[cyhpku]

hi everyone. I'm new to fe41 and currently studying ibm in it.I already read Hrvoje Jasak's ppt but still confused at the tutorial case of movingCylinderInChannellco.

1.Jasak's ppt said "copy immersed boundary mesh (ibCylinder,{ftr,stl}) into constant/triSurface folder". I am confused at the ibCylinder.ftr . It read as follows:

1
(

cylinder
patch
)


96
(
(0.176776 -0.176776 -0.05)
(0.176776 -0.176776 0.05)
...
(-0.095671 -0.23097 -0.05)
)

96
(
((0 64 65) 0)
((65 1 0) 0)
...
((7 6 79) 0)
)


it seems that the first part is the list of coordinate of the vertex which is numbered from 0~95,the second part is a list of triangle faces defined by three vetexs, but what does the following 0 mean? for example, I know (0 64 65) is a triangle surface ,but what does the other 0 mean in((0 64 65) 0)?

2.If the lagrange vertexes are defined that way,how can I set up an ib structure that can defrom? For example,let half of the vertex of the cylinder move with prescribed velocity and let the other half move passively. Other ibm software like ibamr or ib2d gives structer like spring,beam...etc, how ib in fe41 work to deal with fsi ,or ib structers' passive deformation?