EDITED: Most of what I found seemed to be code to include fluid dynamics simulations into other software or code in, code out types of software needing other niche software to read and interpret the outputs. https://openfoam.org Seems super complex but may be the perfect solution. But the subject matter is too so... These may be what you are looking for. https://github.com/tumaer/JAXFLUIDS https://github.com/quinoacomputing/quinoa https://github.com/KyrilPalaveev/Axisymmetric-Method-of-Characteristics-Nozzle-Designer-with-GUI https://github.com/tomooda/HoneyGinger https://github.com/eric2003/OneFLOW

Would n't the cfm be determined by the bore stroke, cam rpm and valve size? The intake could be a mile long if you are injecting into the intake ports of the head.