I've used those hand soaps that have close to a 5:1 ratio of water to
soap in them and when you press down on the top, they produce a soap
foam. I'd like to make a nozzle that does this on a larger scale. I've
seen ones for pressure washers that aspirate the soap into the nozzle,
but I want one that works just like the hand soap one. I want to just
have to force the premixed diluted soap mixture into the nozzle and
have foam come out at a velocity proportional to the input pressure.

Does anyone know how something like that would be designed?

Thanks in advance for any info.