Flow simulation by a throttle valve

So I have my throttle model:


and I want to achieve something similar to this:


My question is related only to those flow lines. I’m not interested in cutting throttle itself.

I was trying making a collision tube with emitter at the beggining of it. I’ve tried fluid simulation, and newtonian. But I wasn’t even near that.

I don’t need any hyper realistic simulation but only achieve similar effect, and see how my lines will behave with different valve position.