questions on solving partial differential equation(s) in mathcad 11 / 15

[FanCG]

I tried running two downloaded PDE examples of mathcad 11 in mathcad 15, but both examples cannot be in good running, either intolerable time-consuming, or error informations on function-call .

how can I modify the codes to run them smoothly on mathcad 15?

[AlanStevens]

For the DisilaneDecomposition worksheet change Radau to BDF.

Alan

[FanCG]

thanks for your instruction. it does works! but the fitting degree does not seem as good as that of Radau() in mathcad 11, I will try regulating / adjusting some parameters of BDF()

[AlanStevens]

I've been trying, unsuccessfully, to identify why the NLINPDE worksheet doesn't work properly in MC15. I suspect a bug of some sort as it runs virtually instantly in MC11.

The problem seems to have something to do with the fact that MC15 doesn't like the use of u(1,t) in the boundary condition for v.x(1,t). If you simply replace this boundary condition with v.x(1,t) = 2t then the worksheet calculates instantly in MC15, producing the same results as MC11

Alan

[FanCG]

Seems that I need to look through the original reference paper to identify the b.c.

[ValeryOchkov]

May br this site help you

http://twt.mpei.ac.ru/TTHB/New-Chem-Kin/En-ChemKin.html