Dynamic response of a composite propeller blade subjected to shock and bubble pressure loading

The interaction between an underwater explosion and a composite propeller involves several physical phenomena that an accurate numerical simulation needs to capture. These include proper description of the initial explosion shock wave, of its propagation in the water, and of its interaction with the propeller blades and any other neighboring boundaries. In this work, a numerical procedure which links a compressible flow solver with an incompressible flow solver is applied to capture both shock and bubble phases efficiently and accurately. Both flow codes solve the fluid dynamics while intimately coupling the solution with a finite element structure code thus enabling simulation of full fluid-structure interaction. This numerical approach is applied to the simulation of the interaction between an underwater explosion and a multi-layered propeller blade made of a set of composite materials. Fiber orientation in the various layers is studied to understand which combinations of materials and fiber orientations give the strongest resistance in terms of both bending and twisting of the blade.