Three-dimensional structural topology optimization of aerial vehicles under aerodynamic loads

•Density distribution and optimality criteria based structural topology optimizations.•Ability to solve large-scale 3D structural topology optimization problems.•Accurate transfer of loads from a CFD to a structural topology optimization code.•Parallelized 3D CFD and structural topology optimization codes.•Post-processing features tailored for easy recognition of optimum topologies.

A previously developed density distribution-based structural topology optimization algorithm coupled with a Computational Fluid Dynamics (CFD) solver for aerodynamic force predictions is extended to solve large-scale problems to reveal inner structural details of a wing wholly rather than some specific regions. Resorting to an iterative conjugate gradient algorithm for the solution of the structural equilibrium equations needed at each step of the topology optimizations allowed the solution of larger size problems, which could not be handled previously with a direct equation solver. Both the topology optimization and CFD codes are parallelized to obtain faster solutions. Because of the complexity of the computed aerodynamic loads, a case study involving optimization of the inner structure of the wing of an unmanned aerial vehicle (UAV) led to topologies, which could not be obtained by intuition alone. Post-processing features specifically tailored for visualizing computed topologies proved to be good design tools in the hands of designers for identifying complex structural components.