MathCAD ODE Problem

[DaleLabitzke-di]

I'm working on what I though to be an easy problem to predict temperature of a tank as a function of time. The tank contains water and some solid pellets, each containing solvent. The tank is heated with a steady source of energy. The solvent is boiled off. The solvent fraction of the liquid, pellets, and evolving vapor are all known and are each a function of temperature.

Odesolve seems to work but when I attempt to get an answer from the generated function or generate a graph, an error "This value must be a scalar" is reported.

It really has me confused. Obviously I don't use Odesolve often enough. Any help would be appreciated.

Best regards,

[AlanStevens · Accepted solution]

See attached.

Alan

[DaleLabitzke-di]

Ever so clever. Wish my brain worked like that.

Thanks so much!

[PhilipOakley]

Dale,

The first odesolve parameter (tau) should be the function name alone without the parameters. (a little detail hidden in the help file)

Then let Alan's solution speak for itself....

Philip

[AlanStevens]

Philip Oakley wrote:

Dale,

The first odesolve parameter (tau) should be the function name alone without the parameters. (a little detail hidden in the help file)

Philip

Note that this is only needed when solving a system of ODEs. For a single ODE it isn't used.

Alan