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Symposia
MULTI-MODAL MORPHING WING FLAPS FOR NEXT GENERATION
GREEN REGIONAL AIRCRAFT: THE CLEANSKY CHALLENGE
Rosario Pecora
Asst. Professor (Aircraft Structures)
University of Naples “Federico II” (Italy)
Abstract
Regional aviation is an innovation driven sector of paramount importance
for the European Union economy. Large resources and efforts are
currently spent through the CleanSky program for the development of an
efficient air transport system characterized by a lower environmental
impact and unequalled capabilities of ensuring safe and seamless mobility
while complying with very demanding technological requirements. The
Green Regional Aircraft (GRA) panel, active from 2006, aims to mature,
validate and demonstrate green aeronautical technologies best fitting the
regional aircraft that will fly from 2020 onwards with reference to specific
and challenging domains: from advanced low-weight and high
performance structures up to all-electric systems and bleed-less engine
architectures, from low noise/high efficiency aerodynamic up to
environmentally optimized missions and trajectories management. The
development of such technologies addresses two different aircraft
concepts, identified by two seat classes, 90-pax with Turboprop (TP)
engine and 130-pax, in combination with advanced propulsion solutions,
namely, the Geared Turbofan (GTF), the Advanced Turbofan (ATF) and the
Open Rotor (OR) configuration.
Within the framework of the Clean Sky program, and along nearly 10 years
of research, the design and technological demonstration of a novel wing
flap architecture was addressed. Research activities aimed at
demonstrating the industrial feasibility of a morphing architecture enabling using generalized coordinates that have minimal dimension. Such
flap camber variation in compliance with the demanding safety
requirements applicable to the next generation GRA in both open rotor
and turboprop configurations. The driving motivation was found in the
opportunity to replace a conventional double slotted flap with a single
slotted morphing flap assuring improved high lift performances -in terms of
maximum attainable lift coefficient and stall angle- while lowering emitted
noise, fuel-burnt and deployment system complexity. Additional
functionalities for load control and alleviation were then considered and
enabled by a smart architecture allowing for an independent shape-
control of the flap tip region during cruise.
The entire process moving from concept definition up to the experimental
qualification of true scale prototypes, characterized by global and
multi-zone differential morphing capabilities, is here described with
specific emphasis on the adopted design philosophy and implemented
technological solutions. Paths to improvements are finally outlined in
perspective of a low-term item certification and series production
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Biography
Masters degree in Aeronautical Engineering and Ph.D. in Transport
Engineering awarded by the University of Naples “Federico II” on 2002
and 2005. Assistant Professor of Aircraft Structures Stability and Lecturer
of Advanced Aircraft Structures at the same University since 2011. He has
worked for many aircraft manufacturing companies (including but to limited
to ATR, ALENIA AERMACCHI, BOMBARDIER, PIAGGIO AEROINDUSTRIES)
and research centers as technical advisor for loads, aeroelasticity, aircraft
structures design and certification (EASA CS-23,-25 standards). His
research activity is mainly focused on aero-servo-elasticity of
unconventional structural systems, structures dynamics and smart
structures while covering leading roles in major European and extra-
European projects (CAPECON, Clean Sky GRA, SARISTU, CRIAQ-
MDO505, Cleans Sky 2). He is author of several scientific papers and
designed inventor of European and US patents on SMA-based
architectures for morphing wing trailing edge.
DYNAMICS AND CONTROL OF TENSEGRITY SYSTEMS WITH RIGID
BARS AND MASSIVE TENSION MEMBERS
Robert E Skelton
TEES Distinguished Research Professor
Texas A&M University
Dept. of Aerospace Engineering
Dept. of Ocean Engineering
Abstract
The history of Multibody Dynamics includes a variety of methods of
characterizing the motion of connected bodies, both rigid and elastic,
equations, expressed in vector form, are usually very complex, with
trigonometric functions to be evaluated at every integration step, and
mass matrices that are functions of the generalized coordinates, requiring
inverting every integration step. This paper shows a characterization of
multi-body dynamics, with constant mass matrices and no transcendental
functions. The trick is to expand the dimension of the model to yield a
non-minimal model, but with very simply mathematical structure in the
equations, yielding very efficient computation. The new formulation
appears in a Matrix Second-Order (MSO) differential equation. The MSO
gives the exact nonlinear rotational motion of the rigid bodies within the
system, and exact equations of the translation of their mass centers. The
MSO opens up new challenges for control theory, so as not to require
minimal models (controllable/observable) before control design. The MSO
model allows flexible membranes to be built into the tensegrity network.
This opens the path for more efficient models of structures with covered
surfaces like airplane wings, and swimming structures, and soft robots