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The other item to consider is impingement distance, or how far below the face plate the elements collide. Generally, smaller impingement distances correlate to increased performance, but that also means that combustion happens closer to the faceplate, which increases risk of faceplate melting. Impingement distance is also constrained by the geometry of the injector. An impingement distance that is 5 times the length of the average diameter of the orifices is recommended by the literature, and fortunately we were able to come close to this factor with an impingement distance of INSERT VALUE.
The other length that we need to consider is the thickness of the injector faceplate. The length of an orifice generally should range between 3-10 times its diameter; for this design we chose 5 for the oxidizer orifices and 4 for the fuel orifices (the only reason why they are different is due to spacing constraints. Using simple trig, this gives us a faceplate thickness of INSERT VALUE inches for the oxidizer, and INSERT VALUE inches for the fuel.
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