The Aerothermal, and Structural Design of the Common Front End Flight Vehicle

The Common Front End is a high-speed flight testbed concept study being undertaken in a collaboration between Lockheed Martin Australia and The University of New South Wales, Canberra. This paper introduces the general mechanical arrangement of the Flight Experiment 1 (FE1) prototype vehicle. The workflow implemented to analyse and verify the mechanical integrity of the vehicle’s hot structure is described and the performance characteristics of aluminium, stainless steel, titanium, and nickel alloys are discussed. The materials are assessed with reference to a critical flight-condition consisting of Mach number, altitude and angle of attack, representative of the aerothermal extremes that the vehicle must survive in a test flight. Initial studies found there is no significant benefit from increasing the wall thickness beyond 4mm for the chosen materials and flight condition. This study determined that hot structure manufactured from Ti-6Al-4V with a 4mm wall thickness is suitable for further vehicle development. A further analysis specific to the Flight Experiment 1 (FE1) prototype geometry and updated flight trajectory demonstrates a process to carry out the structural simulation with limited aerothermal simulation effort. The results of the additively manufactured Ti-6Al-4V prototype using electron-beam melting (EBM) technology are discussed. Proof-of-concept features were manufactured, tested, and iterated, and then integrated into the prototype modules. Machined assembly features at the module interfaces were necessary to achieve the required tolerance fit.