materials (CMC, Tungsten with low emissivity painting and Tungsten with high emissivity painting). The analysis of the heat transfer limits (the capillary, entrainment, viscosity, chocking and boiling limits) carried out for all five fluids and relative compatible materials, together with a more accurate FEM analysis, suggest the adoption of a Nickel- Potassium liquid metal heat pipe completely integrated in a platelet air-intake leading edge made of CMC material. Ultimately, the effectiveness of the adopted solution throughout all mission phases has been verified with a detailed numerical model, built upon an electrical analogy

Thermal Protection System preliminary design of STRATOFLY high-speed propelled vehicle

This paper discloses the methodology and the preliminary results achieved in the framework of the H2020 STRATOFLY Project on the design of the Thermal Protection System of the MR3 vehicle. The results of the aero-thermal assessment performed throughout the trajectory clearly indicate the air-intake leading edges as the most critical area, thus dedicated Thermal Protection System alternatives have been explored. Specifically, solutions coupling high-temperature materials (mainly CMC and tungsten with different emissivity paints) with Liquid Metals Heat Pipe arrangements are modelled. Eventually, the effectiveness of the designed solutions is verified with detailed numerical simulation. The design which includes the air-intake main structure made of CMC material and integrating Nickel - Potassium heat pipe results to be the most promising solution to withstand the high thermal loads experienced by STRATOFLY MR3 throughout its Mach 8 long-haul route

Aero-thermal design of STRATOFLY MR3 hypersonic vehicle

Civil hypersonic flights are one of the key technological challenges of next generation. The EC-funded STRATOFLY (Stratospheric Flying Opportunities for High-Speed Propulsion Concepts) project has the objective of assessing the potential of this type of high-speed transport vehicle to reach TRL6 by 2035, with respect to key technological, societal and economical aspects, namely thermal and structural integrity, low-emissions combined propulsion cycles, subsystems design and integration including smart energy management, environmental aspects impacting climate change, noise emissions and social acceptance, and economic viability accounting for safety and human factors. This paper presents the aerothermal design of the new STRATOFLY MR3 hypersonic vehicle

Design Optimization of Interfacing Attachments for the Deployable Wing of an Unmanned Re-Entry Vehicle

Re-entry winged body vehicles have several advantages w.r.t capsules, such as maneuverability and controlled landing opportunity. On the other hand, they show an increment in design level complexity, especially from an aerodynamic, aero-thermodynamic, and structural point of view, and in the difficulties of housing in operative existing launchers. In this framework, the idea of designing unmanned vehicles equipped with deployable wings for suborbital flight was born. This work details a preliminary study for identifying the best configuration for the hinge system aimed at the in-orbit deployment of an unmanned re-entry vehicle’s wings. In particular, the adopted optimization methodology is described. The adopted approach uses a genetic algorithm available in commercial software in conjunction with fully parametric models created in FEM environments and, in particular, it can optimize the hinge position considering both the deployed and folded configuration. The results identify the best hinge configuration that minimizes interface loads, thus, realizing a lighter and more efficient deployment system. Indeed, for such a category of vehicle, it is mandatory to reduce the structural mass, as much as possible in order to increase the payload and reduce service costs

Evaluation expérimentale et numérique de la variabilité intra du comportement vibro-acoustique de structures automobiles, du niveau élémentaire à la prestation

COMPIEGNE-BU (601592101) / SudocSudocFranceF

Thermo-structural design of a Ceramic Matrix Composite wing leading edge for a re-entry vehicle

The design of the wing leading edge of re-entry vehicles is a very challenging task since severe aerothermal loads are encountered during the re-entry trajectory. Hence, advanced materials and structural concepts need to be adopted to withstand the elevated thermal gradients and stresses. Furthermore, particular attention must be paid to the design of hot areas and connections between hot and cold areas of the structure, where the presence of major thermal gradients associated to significant thermal expansion coefficients variations, can lead to damage onset and failure. In order to face this issues, Ceramic Matrix Composites are generally employed as passive hot structures due of their capability to operate at elevated temperatures retaining acceptable mechanical properties. In the present work a novel thermo-structural concept of an hypersonic wing leading edge is introduced and verified by means of an advanced finite element thermo-structural model

Thermal Management of the Hexafly-Int Hypersonic Glider

status: publishe

THERMO-STRUCTURAL DESIGN OF THE HEXAFLY-INT EXPERIMENTAL FLIGHT TEST VEHICLE (EFTV)

status: publishe