Eductor design equations

What part of your homework are thinking of doing yourself?

I would suggest that you make

-1. a research on the methods to design the device.

-2 you think it over and try to understand

-3 make the 1st attempt to design it and

4- if you are not convinced that what you did is correct THEN you ask CR4 for a comment or an explanation.

It is better for your own evolution to the profession to try first to solve the problem on your own and after you came to a result, being it partial, ask for help.

Eductor? Do you mean, 'Ejector'?

You want to use water as motive fluid to suck air, kind of vacuum pump, right?

You want the size of nozzle, venture ect. As suggested by Bware, that should be your homework, applying the fluid dynamic equations. Nick name has suggested the right approach for the project.

I can only suggest some fine-tuning steps:

The essence of such ejector is the 'velocity' of the motive fluid at the jet. This velocity is governed by the equation Q = A * V, where Q is the quantity of flow, A is the area of cross section and V is the required Velocity.

It is you to decide the Q, the V and A. How do we know what is your Q?

Having calculated the V and other functional areas and lengths, you may keep various sized jets, screwed to the nozzles. There by try the best one that give maximum velocity to your flow. You may keep the lengths also adjustable, by screwing in or out to obtain the optimum distance of the jet to throat.

Keep trying, good luck.