Hello. I am a physician (medical doctor) with hardly a clue about fluid dynamics. A very long time ago I saw something about using fluid like an electrical circuit which could amplify the flow, making it outflow faster than inflow. This done without external energy, using only interconnecting channels. Does anyone have an idea what I am talking about and where can I find some basic references on the subject. Thanks.

I think you are talking about a nozzle flow. In nozzle, which is like a symmetric horn, if the incoming flow is slower then out going flow is faster. Same thing can also be achied if you put a oifice (O-ring) inside a pipe. Then the flow after the ring is faster than before the ring.

You can read any book by John D. Anderson, in my opinion he is a GREATE author! bye have a nice day

(1). The best place to start your search is the car automatic transmission expert. ( automatic transmission shop) (2). In the automatic transmission, there are complex circuits of small passage for transmission fluid to control the shifting of the transmission. Sometimes, two small side jet ports are used to control the movement of the large main jet in the center by changing the pressure difference in the side jet ports. It is call " fluidic devices" or something like that. It belongs to "hydraulic control" field, I think.