A flight test demo to acquire data in specific flight conditions and representative of airlines operations will be carried out with an Airbus A320 reusing HLFC test fin developed in a former EU project. Demo 2 will include the design, build and test of a large-scale ground based demonstrator of HLFC technology applied on a wing at TRL4. The work package of the project will include two major ground-based demonstrators and one flight-test demonstration, which are complemented by research and windtunnel tests:ĭemo 1 will focus on the development of HLFC horizontal tailplane and large-scale ground based testing to achieve a fully functional HLFC on a leading edge segment at TRL6. The complexity, weight, industrial viability, and operability of the required systems are key to materialise the aerodynamic benefits“ says Hue. Suction will be applied at the leading edge of airframe components such as on the wing, tails or nacelles. “Drag reduction by using laminar flow technology offers a potential double-digit decrease of specific fuel burn for large and faster long range aircraft.
So what we’re trying to achieve with our HLFC system is to make sure we maintain the laminarity on the airfoil of the wing and/or the vertical/ horizontal tail plane for as long as possible, so that the air is flowing in parallel layers“. What we’re aiming for is to have the air flow around the airfoil (it can be a wing and/or a vertical/horizontal tailplane) more like the stable, lower part of the flame. There we want to reduce the turbulent part of the flow that is generating drag, which means more fuel consumption. If we transpose this comparison onto an aircraft the air around the wing behaves like the flame. “Think of laminarity as that lower, more stable part of the flame and contrast that with the top part of the flame which is “turbulent“, moving everywhere. The bottom part of the flame is quite stable, but the top of the flame moves erratically“ explains Xavier Hue - Clean Sky 2 Technical Leader at Airbus. Hybrid Laminar Flow Control, the subject of the HLFC Demonstrator project within Clean Sky 2’s Large Passenger Aircraft (LPA) Innovative Aircraft Demonstration Platforms (IADP), is a means to ensure that the air flows around certain parts of the aircraft in parallel layers using a hybrid structure which can be mounted on the leading edge of the tail and of the wing, and by so doing, significant fuel savings and environmental benefits are possible. Laminar flow is the Holy Grail for aerodynamicists, and in fluid dynamics laminar flow occurs when a fluid flows in parallel layers, with no disruption between the layers.