  Insect wings can undergo significant deformation during flapping motion owing
to inertial, elastic and aerodynamic forces. Changes in shape then alter
aerodynamic forces, resulting in a fully coupled Fluid-Structure Interaction
(FSI) problem. Here, we present detailed three-dimensional FSI simulations of
deformable blowfly (Calliphora vomitoria) wings in flapping flight. A wing
model is proposed using a multi-parameter mass-spring approach, chosen for its
implementation simplicity and computational efficiency. We train the model to
reproduce static elasticity measurements by optimizing its parameters using a
genetic algorithm with covariance matrix adaptation (CMA-ES). Wing models
trained with experimental data are then coupled to a high-performance flow
solver run on massively parallel supercomputers. Different features of the
modeling approach and the intra-species variability of elastic properties are
discussed. We found that individuals with different wing stiffness exhibit
similar aerodynamic properties characterized by dimensionless forces and power
at the same Reynolds number. We further study the influence of wing flexibility
by comparing between the flexible wings and their rigid counterparts. Under
equal prescribed kinematic conditions for rigid and flexible wings, wing
flexibility improves lift-to-drag ratio as well as lift-to-power ratio and
reduces peak force observed during wing rotation.
