Solving differential equation in Matcad Prime 2

[ptc-4501676]

Hi,

I am a newbie with mathcad.

I am trying to solve differential equations for water flood height calculation.

I followed an example written in previous Matcad and tried to modify it to fit with Mathcad Prime 2.

I don't have the original matcad code, only the print out.

Somehow I couldn't define the equation for dH0/dt and dH1/dt correctly in Mathcad Prime 2. Have tried to see the tutorial example but didn't suceed in define the differential equation.

Thanks for your help

Krisnandito

[ValeryOchkov · Accepted solution]

H must be a vector - H[0 and H[1.

0 and 1 are not a subscript - see the attach.

[ptc-4501676]

Thanks a lot Valery 🙂

[ValeryOchkov]

Krisnandito Hardjoko wrote:

Thanks a lot Valery 🙂

You welcome!

More correct solution (with units) in attach.

You can use the odesolve function too (see attach).

In this case you have the solutions as not sets of values but as functions.

[ptc-4501676]

Thanks again Valery. It is really helpful.

Kikis

[ValeryOchkov]

I am glad to help you!

Send please the final solution - with more remarks.

[ptc-4501676]

Here is the final solution. I added more remark, revised the differential equation and initial condition, and used ODEsolve to find the time when the MCR (H1) reach 4". Thanks to Valery.

[ValeryOchkov]

Krisnandito Hardjoko wrote:

Here is the final solution. I added,,, and used ODEsolve to find the time when the MCR (H1) reach 4".

Sorry, you can find "MCR (H1) reach 4" by using a root function - see the attach.

[ptc-4501676]

Wow this perferct Valery. Thanks ..

[ptc-4501676]

Valery, how did you make the marker callout in the graphic ver-5 have variable and unit separate by a line? I tried to input variable and then unit but it didn't work. Thanks

[ValeryOchkov]

[ptc-4501676]

thanks Valery. I understand now, we have to put division operator after variable and then put the unit.

[ValeryOchkov]

Krisnandito Hardjoko wrote:

thanks Valery. I understand now, we have to put division operator after variable and then put the unit.

...and then put the unit of the axes.

[ValeryOchkov]

I can forgive much to Mathcad Prime for the fact that it can work with units by the ODE solving.

[ptc-4501676]

I agree 🙂