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ptc-46056121-Visitor
1-Visitor
May 30, 2012
Question

Solving This Equation

  • May 30, 2012
  • 2 replies
  • 2918 views

I am trying to formulate and equation/program in Mathcad that can determine the value of m, n, and C of the following equation:

Nu = C*(Re)^m(Pr)^n

all of the other values are given: Nu, Re, Pr

2 replies

A
AlanStevens19-Tanzanite
19-Tanzanite
May 30, 2012

Kevin Price wrote:

I am trying to formulate and equation/program in Mathcad that can determine the value of m, n, and C of the following equation:

Nu = C*(Re)^m(Pr)^n

all of the other values are given: Nu, Re, Pr

Presumably you have a set of values of Nu, Re and Pr to which you want to fit the heat transfer correlation. See attached for an approach using Given .. Minerr that might be of some help. Note that since you didn't supply any real data I've constructed totally arbitrary data.

Alan

P
ptc-46056121-VisitorAuthor
1-Visitor
May 30, 2012

Ok Thanks sorry here is my data I have to work with:

Pr = 3.033

Re = 0.397

Nu = 0.048

Trying to find : C, m, and n

A
AlanStevens19-Tanzanite
19-Tanzanite
May 30, 2012

With a single data set you can find an infinite number of different solutions for C, m and n. You need more data to achieve a meaningful result.

Alan

PS What fluid are you using and what's the system? The Prandtl number seems very high and the Reynolds number and Nusselt numbers seem very small (at least, that's the case for fluids and systems I've experienced).

T
Tezza20101-Visitor
1-Visitor
September 3, 2012

Hi Kevin,

Old post, but listed as unaswered. Who says can't be solved. Within limits and graphically can examine the problem. Simple in MathCad.

Here tis - possible solution? Simply muck about with "np" and ranges to examine to your hearts content.

Regards

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