Rain Erosion Modeling for Hypersonic Thermal Protection System (TPS) and Structures

Within the hypersonic missile community, it is generally known that Mentis Sciences, Inc. (MSI) is developing a candidate Quartz/Polysiloxane radome solution for the Patriot Advanced Capability (PAC3) system. This solution is presently in the process of being evaluated for the relevant hypersonic rain erosion environs and full-scale thermal/structural loading. At this time, it has exceeded all mechanical, thermal, and electrical and cost requirements, however it too has experienced significant material loss during recent full-scale sled tests through a rain field. As a result of these tests, and the modeling research conducted during the Phase I effort, MSI investigated alternative 3D reinforced fiber architectures to address the issue of material loss and or wear. Phase I results indicate that high shear stresses due to droplet impact precipitated delamination of the 2D laminates, which ultimately lead to tensile failure of the outer fiber layer. Repeated impacts coupled with aerodynamic shear caused dramatic material loss. The Phase I effort systematically quantified the erosion event, and ultimately led to the investigation of 3D fiber architectures. This effort will be supported by The University of Delaware's Center for Composite Materials (CCM) with extensive material modeling to determine the loading interaction with the material and different 2D and 3D fiber architectures as well as subscale wear testing to screen and rank candidate materials.