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ptc-39481071-Visitor
1-Visitor
February 17, 2012
Solved

ODE Temperature profile solution

  • February 17, 2012
  • 1 reply
  • 2301 views

I've having a bit of a problem using the rkfixed function (have tried Rkadapt and Odesolve and results in the same problem).

The ODE describes the temperature profile in a length of pipe cooling from the feed temperature to an ambient temperature. However, the rkfixed solution results in an unexpected exponential growth curve.

Luckily the function can actually be integrated by hand, plotting this gives the expected exponential decay.

Graph in the attached file shows the rkfixed result as T and the analytical solution as Tb.

Thanks

Cameron

Best answer by Fred_Kohlhepp

You've got your subtraction backwards.

1 reply

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Fred_Kohlhepp23-Emerald IAnswer
23-Emerald I
February 17, 2012

You've got your subtraction backwards.

P
ptc-39481071-VisitorAuthor
1-Visitor
February 17, 2012

Now that was kinda obvious. Although it does now raise more questions and doubt about the accuracy of the equation's source (published article).

Thanks

Cameron

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