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. 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. Equally importantly, our mesh is of regular orientation and is not stochastic in any way. 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. The porosity of the mesh can be manipulated by the designer and tailored (within the same faceplate) to the local flowfield. The CAD file for such meshes is very small (~10kB), which results in very small STL and slice files. 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 0.012". With this new technology we have developed, holes as small as 0.003" 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.
Artemis program Lunar Lander main propulsion
Mars ascent vehicle main propulsion
Commercial launch main propulsion
Valve and fluid control devces
Heat exchanger components