Design of Eductor

http://www.nciweb.net/eductors.htm

Google Bernoulli...

You will doubtless need some trial and error.

Can u please suggest me how ?

And indeed I am not having any concrete data as my Boundary condition to proceed with.

Take a pipe. Make a (smooth) restriction inside (e.g. turn a solid plug with a hole in the middle and push this into the pipe) drill a hole into the restriction through the side, push a small stub of pipe into this.

Let water flow through the main pipe. Attach a U tube manometer to the small stub of pipe and see if you have any suction.

It's called having a play to see what happens.

Chose you start point from any constaints which exist for your application .

Alternatively buy a cheap one..there are many very cheap ones designed for mixing cleaning products into water for floor scrubbing machines and such like. Take it to pieces...improve it/modify it to suit your application.

NOTE:- Hard water will fur up the jets of these things...