Roberto Scigliano

Design Analysis of the High-Speed Experimental Flight Test Vehicle HEXAFLY-International

Achieving airbreathing hypersonic flight is an ongoing challenge with the potential to cut air travel time and provide cheaper access to space. Waveriders are potential candidates for achieving hypersonic cruise or acceleration flight within the atmosphere. Current research tends to focus on key issues like thermal loading, aero-elasticity and aerothermodynamics at hypersonic speeds. Design problems in each of these areas must be solved if a hypersonic waverider design is to be viable. In this frame the HEXAFLY-INT project aims at the test in free-flight conditions of an innovative gliding vehicle with several breakthrough technologies on-board to be launched along a suborbital trajectory. Its preliminary conceptual design has been carried out by means of a number of numerical tools suitable to design vehicles flying in hypersonic conditions. The main results of the design analysis carried out during the preliminary phase of the study, such as vehicle aerodynamics and aerothermodynamics, re-entry trajectories, structures and mechanisms, and on the overall system, as well, are presented in this work.

Aerothermal Design of the Hexafly-int Glider

Over the last years, innovative concepts of civil high-speed transportation vehicles were proposed. These vehicles have a strong potential to increase the cruise range efficiency at high Mach numbers, thanks to efficient propulsion units combined with high-lifting vehicle concepts. In this framework the Hexafly-INT project has the scope to test in free-flight conditions an innovative gliding vehicle with several breakthrough technologies on-board. This work describes the aero-thermal design processes of the Hexafly-INT Experimental Flight Test Vehicle, namely EFTV.

Thermo-structural design of the Hexafly-INT Experimental Flight Test Vehicle (EFTV) and Experimental Service Module (ESM)

Over the last years, innovative concepts of civil high-speed transportation vehicles were proposed. These vehicles have a strong potential to increase the cruise range efficiency at high Mach numbers, thanks to efficient propulsion units combined with high-lifting vehicle concepts. Nonetheless, performing a flight test will be the only and ultimate proof to demonstrate the technical feasibility of these new promising concepts and would result into a major breakthrough in high-speed flight. In this framework the Hexafly-INT project has the scope to test in free-flight conditions an innovative gliding vehicle with several breakthrough technologies on-board. This work describes both the thermo-structural design process of the Hexafly-INT Experimental Flight Test Vehicle, namely EFTV, and of the Experimental Service Module, namely ESM. The paper will present results of a Finite Element thermal analysis, performed in the most critical phases along the flight trajectory in order to drive a preliminary material selection.

Ice release phenomena modelled by Finite Element models

The main purpose of this paper is to present an ice release fracture model taking into account the cohesive phenomena. Developed on the basis of the standard finite element method implemented in ANSYS software, the test-case consists in an iced cantilever beam (structurally representative of an engine rotating component) excited by applying a vibrating impulse able to generate ice fracture. Interfacial shear stress on ice/bar interface has been evaluated and results have been validated with literature data.

Thermo-Structural Design of the HEXAFLY-INT Experimental Flight Test Vehicle (EFTV)

The Hexafly-INT project intends to test in free-flight conditions an innovative gliding vehicle with several breakthrough technologies on-board. This approach will create the basis to gradually increase the readiness level of a consistent number of technologies suitable for high-speed flying systems.This paper presents a Finite Element thermal analysis of the Experimental Flight Test Vehicle, combining information coming from the flight trajectory, the structural layout, the vehicle aerothermodynamics and the thermal behavior of the preliminarily selected materials in high temperature conditions. Numerical results show the thermal performances of the selected high temperature resistant materials in moderate enthalpy flow conditions and provide fundamental information on the thermal loads to be considered for structural analyses.Copyright