| Attempts to copy nature in order to obtain new technologies or improve the ex- istent ones go back thousands of years, from the Chinese attempting to make artificial silk to Leonardo da Vinci's designs of flying machines inspired on the flight of birds. In some cases this transfer of technology, also known as biomimetics, bionics or biomimicry, can be done almost directly. The necessary conditions are that the natural structures and the man-made ones serve the same purpose and operate under similar constraints. The first engineering design studied in this work is one of such cases: a biomimetic wing inspired by the flipper of humpback whale. This design is studied in detail, via computational fluid dynamics, showing that the characteristic protuberances on the leading edge of the flipper improve aerodynamic performance with respect to a similar but "conventional" wing. Because, in general, engineering designs have no parallel in nature (different objectives, different constraints, different materials) copying is not the solution. We propose then a new method for topology, shape and size optimization - BioTOM (Biologically inspired Topology Optimization Method). This method doesn't look at the nature's structures but uses the process of natural selection in order to obtain optimal designs for engineering applications. Furthermore the layout generation for the BioTOM mimics the cellular development from a single cell to a multicellular structure through cell division and growth. The BioTOM is applied to a couple of benchmarks problems in topology optimization showing its superiority with respect to other evolutionary methodologies. The BioTOM is then applied to two other topology optimization problems of great interest in engineering. The results demonstrate that BioTOM is a very useful and general methodology that can be used to optimize topologies and shapes in order to minimize weight, maximize aerodynamic performance, etc. |
