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1-Visitor
November 17, 2011
Question

Solve Block Optimisation

  • November 17, 2011
  • 1 reply
  • 2327 views

Hi All,

I'd like some assistance with some work I'm doing in Mathcad, specifically finding the maximum via a solve block. The background of this is that we're looking and skeletal impingement and we're trying to use Mathcad to find the optimal impingement.

Attached is the worksheet with all the relevant equations and values, these equations are not the ones I'm working with (they're REALLY large) so I've just taken enough to represent the problem I'm working with. When you open the files, what you'll see is:

  • CONSTANTS - fairly self-explanatory, these won't change
  • INPUTS - these are the variables we'll be altering to find the optimal result
  • EQUATIONS - the defined equations; the first two are calculated, and then fed into the second pair
  • CONSTRAINS - the only constraints that we have

So what I'd like to do, is to be able to set up a solve block to find the highest FL and EXT, by varying the alpha and beta input, without breaking the constraints. All help will be greatly appreciated, as I really can't get this to work.

Regards,

Jason

1 reply

19-Tanzanite
November 17, 2011

Firstly, you need to make D, E, FL and EXT functions of alpha and beta. You also need to create them as functions that guard against inadmissable values (eg at present D can be negative for some combinations of alpha and beta, so you get complex numbers when you take its square root; also, the argument to acos in the definition of FL can be well outside +/- 1). Then look up the maximize function in Help.

Alan

JasonLin1-VisitorAuthor
1-Visitor
November 18, 2011

Thanks Alan,

I'll give that a shot. Could explain how I might do the "inadmissible values" part of the worksheet?

Jason

19-Tanzanite
November 18, 2011

See attached.

Alan