Solving ODEs in mathcad prime 2.0

[Asad]

I need help solving these ODEs. File is attached and the ODEs to solve are at the bottom of the worksheet.

Thanks! Help is greatly appreciated.

[Werner_E]

Prime can solve ODEs only numerically.

You have to use a solve block with odesolve and you have to provide initial conditions.

Furthermore you have to write d/dz P(z) and not just d/dz P(z).

Additionally you can't write v^2 (z) as this is interpreted as v^2 * (z). You have to write v(z)^2.

I spot functions v,x,z and rho, all dependent on z.

But what about the expression d/dz (c.p*T.f) ? Is there a fitfth function dependent on z (which one - c.p or T.f - neither is defined)  and you have only four equations??

Also it may be problematic that you have a function x but x is also used as a variable (x=0013)

[Asad]

x is a variable for molar fraction, it is not a function. And the variable x is itself dependant on z coordinate.

Equations are there for calculating cp(z) and Tf is to be found, it the temperature and tells the temperature along z axis.

Yes four equations, for v(z), x(z), Tf(z), and P(z).

The other variables such as h, cp, rho are also dependant on z coordinate but we have direct equations to calculate the values at any point z.

[Werner_E]

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@Asad wrote:

x is a variable for molar fraction, it is not a function. And the variable x is itself dependant on z coordinate.

And this means that x actually IS a function of z but you had used x as a single variable with the constant value 0.013

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The other variables such as h, cp, rho are also dependant on z coordinate but we have direct equations to calculate the values at any point z.

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And so you have to provide those functions! None of them are defined in your sheet as far as I can see!

And as already written you also have to provide initial conditions!