This value must be a function

[JR_9175191]

Having an issue with the solve block, most likely because of my little experience with Mathcad.

I do have a function in the constraints, but don't know how to solve the issue.

Any recommendations will be greatly appreciated.

[terryhendicott · Accepted solution]

Hi,

One problem that will be encountered is a matrix mismatch. in the last equation.

Poor Prime will be confused.

Cheers

Terry

[JR_9175191]

I see that now, Et utilizes different turbine temperatures for different curves, I'm assuming I'll have to constrain it to one curve at a time, as that is what the compressor has.

[JR_9175191]

Fixed the matrix mismatch but, I'm still having the same issue with the function. Attached is the corrected version of the matrix.

[Werner_E]

The error stems from the condition P3=P3(ma,...)

The left hand side uses P3 as a scalar variable (with guess value 70), but on the right hand side P3 is used as an (undefined) function with four arguments. That can't work.

You will run into further errors, though.

For example: In your second and third conditions the left hand side (Ec) is a 3x1 vector, but the right hand side is just a single scalar. That never can be equal.

EDIT: I see that in the meantime you marked the thread as being solved. So you already found all problems and fixed them?

[JR_9175191]

I fixed the matrix issues and I saw that I hadn't defined the function so I'm in the process of doing that, hopefully it will solve my issues. Marked as solve as to not leave it open and forget to mark it as solved later on, if not i'll post again.

Thank you both for your help.

[JR_9175191]

I just saw what you meant with the second and third arguments, I think I might be better off making a separate document for this solve block and fixing out the kinks.