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<p class="MsoNormal"><span style="font-size:11.0pt">Hi,<br>
<br>
I have made a two-phase flow code which computes motion of two phases in one dimension, where the phases are allowed to intermix. This code relies on a finite difference Jacobian computed using the standard coloring I get from the DMDA object:<br>
<br>
da = PETSc.DMDA().create(<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> dim=(N_vertical,),<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> dof=3,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> stencil_width=1,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> )<br>
<br>
I now want to add a variable for the interphase height L_z in addition to a velocity u_v, giving the velocity of the vapor flowing in to the interface. The interface will move throughout the grid, meaning that these two variables will not be coupled to a fixed
set of grid cells, but will be coupled to different sets of three grid cells throughout the simulation.<br>
<br>
Questions:<br>
<br>
1. Is it possible to create a custom coloring to efficiently compute the finite difference Jacobian including the interphase height and vapor velocity?<br>
<br>
2. How do I revert to computing the full finite difference Jacobian with the purpose of testing if the interphase model works?<br>
<br>
Best regards,<br>
Eirik Jaccheri Høydalsvik<br>
Sintef ER and NTNU EPT<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
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