A Review of Industrial Aeroelasticity Practices at Dassault Aviation for Military Aircraft and Business Jets


E. Garrigues (Dassault Aviation)

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Aircraft structure design is a complex industrial process that requires multidisciplinary analyzes and considerations in fields as diverse as aerodynamics, structure, materials and systems, as well as the right compromise between the constraints imposed by these different fields, in order to meet the overall performances required for aircraft. In the field of business jets and military aircraft, given the research into ever more efficient aerodynamic formulas, the constant desire to design "as light as possible", and the increase in fuselage sizes, aircraft flexibility has increased considerably over the last few decades. This has required the consideration of increasingly complex aeroelastic coupling phenomena that are present in the flight envelope from the very first phases in aircraft development. The challenge goes far beyond the domain of aerostructural performance alone, since aeroelasticity can also have a significant impact on related domains, such as aircraft performances, handling qualities, or system design. It has merely reinforced the potentially major impacts of aeroelasticity on the risks, costs and deadlines for new aircraft programs: aeroelasticity is now seen as one of the main disciplines in design, and as one of the "critical" processes in the aircraft development logic.
This highly-challenging context has been the source of major and constant modifications in the field of aeroelasticity since the 1990s at Dassault Aviation. Today, this trend continues, and aeroelasticity will have to tackle a series of entirely new challenges and needs, and continue to reinvent itself at the same pace if it is to avoid hampering innovation and future technological breakthroughs. In this perspective, this article gives an overview of the current best industrial ractices in terms of aeroelasticity in the military aircraft and business jet domains at Dassault Aviation. The main aspects of this challenging and exciting field are covered: the numerical methods and tools, the experimental validation process, the aircraft program expectations and aspects relating to human organization. It discusses the principles and guidelines rather than details about the basic equations and methods. The last part presents the future industrial challenges in the field of aeroelasticity for Dassault Aviation.




Video 1: typical flutter displacement mechanism computed on the RAFALE in air-to-ground configuration, far away from the flight-domain envelope


Video 2: typical wind-tunnel flutter test on a MIRAGE F1 with a dynamically-similar flexible mock-up



Video 3: wind-tunnel flutter test on a military wing in complex configuration near the flutter point, before and after the flutter instability is detected and the automatic wind-tunnel security system activated



Video 4: typical CFD DES computation on a Falcon with interaction between wing and horizontal tail plane at a high angle of attack