Although these days it is considered a 'toy', a boomerang is a sophisticated device which poses a challenging design problem as it is subjected to six degrees of freedom and unsteady aerodynamic effects which, due to the rotation, vary from section to section along its length during flight. In addition, variations in the launch (due to the launching person’s strength, technique etc.) add significantly to the complexity of the design problem.
This presentation shows how the process integration and design optimization software modeFRONTIER was coupled to STAR-CCM+ to optimize the shape of a boomerang in order to minimize the launching energy required while still reaching a minimum acceptable range and a minimum returning distance.
The geometry was parameterized in CATIA using Bezier splines, and meshed and analyzed in STAR-CCM+. The coupling to STAR-CCM+ was accomplished via modeFRONTIER’s new direct integration with Optimate. This integration allows the geometry to be modified either in the STAR-CCM+ CAD Modeler or, as in this case, in a separate CAD tool.
In order to keep the number of CFD runs manageable, a fairly low number of configurations were run for each candidate design proposed by the optimization algorithms of modeFRONTIER. These results were then used to train response surfaces (or metamodels) which were subsequently used for the numerical integration of the equations of motion.
The result of the optimization was a boomerang configuration which required very low launch energy to reach the specified minimum range, as well as tuned throwing control parameters to optimize returning accuracy. The optimized geometry was created using a 3D printer and will be displayed at the conference.