Wing Flexibility and Design

 

Evolutionary design and mechanical performance

of flexible wings


The instantaneous shape of flapping wings can have a profound influence on fluid dynamic force production and efficiency.  Insect wings bend and twist dramatically during flight, yet the effect of these dynamic, three-dimensional shape changes on unsteady aerodynamic force production and flight performance remains unresolved.  Because insect wings contain no muscles past their base, wing bending cannot be actively controlled.  Instead, dynamic shape changes are primarily determined by the evolutionary design - venation pattern, planform shape, and material properties – of the wing itself.


To investigate the relationship between wing structure and mechanical performance, we have performed a comparative analysis of wing venation and flexibility in a broad range of insects (Combes and Daniel, 2003a), and developed measurement techniques and computational models to investigate spatial variation in wing stiffness (Combes and Daniel, 2003b).  We have also used an analytical fluid dynamics model to examine how wing flexibility and planform shape affect force production (Combes and Daniel, 2001), and performed experimental and theoretical studies of  the relative importance of inertial versus aerodynamic forces in wing bending (Combes and Daniel, 2003c; Daniel and Combes, 2002).


We are continuing to study the role of wing flexibility in insect flight performance with a new project examining the role of resilin joints in insect wing bending.  We are also exploring numerous aspects of wing morphology and flexibility to derive general principles that will aid in designing artificial insect wings in collaboration with Robert Wood (Harvard SEAS), as part of the RoboBees project (http://robobees.seas.harvard.edu/).