Highly Compatible, Additively Manufactured LOX Injectors

AFA is pleased to present this proposal to continue development of our breakthrough capability in the additive manufacture (a.k.a. 3-D printing) of extremely fine meshes, which can be used as a direct replacement for Rigimesh.nbsp; Our meshing technology provides equivalent propellant flow and transpiration cooling behavior as Rigimesh, but eliminates the need for welding that faceplate in place, which results in a drastic reduction in both cost and lead time for a modern propellant injector.Importantly, our mesh is not based upon either a CAD representation of a faceplate that contains thousand or tens of thousand of individual orifices, which makes the STL and slice files (needed for actual printing) prohibitively large (~5 GB) and extremely low-quality.nbsp; Equally importantly, our mesh is of regular orientation and is not stochastic in any way.nbsp; We proved in Phase I that such meshes do not flow in a manner consistent with good injector compatibility or in a repeatable manner.Instead, our regular mesh is printed by direct, but simple (in hindsight) manipulation of the selective laser melting (SLM) process itself.nbsp; The porosity of the mesh can be manipulated by the designer and tailored (within the same faceplate) to the local flowfield.nbsp; The CAD file for such meshes is very small (~10kB), which results in very small STL and slice files.nbsp; It also means the resultant mesh prints very quickly compared to both alternative approaches.Critically, our mesh printing technology enabled a breakthrough in the printing of small orifices: AFA was among the best AM vendors in the printing of small holes using traditional CAD depictions, and the smallest holes were able to print prior to this Phase I was on the order of 0.012quot;.nbsp; With this new technology we have developed, holes as small as 0.003quot; were printed during Phase I and showed excellent repeatability and excellent flow behavior.In the end, AFA clearly demonstrated feasibility in printing a mesh faceplate.