Some nitpicking:<br><br>1. I'm guessing you mean strain rate instead of strain since you're using velocity.<br>2. For step 8 it looks like you're missing the cell surface area and the normal (I think you should only have to calculate the scalar values to get the force you want).<br>
<br>As far as the compute derivatives part, make sure you're using a recent version as I made modifications to the vtkGradientFilter to do gradients of non-scalar (i.e. number of components > 1) and end up with a tensor of order 1 more than the input tensor. Let me know if you get unexpected results with that and I'll take a look.<br>
<br>Andy<br><br><div class="gmail_quote">On Fri, Oct 16, 2009 at 9:10 AM, Renato Elias <span dir="ltr"><<a href="mailto:rnelias@gmail.com">rnelias@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Folks,<br><br>I'm trying to integrate hydrodynamic forces on an immersed body. Point velocity and pressure fields come from a FEM solver. Ok, for this purpose, I'll need:<br><br>a). The body's surface<br>b). Stress tensor (computed as cell data)<br>
c). Body cell normals<br clear="all"><br>Here goes the pipeline I'm trying to use:<br><br>1. Load the volume data<br>2. Clean to grid (to remove parallel interfaces among mesh partitions)<br>3. Compute Derivatives (output tensor type = strain)<br>
4. Extract Surface<br>5. Generate Surface Normals<br>6. Point Data to Cell data (to convert point pressure in cell pressure)<br>7. Clip (to get only the body where I'd like to compute the forces)<br>8. from 7: Calculator (sigxx = -pressure+2*mu*Strain_0)<br>
<br>repeate step 8 for other components<br><br>Questions are:<br><br>-- Does it make sense? I'm asking it because I have some doubts about the output of some of the filters I'm using (mainly steps 3 and 5)<br><br>
-- Is there a more straightforward way to do the same thing?<br><br>Thanks for any help<br><font color="#888888"><br>-- <br>Renato N. Elias<br>===================================<br>High Performance Computing Center (NACAD)<br>
Federal University of Rio de Janeiro (UFRJ)<br>
Rio de Janeiro, Brazil<br><br>Sent from Rio De Janeiro, RJ, Brazil
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