Final Report Summary - HEXAFLY-INT (High-Speed Experimental Fly Vehicles - International) An executive SummaryCivil high-speed passenger transport only makes sense when deployed for long-haul intercontinental flights.Consequently, the related development and deployment of such a high-speed vehicle will most likely demandan international approach. The internationally funded HEXAFLY-INT project is a first step in the direction ofcivil high-speed transportation along with an international development where flight-testing is the focal point.The global aim is to flight test an experimental waverider-based vehicle concept above Mach 7 to verify itspotential for a high cruise efficiency during a free-flight. In parallel, the concept will also be flight tested to provethe waverider concept is also able to take-off, to accelerate to subsonic speed and to land in an efficient androbust way.The feasibility for a 3m long vehicle was demonstrated during the European precursor project HEXAFLY. Itsrealization is now being enabled on an international scale preparing the grounds for global cooperation in caseof a future deployment of a high-speed cruiser. These flight opportunities will increase drastically theTechnology Readiness Level of developments realized in previous high-speed EC projects such as ATLLAS I, II and LAPCAT I, II. Project Context and ObjectivesThe overall objective of HEXAFLY is to create a generic high-speed platform enabling in-flight testing of severalbreakthrough technologies. To mature this idea, a scientific mission profile was worked out based upon apreliminary design of a high-speed flight test vehicle along with the identification of the most promising flightplatform, e.g. sounding rocket. This combination would then offer the possibility to test out varioustechnologies, grouped around the six major axes of HEXAFLY:1. High-Speed Vehicle Concepts to assess the overall vehicle performance in terms of cruise-efficiency,range potential, aero-propulsive balance, aero-thermal-structural integration, etc...2. High-Speed Aerodynamics to assess aerodynamic vehicle shapes with high L/D, aerodynamicmanoeuvrability, stability, etc…3. High-Speed Propulsion to evaluate the performances of high-speed propulsive devices such as intakes,air-breathing engines, nozzles including phenomena such as high-speed combustion, injection mixingprocesses, etc…4. High-Temperature Materials and Structures to flight-test under realistic conditions high temperaturelightweight materials, cooling concepts, reusability aspects…5. High-Speed Flight Control requiring real-time testing of Guidance Navigation Control in combination withtechnologies on Health Monitoring Systems/ Fault Detection and Isolation6. High-Speed Environmental Impact focusing on reduction techniques for sonic boom and sensitivities ofhigh-altitude emissions of H20, CO2, NOx on the stratosphere.Following this general HEXAFLY philosophy, a first project on international level was proposed, HEXAFLYINTernational, with the auspices of the European Community (EC) together with 11 partners from Europe(ESA, AIRBUS, CIRA, DLR, ONERA, TET, TSD, GDL, Marotta, Univ. of Stuttgart, VKI ), 4 from the RussianFederation (TsAGI, CIAM, LII and MIPT) and 3 from Australia (Univ. Sydney, UNSW, USQ). The overall aimis to design, manufacture and flight test a high-speed vehicle, based on the configuration developed in previousEC co-funded projects ATLLAS I, II [1][2][3], LAPCAT I, II [4][5], and HEXAFLY [6][7]. Under HEXAFLYINT, both a glider and a hydrogen-propelled variant of the high-speed vehicle are being considered, the formerbeing developed by EC partners with international partners, the latter being developed only by the Russianpartners. The flight experiment carried out by the Europeans, Russians and Australians, is focused on- Elaborating a self-controlled glider demonstrating a high aerodynamic efficiency in combination with ahigh internal volume- a positive aerodynamic balance at a cruise Mach number of 7 to 8 in a controlled way- making optimal use of advanced high-temperature materials and/or structures- the aerodynamic gliding performance from Mach 8 down to Mach 2- including several breakthrough technologies on-board [10],- validating methods and technologies deployed in hypersonic vehicles design [7][10][11][12][14]. HEXAFLY-INT Del. No. D1.2.9 Final Report - Page 8 of 50Two distinctly different flight tests are considered. One at high-speed checking the cruise capability of apotential civil passenger hydrogen fuelled high-speed vehicle, another at low-speed to check its handlingqualities during take-off and landing.The Experimental Flight Test Vehicle (EFTV), for testing the cruise performance as a non-propelled glider athigh-speed will be launched by a sounding rocket (the Brazilian VS50 launcher based upon an 12-ton solidrocket motor) in a suborbital trajectory having an apogee at about 100 km ().After the release from the launcher, the EFTV will perform the first part of the descent docked to theExperimental Service Module (ESM), which controls the vehicle attitude. As soon as the EFTV features fullaerodynamic control authority, it undocks from the ESM and pulls out from its descent to perform a hypersoniccruise at approximately Mach 7. In this experimental phase, the EFTV aims to demonstrate as a glider a highaerodynamic efficiency (L/D≥4), a positive aerodynamic balance at controlled cruise Mach numbers (7÷8) andan optimal use of advanced high-temperature materials and structures. The overall mission requirements arelisted in Table 1.The vehicle design, manufacturing, assembly and verification are the main drivers and challenges in thisproject in combination with a sounding rocket tuned for the mission. Both the glider and the propelled optionsof the HEXAFLY-INT high-speed vehicle are characterized from the aerodynamic and aerothermodynamicpoints of view.Besides the high-speed flight experiment, an additional low-speed flight experiment will be performed tocrosscheck the viability of the vehicle concept for later deployment as passengers’ aircraft. It entails a flightexperiment in the Danger Area 451 (Univ. of Sydney) to verify the take-off, cruising at a low subsonic speedand landing potential for the waverider-based vehicle and its related control authority.The program was kicked off in April 2014 and will pass the CDR by end of 2018. The paper describes thestatus of the vehicle design along with the elements related to the flight preparation.In parallel to the overall technical work to realize the different flights and experiments, a framework has beenset up to ease the exchange of students of the involved universities among the different partners. This givesthem a unique expertise of contributing to the different pieces of one of these flight experiments. Related documents final1-d1-2-9-v1-0-hxi-final-report-public-chapters.pdf
