The HEXAFLY project aims to mature an experimental high-speed self-propelled vehicle in combination with several multi-disciplinary technologies. By this approach, the grounds for a future flight test will be prepared and potential technological risks identified in time. This potential will increase drastically the Technology Readiness Level (TRL) of developments realized in previous high-speed aeronautical projects on national and European level such as ATLLAS I & II and LAPCAT I & II.
The different technologies and methodologies which need experimental flight testing at high speed are grouped around the six major axes of HEXAFLY:
- High-Speed Vehicle Concepts
- High-Speed Aerodynamics
- High-Speed Propulsion
- High-Temperature Materials and Structures
- High-Speed Flight Control
- High-Speed Environmental Impact
To mature this experimental flight testing, a scientific mission profile will be defined followed by a proof-of-concept based upon:
- A preliminary design of a high-speed experimental flight vehicle covering the six major axes
- Selection and integration of available ground-tested technologies
- Identification of the most promising flight platform(s)
This allows to address the following items for a follow-up project:
- Identification of potential technological barriers
- Assessment of the overall ROM-costs
- The progress and potential of technology development at a higher TRL
The design of the experimental high-speed cruise vehicle design will be the main driver and challenge in this project with following scientific objectives:
- A positive aero-propulsive balance at a cruise Mach number of 8
- An integrated conceptual design demonstrating a combined propulsive and aerodynamic efficiency
- Making maximum use of earlier developed advanced high-temperature materials and/or structures
- An evaluation of the sonic boom impact by deploying dedicated ground measurement equipments
High-speed test aircraft
An EU team designed and tested an experimental supersonic test aircraft. The platform allows cheaper evaluation of candidate payloads and facilitates study of numerous aspects of high-speed flight.
High-speed aircraft have been around for decades, yet their use as effective passenger vehicles depends on performance competitive with conventional aircraft. Achieving the performance targets requires experimental testing, which is very expensive.
The EU-funded HEXAFLY (High-speed experimental fly vehicles) project aimed to create a new experimental high-speed vehicle. The proposal will be self-propelled and incorporate several testing technologies. Development will thus prepare the way for larger experimental flight testing platforms, also allowing the risks of candidate technologies to be assessed before deployment. The six-member consortium addressed a six-part research programme, including high-speed vehicle propulsion, aerodynamics, control and other engineering aspects, including the environmental impact of such vehicles. The undertaking ran between October 2012 and March 2014.
During the first reporting period, the project achieved a development plan for the vehicle via a two-fold process. First, the team assessed the suitability of proposed subsystems for flight test environments. Such steps consisted of: preliminary trajectory modelling, computational fluid dynamics modelling of external dynamics and engine performance, and thermal assessment of the combustion chamber. Next, the group laid out the various flight test options.
Work yielded definitions for three vehicle architectures. The stage also included a free-flight experiment using a large vehicle, of which the project developed two versions. Further definitions included: a vehicle mounted on the leading edge absent platform; and a captive carry trial using a small vehicle, to be launched from a sounding rocket.
HEXAFLY developments will help to realise platforms for testing of high-speed flight offering lower costs than currently possible. Such a result would advantageously position European industry.