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Minimize problem

SOLVED
DJF
Alexandrite

Minimize problem

Attached is a little problem in 4.0 that has me stumped - not sure how to set it up to solve.  

The problem is for a pump - which we know performance of.  I need to find the speed to deliver the required flow and pressure must exceed the requirement (it can be higher) and the speed should be such that the consumer power is lowest while meeting the flow & pressure needs.  Since efficiency/flow/head curves vary it's possible that the lowest power speed delivers more pressure than necessary, but does so efficiently.

 

Everything works up to the solve block, and despite many attempts I can't figure out how to formulate it.

Thanks,

1 ACCEPTED SOLUTION

Accepted Solutions

Re: Minimize problem

Are you looking for something like this:

B2.png

3 REPLIES 3

Re: Minimize problem

You define DeltaP.act as a function of N2 but you define it as being constant 100 psi.

DeltaP.goal is defines as 500 psi.

So you demand Prime to find a solution with the constraint 100 psi > 500 psi ???

B.png

Re: Minimize problem

Are you looking for something like this:

B2.png

Re: Minimize problem

Yes, thank you.  It was just a question of setting it up right.  In between what to have as a guess, definition and constraint I always got errors or "No solution".  It always looks simple once you see the solution.